1. Tetrahydro-β-carboline alkaloid derivatives with a structure shown in the following general formula (Id) (a) wherein R6 represents hydrogen, hydroxy, amino or C1-C6 alkoxy; or (b) R6 represents phenyl, benzo[d][1,2,3]thiadiazol-7-yl, 4-methyl-1,2,3-thiadiazol-5-yl, 4-pyridyl, n-pentyl, tert-butyl or cyclopentyl, wherein the core structure of general formula (Id) has a (1S, 3S)-geometry.

2. Tetrahydro-β-carboline alkaloid derivatives according to claim 1, characterized in that the compound is: N'-((1S,3S)-1-methyl-2,3,4,9-tetrahydropyridino[3,4-b ]indol-3-formyl)benzo[d][1,2,3]thiadiazole-7-formylhydrazine (Id-1) 4-methyl-N'-((1S,3S)-1-methyl-2,3,4,9-tetrahydropyridino[3,4-h]indol-3 -fortnyl)- 1,2,3 - thiadiazole-5-formylhydrazine (Id-2) (1S,3S)-N'-isonicotinoyl-1-methyl-2,3,4,9-tetrahydropyridino[3,4-b]indol-3-formylhydrazine (Id-3) (1S,3S)-N'-benzoyl-1-methyl-2,3,4,9-tetrahydropyridino[3,4-b]indol-3-formylhydrazine (Id-4) (1S,3S)-N'-n-hexanoyl-1-methyl-2,3,4,9-tetrahydropyridino[3,4-b]indol-3-formylhydrazine (Id-5) (1S,3S)-N'-tert-valerl-1-methyl-2,3,4,9-tetrahydropyridino[3,4-b]indol-3-formylhydrazine (Id-6) (1S,3S)-N'-(cyclopentylformyl)-1-methyl-2,3,4,9-tetrahydropyridino[3,4-b]indol-3 - formylhydrazine (Id-7)

3. A concise method for preparing tetrahydro-β-carboline alkaloid derivatives (Id) according to claim 2, said method comprising: reacting hydrazide compound Ib-15 with acyl chloride to obtain the corresponding bishydrazide compound Id-1-Id-7: wherein R6 represents phenyl, benzo[d][1,2,3]thiadiazol-7-yl, 4-methyl-1,2,3-thiadiazol-5-yl, 4-pyridyl, n-pentyl, tert-butyl or cyclopentyl.

4. The method according to claim 3, wherein said method comprises: reacting methyl ester Ib-7 with hydrazine hydrate (80%) to obtain compound Ib-15:

5. Use of the tetrahydro-β-carboline alkaloid derivatives according to claim 1or 2 in the prevention and treatment of plant virus infections, or as fungicidal agent for plant, or as insecticide for plant.

6. The use according to claim 5, wherein the tetrahydro-β-carboline alkaloid derivatives effectively inhibit tobacco mosaic virus, chilli virus, rice virus, tomato virus, sweet potato virus, potato virus and cucurbits virus as well as maize dwarf mosaic virus.

7. The use according to claim 5, wherein the tetrahydro-β-carboline alkaloid derivatives show bactericidal activity against 14 kinds of pathogenic bacteria, which are cucumber fusarium wilt, Cercospora arachidicola, Macrophoma kawatsukai, Alternaria solani, Fusarium graminearumt, potato late blight, Sclerotinia scleotiorum, Botrytis cinerea, Rhizoctonia solani, Phytophthora capsici, Fusarium fujikuroi, Rhizoctonia cereali, Bipolaria maydis and Colletotrichum orbiculare.

8. The use according to claim 5, wherein the tetrahydro-β-carboline alkaloid derivatives show activity against armyworms, cotton bollworms, corn borers and culex pipiens.

Field of the Invention

[0001]The present invention relates to tetrahydro-β-carboline alkaloid derivatives, their preparation methods and use as fungicide, insecticide and use in the prevention and treatment of plant virus infections. The present invention relates to the technical field of pesticides.

Background of the Invention

[0002]The skeleton structures of β-carboline, dihydro-β-carboline and tetrahydro-β-carboline widely exist in natural products and drug molecules. Harmine and tetrahydroharmine belong to β-carboline and tetrahydro-β-carboline alkaloids respectively and are representative compounds of harmala alkaloids. Harmine was first separated from P. harmala L. This alkaloid shows cytotoxicity to leukemia cell lines HL60 and K562. Tetrahydroharmine is a fluorescent molecule separated from Malpighiacease plant Banisteriopsis caapi. This compound has weak inhibition to the re-uptake of 5-hydroxytryptamine. Harmaline is an agonist of the central nervous system and a reversible inhibitor of monoamine oxidase (MAO-A).

[0003]Currently, the research on β-carboline, dihydro-β-carboline and tetrahydro-β-carboline and substances similar to them focuses on anti-tumor, killing of human parasites and monoamine oxidase inhibitors. However, as far as we know, no document reports the activity of β-carboline, dihydro-β-carboline and tetrahydro-β-carboline and substances similar to them against plant viruses, and little was reported on their bactericidal activity and insecticidal activity. In the aspect of bactericidal activity: Fu Haibo et al from Gansu Agricultural University researched and found in 2007 that the extracting solutions of P. harmala L. in different solvents all have certain inhibiting effect to spore germination of four kinds of pathogenic bacteria, including Botrytis cinerea, Fusarium oxysporum, Alternaria solani and Cladosporium cucumerinum Ellis et Arthur, and their EC 50 is 0.060, 0.199, 0.105 and 0.223g/mL respectively (Fu Haibo, Ding Defang, Zhao Hongmei, Yang Shunyi, Grassland and Lawn, 2008, 1, 44-48.); in 2007, Wen Ren et al from Fudan University reported derivatives with a structure of 1-(3-indol)-1,2,3,4-tetrahydro-β-carboline and researched the in vitro activity of these derivatives against Pyricularia oryzae (CN101020688); in 2011, Zhang Yaomou et al from South China Agricultural University reported compounds with a structure of β-carboline-3-oxime ester and meanwhile studied the inhibitory activity of these compounds against Colletotrichum musae, Colletotrichum gloeosporioides and tomato late plight (Lu Shaoying, Zhang Yaomou, Synthetic Chemistry, 2011, 19 (6), 769-772.); in 2012, this research group again reported compounds with a structure of 1-p-trifluoromethylphenyl-β-carboline-3-carbonyl bishydrazide, but the quantity of the compounds was small and their bacteriostatic activity against Rhizoctorzia solani was tested only (Cai Ying, Huang Jianfeng, Zhang Meidan, Zeng Yong, Zhang Yaomo, Synthetic Chemistry, 2012, 20(6), 736-739.). In the aspect of insecticidal activity: in 2005, Zhao Xiaomeng et al from Beijing University of Agriculture reported the contact activity of the ethanol extract, chloroform extract and water extract of the overground part of P. harmala L. in the growing period against Myzus persicae, Macrosiphum rosivorum and Tetranychus cinnabarinus. The result is that their contact activity against spider mites is all above 95% at concentration of 10mg/mL, and that against two kinds of aphids is above 70% at concentration of 10mg/mL (Zhao Xiaomeng, Zeng Zhaohai, Chinese Agricultural Science Bulletin, 2005, 21(4), 278-279.); in 2010, Zhong Guohua et al from South China Agricultural University reported the insecticidal activity of 1,3-disubstituted β-carboline and tetrahydro-β-carboline derivatives against culex pipiens larvae and Lipaphis erysimi. To be specific, the LC 50 of the compounds with a structure of 1-phenyl substituted β-carboline and tetrahydro-β-carboline-3-methyl ester against culex pipiens larvae is 20.82mg/L and 23.98mg/L respectively, and the LC 50 against Lipaphis erysimi is 53.16mg/L and 68.05mg/L respectively (Zeng, Y; Zhang, Y M.; Weng, Q. F.; Hu, M. Y; Zhong G. H. Molecules 2010, 15, 7775-7791.).

[0004]CN102234277A and Kun Yao et al., European J. of Med. Chem., 46(8), 2011, pp 3237-3249 disclose 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carbonyl]-(amino-acid-acyl)hydrazine compounds with antithrombotic activity.

[0005]T. Arnason et al., "The Role of Natural Photosensitizers in Plant Resistance to Insects", In: Plant Resistance to Insects, Am. Chem. Soc., Washington, D.C, 208, 1983, pp 139-151, disclose the β-carboline compounds harman, norharman and harmalol.

Summary of the Invention

[0006]The object of the present invention is to provide tetrahydro-β-carbolinealkaloid derivatives and their preparation methods and use in the prevention and treatment of plant virus infections and killing of bacteria and insects. The tetrahydro-β-carbolinealkaloid derivatives of the present invention show very good activity against plant viruses and also show bactericidal activity and insecticidal activity. β-carboline, dihydro-β-carboline and tetrahydro-β-carbolinealkaloid derivatives are compounds with a structure shown in the following general formula (I):

[0007]In a first aspect, the inventon provides tetrahydro-β-carboline alkaloid derivatives that are compounds with structures shown in the following general formula I d : wherein:

(a) R 6< represents hydrogen, hydroxy, amino or C1-C6 alkoxy; or (b) R 6< represents phenyl, benzo[d][1,2,3]thiadiazol-7-yl, 4-methyl-1,2,3-thiadiazol-5-yl, 4-pyridyl, n-pentyl, tert-butyl or cyclopentyl, wherein the core structure of general formula (Id) has a (1S, 3S)-geometry.

[0008]Tetrahydro-β-carboline alkaloid derivative I b -15 can be prepared by the following method (Path 10): reacting methyl ester I b -7 with hydrazine hydrate (80%) to obtain compound I b -15.

[0009]Path 10:

[0010]In a second aspect, the invention provides a method for preparing the tetrahydro-β-carboline alkaloid derivatives I d -1 - I d -7 by the following method (Path 13): reacting hydrazide compound I b -15 with acyl chloride to obtain corresponding bishydrazide type compound I d -1-I d -7.

[0011]Path 13:

[0012]In the above general formulas, R 6< represents phenyl, benzo[d][1,2,3]thiadiazol-7-yl, 4-methyl-1,2,3-thiadiazol-5-yl, 4-pyridyl, n-pentyl, tert-butyl or cyclopentyl.

[0013]In a third aspect, the invention concerns the use of the tetrahydro-β-carboline alkaloid derivatives of formula (I d ) as defined herein in the prevention and treatment of plant virus infections, or as fungicidal agent for plant, or as insecticide for plant.

[0014]In a preferred embodiment of this use, the tetrahydro-β-carboline alkaloid derivatives of formula (I d ) as defined herein effectively inhibit tobacco mosaic virus, chilli virus, rice virus, tomato virus, sweet potato virus, potato virus and cucurbits virus as well as maize dwarf mosaic virus.

[0015]In another preferred embodiment of this use, the tetrahydro-β-carboline alkaloid derivatives of formula (I d ) as defined herein show bactericidal activity against 14 kinds of pathogenic bacteria, which are cucumber fusarium wilt, Cercospora arachidicola, Macrophoma kawatsukai, Alternaria solani, Fusarium graminearumt, potato late blight, Sclerotinia scleotiorum, Botrytis cinerea, Rhizoctonia solani, Phytophthora capsici, Fusarium fujikuroi, Rhizoctonia cereali, Bipolaria maydis and Colletotrichum orbiculare.

[0016]In another preferred embodiment of this use, the tetrahydro-β-carboline alkaloid derivatives of formula (I d ) as defined herein show activity against armyworms, cotton bollworms, corn borers and culex pipiens.

[0017]The tetrahydro-β-carboline alkaloid derivatives (I d ) described in the present invention are preferably chosen from the following compounds:

N'-((1S, 3S)-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-tricarboxylate) benzo [d] [1,2,3] thiadiazole-7-formylhydrazine (I d -1); 4-methyl-N'-((1S, 3S)-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-triformyl)-1, 2, 3-thiadiazole-5-formylhydrazine (I d -2); (1S, 3S)-N'-isonicotinoyl-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formylhydrazine (I d -3); (1S, 3S)-N'-benzoyl-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formylhydrazine (I d -4); (1S, 3S)-N'-n-hexanoyl-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3- formylhydrazine (I d -5); (1S, 3S)-N'-tert-valeryl-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formylhydrazine (I d -6); (1S, 3S)-N'-(cyclopentyl formyl)-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formylhydrazine (I d -7).

[0018]The compounds shown in general formula (I d ) of the present invention have excellent activity against plant viruses, can satisfactorily inhibit tobacco mosaic virus, chilli virus, rice virus, tomato virus, sweet potato virus, potato virus and cucurbits virus and maize dwarf mosaic virus, may effectively prevent and control virus diseases of tobacco, chilli, paddy, tomato, cucurbitaceous vegetable, grain, vegetable, bean and other crops, and is particularly applicable to the prevention and treating of tobacco mosaic. Tetrahydro-β-carboline alkaloid derivatives shown in general formula (I) have very high in vitro activity against TMV and also show very good in vivo activity against tobacco mosaic virus (TMV), and the in vivo activity of some of tetrahydro-β-carboline alkaloid derivatives against tobacco mosaic virus is obviously better than that of commercial variety virazole. Particularly, the activity of compounds I d -1, I d -6 and I d -7 against tobacco mosaic virus at concentration of 100µg/mL is equivalent to the activity of commercial variety ningnanmycin at concentration of 100µg/mL. As far as we know, it is also the first time to report tetrahydro-β-carboline alkaloid and their derivatives have activity against plant viruses.

[0019]The compounds shown in general formula (I d ) of the present invention can be used as inhibitors of plant viruses directly, or used by adding an agriculturally acceptable vector, or used by forming interactive compositions with other agents against plant viruses, such as: diazosulfide (BTH), tiadinil (TDL), 4-methyl-1,2,3-thiadiazole-5-formic acid (TDLA), DL-β-aminobutyric acid (BABA), virazole, ningnanmycin, phenanthroindolizidine alkaloid Antofine, linked triazole compounds XY-13 and XY-30, virus A, salicylic acid, polyhydroxy dinaphthaldehyde and amino oligosaccharin. Some of these compositions show a synergistic effect and some show an additive effect.

[0020]The compounds shown in general formula (I d ) of the present invention have the activity of killing armyworms, cotton bollworms and corn borers as well as culex pipiens.

[0021]The compounds shown in general formula (I d ) of the present invention show bactericidal activity against the following 14 kinds of pathogenic bacteria: cucumber fusarium wilt, Cercospora arachidicola, Macrophoma kawatsukai, Alternaria solani, Fusarium graminearumt, potato late blight, Sclerotinia scleotiorum, Botrytis cinerea, Rhizoctonia solani, Phytophthora capsici, Fusarium fujikuroi, Rhizoctonia cereali, Bipolaria maydis and Colletotrichum orbiculare.

[0022]The compounds shown in general formula (I d ) of the present invention can be used as insecticides and bactericides directly, or used by adding an agriculturally acceptable vector, or used in combination with other insecticides, miticides and bactericides, such as: tebufenpyrad, chlorfenapyr, etoxazole and fenpyroximate. Some of these compositions show a synergistic effect and some show an additive effect.

Detailed Description of the Embodiments

[0023]The following embodiments and bioassay results are intended to further illustrate but not to limit the present invention.

Embodiment 1 (not according to the invention): Synthesis of dihydro-P-carboline alkaloid harmalan

[0024]

Synthesis of indol-3-formaldehyde

[0025]Add 140mL of DMF to a 500mL single-necked flask, add 27mL of POCl 3 at 0 °C, then add 50mL of DMF solution containing 25g (214mmol) of indole and stir them overnight. Add 50mL of water and 150mL of 20% NaOH aqueous solution in turn and heat and reflux them for 6h. Pour the reaction solution into water and conduct suction filtration to obtain 20.6g of brown solid. The yield is 66% and the melting point is 190-192 °C (literature value: 190-192 °C);

1H NMR (400 MHz, CDCl 3 ) δ 10.08 (s, 1H, CHO), 8.80 (s, 1H, NH), 8.32-8.34 (m, 1H, Ar-H), 7.86 (d, 4< J HH = 2.8 Hz, 1H, Ar-H), 7.44-7.62 (m, 1H, Ar-H), 7.31-7.36 (m, 2H, Ar-H).

Synthesis of (E)-3-(nitrovinyl) indole

[0026]Add 20g (138mmol) of indol-3-formaldehyde, 5.3g (69mmol) of ammonium acetate and 200mL of nitromethane to a 500mL single-necked flask, and heat and reflux them for 8h. Add 200mL of water and 150mL of ethyl acetate and separate the liquid. Wash the organic phase with water, dry it and evaporate the solvent under a reduced pressure. Use dichloromethane for column chromatography under normal pressure to obtain 19.1g of yellow solid. The yield is 74% and the melting point is 170-171 °C;

1< 'H NMR (400 MHz, CDCl 3 ) δ 8.74 (s, 1H, NH), 8.30 (d, 3< J HH = 13.6 Hz, 1H, CH), 7.79-7.83 (m, 2H, CH and Ar-H), 7.69 (d, 4< J HH = 2.8 Hz, 1H, Ar-H), 7.48-7.50 (m, 1H, Ar-H), 7.33-7.38 (m, 2H, Ar-H),

Synthesis of tryptamine

[0027]Add 500mL of tetrahydrofuran to a 1000mL single-necked flask, and add 11.4g (300mmol) of lithium aluminum hydride and 9.4g (50mmol) of (E)-3-(nitrovinyl) indole. Heat and reflux them for 7h. Use water to quench lithium aluminum hydride not fully reacted. Conduct suction filtration, remove the solvent in the filtrate and add ethyl acetate and water to separate liquid. Wash the organic phase with a saturated saline solution, dry it with anhydrous sodium sulfate, remove solvent to obtain a red viscous substance, and dry it naturally to obtain 8.9g of brown solid. The yield is 89% and the melting point is 115-117 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 8.26 (s, 1H, NH), 7.62 (d, 3< J HH = 7.6 Hz, 1H, Ar-H), 7.36 (d, 3J HH = 8.0 Hz, 1H, Ar-H), 7.20 (t, 3< J HH = 7.6 Hz,1H, Ar-H), 7.12 (t, 3< J HH = 7.6 Hz,1H, Ar-H), 7.02 (s, 1H, Ar-H), 3.04 (t, 3< J HH = 6.4 Hz, 2H, CH 2 ), 2.91 (t, 3< J HH = 6.8 Hz, 2H, CH 2 ), 1.47 (s, 2H, NH 2 ).

Synthesis of harmalan

[0028]Add 0.5g (3.13mmol) of tryptamine, 40mL of dichloromethane and 2mL of triethylamine to a 100mL single-necked flask. Add 5mL of dichloromethane solution containing 0.27g (3.44mmol) of acetylchloride and react at room temperature for 5h. Wash the reaction solution with a saturated sodium bicarbonate aqueous solution, dry it with anhydrous sodium sulfate and remove the solvent. Add 20mL of toluene, 20mL of chloroform and 3mL of phosphorus oxychloride without the need of purification. Heat and reflux them for 7h. Add sodium carbonate to regulate the reaction solution to be alkaline. Extract the reaction solution with dichloromethane, and wash the organic phase with a saturated saline solution, dry it with anhydrous sodium sulfate and remove the solvent. Use dichloromethane/methanol (10: 1) for column chromatography under normal pressure to obtain 0.35g of brownish yellow solid. The yield is 60% and the melting point is 110-113 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 9.47 (s, 1H, NH), 7.60 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.48 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 7.31 (t, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.16 (t, 3< J HH = 8.0 Hz, 1H, Ar-H), 3.88 (t, 3< J HH = 8.4 Hz, 2H, CH 2 ), 2.95 (t, 3< J HH = 8.8 Hz, 2H, CH 2 ), 2.53 (s, 3H, CH 3 ): HRMS (ESI) calcd for C 12 H 13 N 2 (M+H) +< 185.1073, found 185.1077.

Embodiment 2 (not according to the invention): Synthesis of tetrahydroharmane and harmane.

[0029]

Synthesis of tetrahydroharmane

[0030]Add 8.1mL (43.75mmol) of 40% acetaldehyde aqueous solution, 250mL of water and 5 drops of concentrated sulfuric acid to a 500mL single-necked flask. Stir them at room temperature for 0.5h, add 3.50g (21.88mmol) of tryptamine and heat and reflux them for 7h. Add NaOH to regulate pH value to around 10, extract the solution with dichloromethane, wash the organic phase with a saturated saline solution, dry it with anhydrous sodium sulfate, remove the solvent, and use dichloromethane/methanol (5: 1) for column chromatography under normal pressure to obtain 2.53g of brown solid. The yield is 62% and the melting point is 173-175 °C;

1< H NMR (400 MHz, d 6 -DMSO) δ 10.68 (s, 1H, NH), 7.35 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.27 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 6.98-7.02 (m, 1H, Ar-H), 6.91-6.95 (m, 1H, Ar-H), 3.99-4.04 (m, 1H, CH NH), 3.33 (s, 1H, CHNH ), 3.14-3.19 (m, 1H, CH 2 NH), 2.81-2.87 (m, 1H, CH 2 NH), 2.51-2.62 (m, 2H, CH 2 CH 2 ), 1.36 (d, 3< J HH = 6.8 Hz, 3H, CH 3 CH); HRMS (ESI) calcd for C 12 H 15 N 2 (M+H) +< 187.1230, found 187.1231.

Synthesis of harmane

[0031]Add 0.85g (4.57mmol) of tetrahydrocarboline, 0.53g (4.57mmol) of maleic acid, 120mL of water and 0.85g of Pd/C to a 250mL single-necked flask. Heat and reflux them for 8h, conduct suction filtration, wash with water and regulate pH value of the filtrate with NaOH to 9-10 to obtain a large amount of white solid. Conduct suction filtration to obtain 0.5g of white solid. The yield is 60% and the melting point is 244-245 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 8.41(s, 1H, NH), 8.37 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 8.12 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.83 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.52-7.57 (m, 2H, Ar-H), 7.26-7.32 (m, 1H, Ar-H), 2.84 (s, 3H, CH 3 ): HRMS (ESI) calcd for C 12 H 11 N 2 (M+H) +< 183.0917, found 183.0915.

Embodiment 3 (not according to the invention): Synthesis of tetrahydroharmine

[0032]

Synthesis of quaternary ammonium salt

[0033]Add 0.5g (2.36mmol) of harmine, 120mL of ethyl acetate and 0.48g (2.83 mmol) of benzyl bromide to a 250mL single-necked flask. Heat and reflux them for 12h. Conduct suction filtration to obtain 0.67g of light yellow solid. The yield is 74% and the melting point is above 300 °C; 1< H NMR (400 MHz, d 6 -DMSO) δ 12.78 (s, 1H, NH ),

8.74 (d, 3< J HH = 6.4 Hz, 1H, Ar-H), 8.58 (d, 3< J HH = 6.8 Hz, 1H, Ar-H), 8.37 (d, 3< J HH = 8.8 Hz, 1H, Ar-H), 7.35-7.44 (m, 3H, Ar-H), 7.23 (d, 3< J HH = 7.2 Hz, 2H, Ar-H), 7.12 (d, 4< J HH = 1.0 Hz, 1H, Ar-H), 7.08 (dd, 3< J HH = 8.8 Hz, 4< J HH = 1.0 Hz, 1H, Ar-H), 5.98 (s, 2H, CH 2 ), 3.95 (s, 3H, OCH 3 ), 2.98 (s, 3H, CH 3 ).

Synthesis of N-benzyl tetrahydroharmine

[0034]Add 0.67g (1.75mmol) of quaternary ammonium salt and 150mL of methanol to a 250mL single-necked flask, and add 30mL of methanol solution containing 0.53g (14.0mmol) of sodium borohydride. Heat and reflux them for 15h. Remove the solvent and add dichloromethane and water to separate liquid. Wash the organic phase with a saturated saline solution, dry it with anhydrous sodium sulfate, remove the solvent, and use dichloromethane/methanol (20: 1) for column chromatography under normal pressure to obtain 0.47g of brown solid. The yield is 88% and the melting point is 147-149 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 7.68 (s, 1H, NH), 7.50-7.52 (m, 2H, Ar-H ), 7.43-7.47 (m, 3H, Ar-H), 7.36-7.40 (m, 1H, Ar-H), 6.90 (dd, 3< J HH = 8.8 Hz, 4< J HH = 2.4 Hz, 1H, Ar-H), 6.83 (d, 4< J HH = 2.4 Hz, 1H, Ar-H), 3.97 (d, 2< J HH = 13.6 Hz, 1H, CH 2 C 6 H 5 ), 3.81 3< J HH = 6.8 Hz, 1H, CHCH 3 ), 3.77 (d, 2< J HH = 13.6 Hz, 1H, CH 2 C 6 H 5 ), 3.22-3.29 (m, 1H, CH 2 CH 2 ), 2.85-2.95 (m, 2H, CH 2 CH 2 ), 2.68-2.74 (m, 1H, CH 2 CH 2 ), 1.61 (d, 3< J HH = 6.8 Hz, 1H, CHCH 3 ).

Synthesis of tetrahydroharmine

[0035]Add 0.70g (2.29mmol) of N-benzyl-protected tetrahydroharmine, 120mL oftrifluoroethanol and 0.70g of Pd/C to a 250mL single-necked flask, input hydrogen and stir them overnight. Remove the solvent, and use dichloromethane/methanol (10:1) for column chromatography under normal pressure to obtain 0.37g of light yellow viscous substance. The yield is 80% and the melting point is 195-197 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 7.64 (s, 1H, NH), 7.35 (d, 3< J HH = 8.8 Hz, 1H, Ar-H), 6.85 (d, 4< J HH = 2.0 Hz, 1H, Ar-H ), 6,77 (dd, 3< J HH = 8.4 Hz, 4< J HH = 2.4 Hz, 1H, Ar-H), 4.14-4.19 (m, 1H, CHCH 3 ), 3.84 (s, 3H, OCH 3 ), 3.33-3.39 (m, 1H, CH 2 CH 2 ), 3.01-3.07 (m, 1H, CH 2 CH 2 ), 2.66-2.78 (m, 2H, CH 2 CH 2 ), 1.65 (s, 1H, NH), 1.44 (d, 3< J HH = 6.8 Hz, 3H, CH 3 ): HRMS (ESI) calcd for C 13 H 17 N 2 O (M+H) +< 217.1335, found 217.1337.

Embodiment 4 (not according to the invention): Synthesis of harmol

[0036]

[0037]Add 0.5g (2.36mmol) of harmine, 18mL of glacial acetic acid and 18mL of 40% hydrobromic acid aqueous solution to a 100mL single-necked flask, and heat and reflux them for 10h. Use saturated sodium bicarbonate to regulate pH value to around 8 and generate precipitate. Conduct suction filtration to obtain 0.46g of yellow green solid. The yield is 98% and the melting point is above 300 °C;

1H NMR 400 MHz, d 6 -DMSO) δ 11.24 (s, 1H, NH), 9.72 (s, 1H, OH), 8.11 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.94 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.75 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 6.90 (d, 4< J HH = 1.2 Hz, 1H, Ar-H), 6.69 (dd, 3< J HH = 8.4 Hz, 4< J HH = 1.6 Hz, 1H, Ar-H), 2.69 (s, 3H, CH 3 ): HRMS (ESI) calcd for C 12 H 11 N 2 O (M+H) *< 199.0866, found 199.0867.

Embodiment 5 (not according to the invention): Synthesis of bromo and nitro-substituted harmane

Synthesis of bromo-harmane (I a -1 and I a -2)

[0038]

[0039]Add of 0.2g (1.10mmol) of harman and 10mL of glacial acetic acid to a 25mL single-necked flask, add 0.2g (1.10mmol) of NBS, and react at room temperature for 6h. Remove the solvent, wash with saturated sodium bicarbonate, extract with dichloromethane, dry the organic phase with anhydrous sodium sulfate, remove the solvent and use dichloromethane/methanol (40: 1→20: 1) in turn for column chromatography under normal pressure to obtain two kinds of white solid: solid I a -1 0.05g, yield 17%; 1< H NMR(400MHz, CDCl 3 )δ 8.36-8.49(m, 2H, NH and Ar-H), 8.04(d, 3< J HH =6.4Hz, 1H, Ar-H), 7.77-7.84(m, 1H, Ar-H), 7.70(d, 3< J HH =6.4Hz, 1H, Ar-H), 7.18(t, 3< J HH =6.4Hz, 1H, Ar-H), 2.88(s, 3H, CH 3 ). Solid I a -2 0.24 g, yield 83%, melting point 256-257 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 8.44 (s, 1H, NH), 8.39 (d, 3< J HH = 5.6 Hz, 1H, Ar-H), 8.24 (d, 4< J HH = 2.0 Hz, 1H, Ar-H), 7.78 (d, 3< J HH = 5.6 Hz, 1H, Ar-H), 7.63 (dd, 3< J HH = 8.4 Hz, 4< J HH = 2.0 Hz, 1H, Ar-H), 7.42 (d, 3< J HH = 8.8 Hz, 1H, Ar-H), 2.83 (s, 3H, CH 3 ): HRMS (ESI) calcd for C 12 H 10 BrN 2 (M+H) +< 261.0022, found 261.0026.

Synthesis of nitro-substituted harmane (I a -3 and I a -4)

[0040]

[0041]Add 0.4g (2.20mmol) of harman and 0.93g (10.99mmol) of sodium nitrate to a 50mL single-necked flask, add 20mL of trifluoroacetic acid, and stir them at room temperature for 6h. Add a saturated sodium bicarbonate aqueous solution to the reaction solution to regulate pH value to 10-11 and generate yellow precipitate, and conduct suction filtration to obtain 0.06g of yellow solid I a -3. The yield is 12% and the melting point is 207-210 °C.

1< H NMR (400 MHz, d 6 -DMSO) δ 11.77 (s, 1H, NH), 8.77 (d, 3< J HH = 7.6 Hz, 1H, Ar-H), 8.50 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 8.38 (d. 3< J HH = 5.2 Hz, 1H, Ar-H), 8.11 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.48 (t 3< J HH = 7.6 Hz, 1H, Ar-H), 2.92 (s, 3H, CH 3 ): HRMS (ESI) calcd for C 12 H 10 N 3 O 2 (M+H) +< 228.0768, found 228.0772. 0.36 g 0.36g of light yellow solid I a -4. The yield is 12% and the melting point is above 300 °C. 1< H NMR (400 MHz, d 6 -DMSO) δ 12.36 (s, 1H, NH), 9.30 (d, 4< J HH = 2.0 Hz, 1H, Ar-H), 8.41 (dd, 3< J HH = 8.8 Hz, 4< J HH = 3.0 Hz, 1H, Ar-H), 8.33 (d, 3< J HH = 5.6 Hz, 1H, Ar-H), 8.20 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.73 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 2.79 (s. 3H, CH 3 ): HRMS (ESI) calcd for C 12 H 10 N 3 O 2 (M+H) +< 228.0768, found 228.0767.

Embodiment 6 (not according to the invention): Synthesis of isopropylamino formate (1-methylpyridino [3,4-b] indol-7)-ester (I a -5)

[0042]

[0043]Add 0.5g (2.53mmol) of demethylated harmaline and 50mL of DMF to a 100mL single-necked flask, add 1.5mL of isopropyl isocyanate and 0.08 g (0.758mmol) of triethylamine, and stir them overnight. Add a saturated sodium chloride aqueous solution, extract with ethyl acetate, dry it with anhydrous sodium sulfate and remove the solvent. Use dichloromethane/methanol (20: 1) for column chromatography under normal pressure to obtain 0.50g of white solid. The yield is 70% and the melting point is above 300 °C;

1< H NMR (400 MHz, d 6 -DMSO) δ 11.58 (s, 1H, NH), 8.20 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 8.16 (d, 3< J HH = 8.8 Hz, 1H, Ar-H), 7.90 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.76 (d, 3< J HH = 8.0 Hz, 1H, NHCO), 7.27 (d, 4< J HH = 1.6 Hz, 1H, Ar-H), 6.95 (dd, 3< J HH = 8.4 Hz, 4< J HH = 2.0 Hz, 1H, Ar-H), 3.65-3.73 (m, 1H, CH), 2.75 (s, 3H, CH 3 ), 1.16 (d, 3< J HH = 6.4 Hz, 6H, (CH 3 ) 2 CH): HRMS (ESI) calcd for C 16 H 18 N 3 O 2 (M+H) +< 284.1394, found 284.1399.

Embodiment 7 (not according to the invention): Synthesis of dimethylcarbamate (1-methylpyridino [3,4-b] indol-7)-ester (I a -6)

[0044]

[0045]Add 0.4g (2.02mmol) of demethylated harmaline, 150mL of tetrahydrofuran, 0.31g (3.03mmol) of triethylamine and a catalytic amount of DMAP to a 250mL single-necked flask, stir them at room temperature for 0.5h, add 0.33g (3.03mmol) of acyl chloride and stir them overnight. Remove the solvent, add dichloromethane and water to separate liquid, wash the organic phase with a saturated saline solution, dry it with anhydrous sodium sulfate, remove the solvent, and use dichloromethane/methanol (10: 11) for column chromatography under normal pressure to obtain 0.48g of white solid. The yield is 89% and the melting point is 225-227 °C;

1< H NMR (400 MHz, d 6 -DMSO) δ 11.63 (s, 1H, NH), 8.20 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 8.17 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 7.91 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.30 (d, 4< J HH = 2.0 Hz, 1H, Ar-H), 6.97 (dd, 3< J HH = 8.4 Hz, 4< J HH = 2,1) Hz, 1H, Ar-H), 3.10 (s, 3H, CH 3 )), 2.94 (s, 3H, CH 3 ), 2.75 (s, 3H, CH 3 ): HRMS (ESI) calcd for C 1 H 16 N 3 O 2 (M+H) +< 270.1237, found 270.1240.

[0046]Compounds I a -7-I a -8 are completed through repeating the foregoing steps.

Acetate (1-methylpyridino [3,4-b] indol-7)-ester (I a -7)

[0047]White solid, yield 50%, melting point 237-240 °C;

1< H NMR (400 MHz, CDCl 3 ) δ 8.90 (s, 1H, NH), 8.23 (d, 3< J HH = 2.4 Hz, 1H, Ar-H), 7.78 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 7.70 (d, 3< J HH = 2.0 Hz, 1H, Ar-H), 7.16 (s, 1H, Ar-H), 6.93 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 2.76 (s, 3H, CH 3 ), 2 42 (s, 3H, CH 3 CO). HRMS (ESI) calcd for C 14 H 13 N 2 O 2 (M+H) +< 241.0972, found 241.0970.

Tert-valerate (1-methylpyridino [3,4-b] indol-7)-ester (I a -8)

[0048]White solid, yield 85%, melting point 221-222 °C;

1< H NMR. (400 MHz, CDCl 3 ) δ 8.63 (s, 1H, NH), 8.30 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.75 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 7.34 (d, 3< J HH = 4.8 Hz, 1H, Ar-H), 7.09 (s, 1H, Ar-H), 6.86 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 2.73 (s, 3H, CH 3 ), 1.45 (s, 9H, C(CH 3 ) 3 ): HRMS (ESI) calcd for C 17 H 19 N 2 O 2 (M+H) +< 283.1441, found 283.1446.

Embodiment 8 (not according to the invention): Synthesis of (S)-3-methyl-2-carbobenzoxyaminobutyrate - (1 - methylpyridino [3,4-b] indol-7-ester (I a -9)

[0049]

[0050]Add 0.80g (3.03mmol) of amino acid and 150mL of dichloromethane to a 250mL single-necked flask, and add 0.41g (4.04mmol) of triethylamine, 0.76g (4.04mmol) of EDCI (1-ethyl-(3-dimethylaminopropyl) carbonyldiimide hydrochloride) and 0.50g (4.04mmol) of DMAP (4-dimethylaminopyridine) and stir them overnight. Wash them with water, dry them with anhydrous sodium sulfate, remove the solvent, and use dichloromethane/methanol (20: 1) for column chromatography under normal pressure to obtain 0.8g of white solid. The yield is 92% and the melting point is 69-71 °C;

1< H NMR. (400 MHz, CDCl 3 ) δ 8.54 (s, 1H, NH), 8.34 (d, 3< J HH = 5.2 Hz, 1H, Ar-H), 7.92 (d, = 8.4 Hz, 1H, Ar-H), 7.66 (d, 3< J HH = 4.8 Hz, 1H, Ar-H), 7.35-7.38 (m, 5H, Ar-H), 7.19(s, 1H, Ar-H), 6.94 (d, 3< J HH = 8.4 Hz, 1H, Ar-H), 5.39 (d, 3< J HH = 8.4 Hz,1H, NHCO), 5.17 (s, 2H, CH 3 ), 4.54-4.66 (m, 1H, CHNH), 2.77 (s, 3H, CH 3 ), 2.38-2.50 (m, 1H, CH(CH 3 ) 2 ), 1.14 (d, 3< J HH = 6.8 Hz, 3H, CH(CH 3 ) 2 ), (d, 3< J HH = 6.8 Hz, 3H, CH(CH 3 ) 2 ): HRMS (ESI)calcd for C 25 H 26 N 3 O 4 (M+H) +< 432.1918, found 432.1920.

Embodiment 9 (not according to the invention): (1S, 3S)-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formic acid (I b -1)

[0051]

[0052]Add 20g (98.0mmol) of L-tryptophan, 500mL of water, 2mL of concentrated sulfuric acid and 20mL of 40% acetaldehyde aqueous solution to a 1000mL single-necked flask, stir them at room temperature overnight, use strong aqua to regulate pH value to 6-7, separate out white solid and conduct suction filtration to obtain 16.7g of white solid. The yield is 74% and the melting point is 78-280 °C; 1< H NMR (400 d 6 -DMSO) δ 11.11 (s, 1H, COOH), 7.45 (d, 3< J HH = 7.8 Hz, 1H, Ar-H), 7.34(d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.09 (t, 3< J HH = 7.6 Hz, 1H, Ar-H), 7.00 (t. 3< J HH = 7.2 Hz, 1H, Ar-H), 4.52 (q, 3< J HH = 6.4 Hz, 1H, CH), 3.61 (dd. 3< J HH = 11.6 Hz, 3< J HH =4.4 Hz, 1H, CH), 3.16 (dd, 2< J HH = 16.0 Hz, 3< J HH = 4.0 Hz, 1H, CH 2 ), 2.74-2.81 (m, 1H, CH 2 ), 1.62 (d. 3< J HH = 6.4 Hz, 3H, CH 3 ); HRMS (ESI) calcd for C 13 H 15 N 2 O 2 (M+H) +< 231.1128, found 231,1132.

[0053]Compounds I b -2 and I b -3 are completed through repeating the foregoing steps.

(1R, 3R)-1-methyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formic acid (I b -2)

[0054]White solid, yield 76%, melting point 285-287 °C;

1< H NMR (400 MHz, d 6 -DMSO) δ 11.20 (s, 1H, COOH), 7.44 (d, 3< J HH = 7.6 Hz, 1H, Ar-H), 7.35(d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.09 (t, 3< J HH = 7.6 Hz, 1H, Ar-H), 7.00 (t, 3< J HH = 7.6 Hz, 1H, Ar-H), 4.56 (q. 3< J HH = 6.4 Hz, 1H, CHCH 3 ), 3.64 (dd, 3< J HH 12.0 Hz, 3< J HH = 4.8 Hz, 1H, CH), 3.18 (dd, 3< J HH = 16.0 Hz, 3< J HH = 4.4 Hz, 1H, CH 2 ), 2.76-2.83 (m, 1H, CH 2 ), 1.64 (d, 3< J HH = 6.4 Hz, 3H, CH 3 ): HRMS (ESI) calcd for C 13 H 15 N 2 O 2 (M+H) +< 231.1128, found 231.1132.

(1S, 3S)-1-ethyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formic acid (I b -3)

[0055]2.67g of white solid, yield 44%, melting point 277-280 °C;

1< H NMR (400 MHz, d 6 -DMSO) δ 10.92 (s, 1H, COOH), 7.43 (d, 3< J HH = 7.6 Hz, 1H, Ar-H ), 7.32 (d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.05-7.08 (m, 1H, Ar-H), 6.96-7.00 (m, 1H, Ar-H), 4.32-4.33 (m, H, CHNH), 3.54 (dd, 3< J HH =11.6 Hz, 3< J HH = 4.4 Hz, 1H, CHCO), 3.10 (dd, 3< J HH = 15.6 Hz, 3< J HH = 4.0 Hz, 1H, CH 3 ), 2.70-2.78 (m, 1H, CH 2 ), 2.12-2.20 (m, 1H, CH 2 CH 3 ), 1.83-1.90 (m, 1H, CH 2 CH 3 ), 1.01 (t, 3< J HH = 7.2 H 2 , 3H, CH 2 CH 3 ). HRMS (ESI) calcd for C 14 H 17 N 7 O 2 (M+H) +< 245.1285, found 245.1289.

Embodiment 10 (not according to the invention): Synthesis of 2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formic acid (I b -4)

[0056]

[0057]Add 10.00g (49mmol) of L-tryptophan, 1.96g (49mmol) of NaOH and 100mL of water to a 250mL single-necked flask, and add 5mL of 30% formaldehyde aqueous solution. Heat and reflux them for 3h. Use 3M diluted hydrochloric acid to regulate pH value to around 5 and generate precipitate, conduct suction filtration, wash the filter cakes with water and dry them to obtain 8.32g of white solid. The yield is 88% and the melting point is 278-279 °C;

1< H NMR (400 MHz, d 6 -DMSO) δ 10.97 (s, 1H, COOH), 7.45 (d, 3< J HH = 7.8 Hz, 1H, Ar-H), 7.34(d, 3< J HH = 8.0 Hz, 1H, Ar-H), 7.09 (t, 3< J HH = 7.2 Hz, 1H, Ar-H), 7.00 (t, 3< J HH = 7.2 Hz, 1H, Ar-H), 4.25 (d, 3< J HH = 15.6 Hz, 1H, NHCH 2 ), 4.18 (d, 2< J HH = 15.6 Hz, 1H, NHCH 2 ), 3.62 (dd, 3< J HH = 10.4 Hz, 3< J HH = 4.8 Hz, 1H, CH), 3.15 (dd, 2< J HH = 16.4Hz, 3< J HH = 4.8 Hz, 1H, CH 2 ), 2.83 (dd, 3< J HH = 15.6 Hz, 3< J HH = 10.8 Hz, 1H, CH 2 ): HRMS (ESI) calcd for C 12 H 13 N 2 O 2 (M +< H) +< 217.0972, found 217.0969.

Embodiment 11 (not according to the invention): Synthesis of (1S, 3S)-1-phenyl-2,3,4,9-tetrahydropyridino [3,4-b] indol-3-formic acid (I b -5)

[0058]

[0059]Add 2.5g (12.3mmol) of L-tryptophan, 50mL of glacial acetic acid and 1.5g (13