Synthetic methods for preparation of (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate di(4-methylbenzenesulfonate)

Patent metadata

Field	Value
Publication number	US-10160757-B2
Application number	US-201615388960-A
Country	US
Kind code	B2
Filing date	Dec 22, 2016
Priority date	Dec 23, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Provided herein are processes for the preparation of (S)-(2R,3R,11bR-3-isobuty-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate di(4-methylbenzenesulfonate), or a solvate, hydrate, or polymorph thereof.

First claim

What is claimed is:

1. A method for preparing (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate di(4-methylbenzenesulfonate), with at least about 95% purity; comprising: (a) reacting (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride with a base, and (b) reacting the product of (a) with p-toluenesufonic acid.

2. The method of claim 1 , wherein the base is sodium hydrogen carbonate.

3. The method of claim 1 , wherein the reaction of the product of (a) with p-toluenesulfonic acid is conducted in a second solvent.

4. The method of claim 1 , further comprising the step of reacting (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate under conditions suitable to form (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride, via a deprotection step, before the step of reacting (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride with a base.

5. The method of claim 4 , wherein the deprotection step of (S)-(2R,3R, 11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate is conducted in the presence of an acid.

6. The method of claim 5 , wherein the acid comprises a solution of hydrogen chloride in dioxane or 2-methyltetrahydrofuran.

7. The method of claim 4 , further comprising the step of adding a base.

8. The method of claim 7 , wherein the base is sodium hydrogen carbonate.

9. The method of claim 4 , further comprising adding an acid.

10. The method of claim 9 , wherein the acid is a solution of hydrogen chloride in propan-2-ol.

11. The method of claim 4 , further comprising the step of crystallizing (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride.

12. The method of claim 1 , further comprising the step of reacting (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol or a salt thereof with a tert-butoxycarbonyl protected amino acid under conditions suitable to form (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate.

13. The method of claim 12 , wherein the reaction of (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7, 11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol to form (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate is conducted using a salt of (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol.

14. The method of claim 13 , wherein the salt of (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-2]isoquinolin-2-ol is (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol (S)-(+) camphorsulfonate.

15. The method of claim 12 , wherein the tert-butoxycarbonyl protected amino acid is L-valine.

16. The method of claim 12 , wherein the reaction of (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol or a salt thereof to form (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate is conducted in the presence of 4-dimethylaminopyridine.

17. The method of claim 1 , further comprising the step of reacting 3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol with a chiral resolving agent to form (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol or a salt thereof prior to the reaction with a tert-butoxycarbonyl protected amino acid.

18. The method of claim 17 , wherein the chiral resolving agent is (1S)-(+)-camphorsulfonic acid.

19. The method of claim 17 , further comprising the step of crystallizing (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol (1 S)-(+)-camphorsulfonic acid.

20. The method of claim 1 , further comprising the step of reducing 3-isobutyl-9,10-dimethoxy-3,4,6,7-tetrahydro-1H-pyrido[2,1-a]isoquinolin-2(11bH)-one to form 3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol prior to the reaction with a chiral agent.

21. The method of claim 20 , further comprising sodium borohydride as reducing agent.

22. The method of claim 20 , further comprising the step of crystallizing 3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol.

23. The method of claim 1 , further comprising the step of reacting 6,7-dimethoxy-3,4-dihydroisoquinoline or a salt thereof with 3-((dimethylamino)methyl)-5-methylhexan-2-one or a salt thereof to form 3-isobutyl-9,10-dimethoxy-3,4,6,7-tetrahydro-1H-pyrido[2,1-a]isoquinolin-2(11bH)-one prior to the reduction step.

24. The method of claim 23 , further comprising the step of reacting 3-((dimethylamino)methyl)-5-methylhexan-2-one salt with a base prior to the reaction with 6,7-dimethoxy-3,4-dihydroisoquinoline or a salt thereof.

25. The method of claim 23 , wherein the salt of 3-((dimethylamino)methyl)-5-methylhexan-2-one is oxalate or citrate.

26. A method for preparing (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate di(4-methylbenzenesulfonate), with at least about 95% purity; comprising the steps of (a) reacting (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-ol or a salt thereof with a suitable protected L-valine to form (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7, 11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate; (b) deprotecting (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate to form (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride; and (c) reacting (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride with a base, and (d) reacting the product of (c) with p-toluenesulfonic acid to give (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate di(4-methylbenzenesulfonate).

27. A method for preparing (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate di(4-methylbenzenesulfonate) with at least about 95% purity; comprising the steps of (a) crystallizing (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate dihydrochloride; (b) reacting (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoat

Assignees

• Neurocrine Biosciences Inc
• Neuroscrine Biosciences Inc

Inventors

• Mcgee Kevin
• Li Bin-Feng

Classifications

• C07D471/04 Primary

  Ortho-condensed systems · CPC title