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]lSOQUINOLIN-2-YL 2-AMINO-3-METHYLBUTANOATE DI(4-METHYLBENZENESULFONATE)
Provided herein are processes for the 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), or a solvate, hydrate, or polymorph thereof.
1 .- 31 . (canceled)
32 . A VMAT2 inhibitor that is (S)-(2R,3R,1bR)-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) prepared by a method comprising the steps of:
(a) adding p-toluenesulfonic acid to a solution comprising the free base 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 and acetonitrile; and
(b) filtering (S)-2-amino-3-methyl-butyric acid (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinolin-2-yl ester ditosylate salt from the solution.
33 . The VMAT inhibitor according to claim 32 , further comprising the step of heating the solution prior to adding p-toluenesulfonic acid.
34 . The VMAT inhibitor according to claim 33 , wherein heating is at 45° C. to 55° C.
35 . The VMAT inhibitor according to claim 32 , wherein adding p-toluenesulfonic acid is conducted as a solution comprising p-toluenesulfonic acid and acetonitrile.
36 . The VMAT inhibitor according to claim 32 , further comprising heating to 45° C. after adding p-toluenesulfonic acid.
37 . The VMAT inhibitor according to claim 32 , further comprising the step of drying (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) under vacuum.
38 . The VMAT inhibitor according to claim 37 , wherein drying under vacuum is conducted at 50° C.
39 . The VMAT inhibitor according to claim 32 , wherein (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) having an impurity profile comprising total impurities in an amount that is no greater than about 5% by weight.
40 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises total impurities in an amount that is no greater than about 4% by weight.
41 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises total impurities in an amount that is no greater than about 3% by weight.
42 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises total impurities in an amount that is no greater than about 2% by weight.
43 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises total impurities in an amount that is no greater than about 1% by weight.
44 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises total impurities in an amount that is no greater than about 0.5% by weight.
45 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises one or more impurities chosen from: (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, (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-aminopropanoate, and (S)-(2S,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.
46 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises (R)-(2R,3R,11bR)-3-isobutyl-9,10,11b-trimethoxy-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl 2-amino-3-methylbutanoate.
47 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises 6,7-dimethoxy-3,4-dihydroisoquinoline.
48 . The VMAT2 inhibitor of claim 39 , wherein the impurity profile comprises (S)-(2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-7-oxo-2,3,4,6,7,11b-hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl-2-amino-3-methylbutanoate.
49 . The VMAT2 inhibitor of claim 39 , having an impurity profile comprising one or more impurities chosen from metal-based impurities.
50 . The VMAT inhibitor according to claim 39 , wherein the impurity is an organic solvent.
51 . The VMAT2 inhibitor of claim 39 , having an impurity profile comprising one or more impurities chosen from dimethylamine, formaldehyde, ethyl chloride, and isopropyl chloride.
52 . The VMAT inhibitor according to claim 32 , wherein (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) has a weight loss on drying (LOD) of no greater than about 5% by weight.
53 . The VMAT2 inhibitor of claim 52 , having a weight loss on drying (LOD) of no greater than about 3% by weight.
54 . The VMAT2 inhibitor of claim 52 , having a weight loss on drying (LOD) of no greater than about 2% by weight.
55 . The VMAT2 inhibitor of claim 52 , having a weight loss on drying (LOD) of no greater than about 1% by weight.
56 . A pharmaceutical composition comprising (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) of claim 32 and a pharmaceutically acceptable carrier.
57 . A pharmaceutical composition comprising (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) of claim 39 and a pharmaceutically acceptable carrier.
58 . A pharmaceutical composition comprising (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) of claim 41 and a pharmaceutically acceptable carrier.
59 . A pharmaceutical composition comprising (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) of claim 45 and a pharmaceutically acceptable carrier.
60 . A pharmaceutical composition comprising (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) of claim 52 and a pharmaceutically acceptable carrier.
61 . A pharmaceutical composition comprising (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) of claim 54 and a pharmaceutically acceptable carrier.