Stable pharmaceutical compositions comprising a compound of Formula (I) or a stereoisomer or a pharmaceutically acceptable derivative thereof are disclosed. Formula (I)

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Stable pharmaceutical compositions comprising a compound of Formula (I) or a stereoisomer or a pharmaceutically acceptable derivative thereof are disclosed. Formula (I)

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A novel process for preparation of Deutetrabenazine ((RR, SS)-1,3,4,6,7-11b-Hexahydro-9,10-di(methoxy-d.sub.6)-3-(2-methylpropyl)-2H-benzo [a] quinolizin-2-one) of formula I comprises of methylation of N-(2-(3,4-dihydroxy-phenyl)-ethyl)-formamide compound of formula III with deuteriated methanol (CD.sub.3OD or CD.sub.3OH) to obtain d.sub.6-N-(2-(3,4-dimethoxy-phenyl)-ethyl)-formamide compound of formula IV; cyclization of d.sub.6-N-(2-(3,4-dimethoxy-phenyl)-ethyl)-formamide in presences of dehydrating agent to obtain d.sub.6-6,7-Dimethoxy-3,4-dihydroisoquinoline compound of formula V; reacting d.sub.6-6,7-Dimethoxy-3,4-dihydroisoquinoline compound of formula V with 2-acetyl-N,N,N,4-tetramethyl-1-pentanaminium iodide compound of formula VI.

A novel process for preparation of Deutetrabenazine ((RR, SS)-1,3,4,6,7-11b-Hexahydro-9,10-di(methoxy-d.sub.6)-3-(2-methylpropyl)-2H-benzo [a] quinolizin-2-one) of formula I comprises of methylation of N-(2-(3,4-dihydroxy-phenyl)-ethyl)-formamide compound of formula III with deuteriated methanol (CD.sub.3OD or CD.sub.3OH) to obtain d.sub.6-N-(2-(3,4-dimethoxy-phenyl)-ethyl)-formamide compound of formula IV; cyclization of d.sub.6-N-(2-(3,4-dimethoxy-phenyl)-ethyl)-formamide in presences of dehydrating agent to obtain d.sub.6-6,7-Dimethoxy-3,4-dihydroisoquinoline compound of formula V; reacting d.sub.6-6,7-Dimethoxy-3,4-dihydroisoquinoline compound of formula V with 2-acetyl-N,N,N,4-tetramethyl-1-pentanaminium iodide compound of formula VI.

The present application relates to processes for making (2R,3R,11bR)-3-isobutyl-9,10-dimethoxy-2,3,4,6,7,11b -hexahydro-1H-pyrido[2,1-a]isoquinolin-2-yl (S)-2-amino-3-methylbutanoate di(4-methylbenzenesulfonate), which is an inhibitor of vesicular monoamine transporter 2 (VMAT2) useful in the treatment of hyperkinetic movement disorders such as tardive dyskinesia (TD).

The present invention relates to a class of compounds that serve as VMAT2 inhibitors, and relates in particular to a compound represented by formula (I), or a stereoisomer or pharmaceutically acceptable salt thereof, and a preparation method therefor, as well as the use thereof in the preparation of a medicament for treating diseases related to VMAT2.

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The present invention relates to new benzoquinoline inhibitors of vesicular monoamine transporter 2 (VMAT2), pharmaceutical compositions thereof, and methods of use thereof.

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The present invention relates to new benzoquinoline inhibitors of vesicular monoamine transporter 2 (VMAT2), pharmaceutical compositions thereof, and methods of use thereof.

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The present invention relates to new methods of manufacturing benzoquinoline inhibitors of vesicular monoamine transporter 2 (VMAT2), and intermediates thereof.

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The present invention relates to new methods of manufacturing benzoquinoline inhibitors of vesicular monoamine transporter 2 (VMAT2), and intermediates thereof.

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