- PROCESS FOR THE PREPARATION OF TAPENTADOL
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Disclosed herein is an improved process for the preparation of 3-[(2R,3R)-1-(dimethylamino)-2-methylpentan-3-yl]phenol of Formula-I and its pharmaceutically acceptable salt which comprises the reaction of (S)-1-(dimethylamino)-2-methylpentan-3-one of formula VIII with 3-bromo anisole of formula II under Grignard conditions to get the compound (2S, 3R)-1-(dimethylamino)-3-(3-methoxyphenyl)-2-methyl pentan-3-ol of formula V followed by activation of the —OH group of the formula V to convert into sulfonate esters of formula IX, which are on reductive deoxygenation to yield (2R,3R)-3-(3-methoxyphenyl)-N,N,2-trimethylpentan-1-amine of formula VII and demethylation of formula VII to obtain the compound 3-[(2R,3R)-1-(dimethylamino)-2-methylpentan-3-yl]phenol of Formula-1.
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Paragraph 0048; 0049; 0050
(2013/06/05)
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- PROCESS FOR THE PREPARATION OF TAPENTADOL
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Disclosed herein is an improved process for the preparation of 3-[(2R,3R)-1- (dimethylamino)-2-methylpentan-3-yl] phenol of Formula - I and its pharmaceutically acceptable salt which comprises the reaction of (S)-1-(dimethylamino)-2-methylpentan- 3-one of formula VIII with 3 - bromo anisole of formula II under Grignard conditions to get the compound (2S, 3R)-1- (dimethylamino)-3-(3-methoxyphenyl)-2-methyl pentan-3- ol of formula V followed by activation of the -OH group of the formula V to convert into sulfonate esters of formula IX, which are on reductive deoxygenation to yield (2R,3R)-3- (3-methoxyphenyl)-N,N,2-trimethylpentan-1 -amine of formula VII and demethylation of formula VII to obtain the compound 3-[(2R,3R)-1-(dimethylamino)-2-methylpentan-3- yl]phenol of Formula - 1.
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Page/Page column 14-15
(2012/03/11)
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- PREPARATION OF (2R,3R)-3-(3-METHOXYPHENYL)-N,N,2-TRIMETHYLPENTANAMINE
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The present invention relates to an improved process for the preparation of (2R,3R)-3- (3-methoxyphenyl)-N,N,2-trimethylpentanamine which is an intermediate for the preparation of the analgesic tapentadol.
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Page/Page column 9
(2008/06/13)
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- PROCESS FOR THE PREPARATION OF (1R,2R)-3-(3-DIMETHYLAMINO-1-ETHYL-2-METHYL-PROPYL)-PHENOL
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The present invention relates to a process for the preparation of (1 R,2R)-3- dimethylamino-1-ethyl-2-methyl-propyl)-phenol.
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Page/Page column 20-21
(2008/06/13)
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- SEPARATION OF STEREOISOMERIC N,N-DIALKYLAMINO-2-ALKYL-3-PHENYL ALKANES
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The invention relates to a method for isolating a stereoisomer from a mixture comprising two stereoisomers of general formulas (I-A) and (I-A') and/or two stereoisomers of general formulas (I-B) and (I-B'), wherein R1, R2, and R3 are identical or different and are selected among the group comprising -H, -F, -Cl, -C1-C6 alkyl, -S-C1-C6 alkyl, -OH, -O-C1-C6 alkyl, -O-C1-C6 alkylene-phenyl, -OCO-C1-C6 alkyl, -OCON(C1-C6 alkyl)2, and -O-SiR8R9R10 (wherein R8, R9, and R10 are identical or different, representing -C1-C6 alkyl or -phenyl); R4 represents -H or -C1-C6 alkyl; R5 represents -C1-C6 alkyl; and R6 and R7 are identical or different, representing -H or -C1-C6 alkyl; or the salts thereof with organic or inorganic acids. The inventive method encompasses step (a) in which the mixing ratio of the stereoisomers in the mixture is influenced such that at least one of said stereoisomers is provided with excess enantiomers.
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Page/Page column 17
(2008/06/13)
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