PROCESS FOR THE PREPARATION OF CARBIDOPA

摘要

The invention relates to a process for the preparation of (-) - (L) -3- (3,4-dihydroxyphenyl) -2-hydrazino-2 -methyl propionic acid (carbidopa) of the formula (II) by using 3, 3 -pentamethylene oxaziridine of the formula (IV), which comprises reacting L-a-methyldopa methyl ester of the formula (III) with 3,3-penta- methylene oxaziridine of the formula (IV), isolating the thus-obtained (+) - (L) -2- (N' - cyclohexylidene-hydrazino) -3- (3 , 4-dihydroxy phenyl) -2 -methyl propionic acid methyl ester of the formula (I) (I) and subjecting it to hydrolysis with an acid. (+) - (L) -2- (N' -cyclohexylidene-hydrazino) -3-(3,4-dihydroxyphenyl) -2-methyl propionic acid methyl ester of the formula (I) is a new intermediate . (-) - (L)-3-(3,4-dihydroxyphenyl) -2-hydrazino-2- methyl propionic acid (carbidopa) of the formula (XI) thus obtained is a valuable therapeutic active ingredient having the international non-proprietary name carbidopa.