Alpha-amino acid prodn. from amino nitrile - by single stage hydrolysis in presence of carbonyl catalyst

摘要

Prepn. of alpha-aminoacids (I) comprises catalytic hydrolysis of an alpha-aminonitrile (II) or its salts, in aq. soln. of >=1 carbonyl deriv. (III) as catalyst in the presence of OH ions. The concn. of OH ions is approx. equimolar to that of (II), and after reaction free (I) is extracted. Pref. (III) is 0.1-2, esp. 0.1-1 mole per mole (II) and the min. amt. of water is 1 mole per mole (II). Pref. the soln. is heated to 80 degrees C. (II) are esp. of formula RCH-(NH2)CN. (R is H, or opt. branched 1-12C hydrocarbyl opt. contg. >=1 heteroatom such as S, and opt. substd. by >=1 OH, NH2, COOH, phenyl, hydroxyphenyl, carboxamido, indolyl, iminazyl or guanidinyl, pref. at the end of the chain; R can also form with the alpha-N, a satd. heterocycle which can be substd. e.g. by OH). (I) are used in human and veterinary medicine, in nutrition and in soaps and cosmetics. Hydrolysis is in a single stage with no need to isolate the intermediate alpha-amino amide. (III) and the NH3 generated during hydrolysis can be recycled and conversions are almost quantitative. In an example, alanine was prepd. in 96.6% yield by hydrolysing alpha-aminopropionitrile hydrochloride in presence of acetone.