N-Substd. aminoacid prepn., used in sweeteners and pharmaceuticals - by oxidn. of corresp. amino-alcohol with hypochlorite in presence of TEMPO

摘要

Prepn. of N-substd. amino-acids of formula R3CH(NR1R2)(CH2)nCOOH (I) by oxidn. of corresp. amino-alcohol of formula (II) in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and hypochlorite soln. R1-R3, m, n are not defined. Pref. R1 = N, 1-6C alkyl or benzyl; R2 = H, 1-6C alkyl, benzyl, formyl, COR4 or CO2R5; or R1+R2 = phthaloyl, maleyl or malonyl; R3 = H, 1-6C alkyl (opt. interrupted or substd. by heteroatoms such as N, O or S which are opt. substd. by 1-6C alkyl, benzyl, formyl, COR4 or CO2R5), benzyl (opt. substd. by OH, F, Cl, Br or NO2), phenyl, naphth-2-ylmethyl, pyrid-3-ylmethyl, thienyl, acylamino(1-6C)alkyl, 1-6C alkyloxycarbonylamino(1-6C)alkyl, 6 or 7C aryloxycarbonylamino(1-6C)alkyl, imidazol-4-ylmethyl or indol-3-ylmethyl; or R1+R3 complete a 4-7 membered ring opt. contg. other heteroatoms (N,O, or S); R4 = 1-6C alkyl, phenyl, benzyl, NH2, nitrophenyl or nitrobenzyl; R5 = 1-6C alkyl, phenyl, benzyl, nitrophenyl or nitrobenzyl; and n = 0-2.