(N-3,4)-dimethylphenyl-D-ribamine prodn. - by catalytic hydrogenation of e.g. D-ribonic acid (3,4)-dimethyl anilide

摘要

Prepn. of N-(3,4-dimethylphenyl)-D-ribamine of formula (I): comprises catalytic hydrogenation in inert solvent at 100-155 degrees C of either (a) a mixt. of 3, -dimethylaniline and/or 3,4-dinitrobenzene and a D-ribonic deriv. (II) (where R' is H or one R' together with R" forms a bond; R" is OH or R'"-O-, or forms a bond with one R'; R'" is 1-10C hydrocarbyl opt. substd. by OH) or (b) D-ribonic acid 3,4-dimethylanilide (III) (I; -C(O)- is -CH2-). (I) is an intermediate to vitamin B2. Process gives good yields, of pure (I) more simply, and economically than prior processes. Pref. catalyst contains Cu and/or CuO. (II) is pref. D-ribonic acid gamma-lactone.