SELECTIVE CATALYTIC-HYDROGENATION OF AROMATIC NITRO-GROUPS IN THE PRESENCE OF ACETYLENES - SYNTHESIS OF (3-AMINOPHENYL)ACETYLENE VIA HYDROGENATION OF DIMETHYLCARBINOL SUBSTITUTED (3-NITROPHENYL)ACETYLENE OVER HETEROGENEOUS METALLIC RUTHENIUM CATALYST

Heterogeneous metallic ruthenium catalyst was found to be selective for preferential hydrogenation of aromatic nitro groups in the presence of acetylenes. Thus, 2-methyl-4-(3-nitrophenyl)-3-butyn-2-ol was hydrogenated to 2-methyl-4-(3-aminophenyl)-3-butyn-2-ol in essentially quantitative yields. Removal of the dimethylcarbinol blocking group to afford (3-aminophenyl)acetylene was achieved by simple heating in the presence of a catalytic amount of caustic. (S-Nitrophenyl)acetylene itself was initially hydrogenated to (3-aminophenyl)acetylene, but the catalyst was poisoned through strong adsorption. © 1979, American Chemical Society. All rights reserved.