4-Aminobenzonitrile → 4-Cyanophenylhydrazine Hydrochloride

Participants

Reaction Conditions

Reaction Steps

To a cooled (-15° C.) and stirred suspension of 4-aminobenzonitrile (50 g, 423 mmol) in concentrated hydrochloric acid (550 ml) was added dropwise a solution of sodium nitrite (31.5 g, 457 mmol) in water (200 ml) at such a rate as to maintain the temperature below -10° C. After the addition was finished, the reaction mixture was quickly filtered to remove solids and the filtrate was added portionwise to a cooled (-20° C.) and stirred solution of tin (II) chloride dihydrate (477 g, 2.1 mol) in concentrated hydrochloric acid (370 ml) at such a rate as to maintain the temperature below -10° C. After further 15 minutes at -10° to 0° C., the white precipitate was collected by filtration, washed with diethyl ether (4×250 ml) and dried to give 56 g (78%) of the title compound; mp 235°-237° C. (ethanol-water 1:1 ); δH (250 MHz, DMSO-d6) 10.50 (3H, br s, --N+H3), 9.10 (1H, br s, --NH--), 7.71 (2H, d, J=8.8 Hz, Ar--H), 7.03 (2H, d, J=8.8 Hz, Ar--H); m/z (CI) 132 (M+ -1).

Provenance & Evidence