Ammonia → 1-(4-Amino-3-methylphenyl)-5-iodo-2,4-dimethylimidazole

Participants

Reaction Conditions

Reaction Steps

Silver sulphate (21.8 g) and crushed iodine (35.5 g) were added portionwise to a stirred solution of 1-(4-amino-3-methylphenyl)-2,4-dimethylimidazole (25.4 g) in sulphuric acid (100 cm3) cooled to -10°. After heating at 55° C. for 2 hours, the cooled mixture was poured onto ice (500 g). The mixture was cautiously adjusted to pH8 by addition of concentrated ammonia solution (S.G. 0.880) and extracted with chloroform (2×500 cm3). The organic extracts were combined, filtered through "Arbocel" (silica) [Trade Mark], and washed with saturated sodium thiosulphate solution (200 cm3). The organic solution was dried (MgSO4) and evaporated in vacuo to give a residue which, on trituration with ether, gave the title compound (32.25 g) as a crude solid which was used without further purification in Preparation 22.

Provenance & Evidence