3-Chloro-2-butanone → 8-Amino-2,3-dimethylimidazo[1,2-a]pyridine-6-carboxamide

Participants

Reaction Conditions

Reaction Steps

NaBr (27.0 g; 0.259 mol; 1.33 equiv) was suspended in cyclohexanone (220 mL) and 3-chloro-2-butanone (25.7 mL; 0.242 mol; 1.24 equiv) was added in one portion. The mixture was heated to 80° C. and stirred for 3 h. The mixture was cooled to 50° C., the white solid was filtered off and washed with cyclohexanone (60 mL). 5,6-Diamino-nicotinamide (30 g; 0.1946 mol; 1.0 equiv) was added to the filtrate and the mixture was heated to 100° C. for 4 h, after which 98% conversion was determined by HPLC. The reaction mixture was cooled to 20° C., stirring was continued for 2 h at 20° C. The solid was filtered off, washed with TBME (220 mL) and dried to yield 46.6 g of the title compound. Yield: 73%.

Provenance & Evidence