Hydrochloric Acid → 7-(2-Chlorophenyl)-2-methyl-3H-pyrazolo[1,5-a][1,3,5]triazin-4-one

Participants

Reaction Steps

To a pale yellow solution of N-[5-(2-chlorophenyl)-2H-pyrazol-3-yl]-acetamidine (I-1A-1b; 2.04 g, 8.69 mmol) in DMSO (17 mL) was added 1,1′-carbonyldiimidazole (1.53 g, 9.44 mmol), portionwise over 1 minute at room temperature. After stirring for one hour, the reaction was added to stirred 1 M aqueous HCl (17 ml) over 5 minutes. The colorless precipitate that formed was stirred for 2.5 hours and then collected on a course sintered funnel. The solids were washed with water (50 ml) and then dried on the frit under a stream of air using low vacuum to afford I-1A-1c as a colorless solid (2.29 g, quantitative): +APcI MS (M+1) 261.3.

Provenance & Evidence