Acetic Acid → 6-Bromopyrazolo[1,5-a]pyrimidine-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl 5-amino-1H-pyrazole-4-carboxylate (2 g, 12.89 mmol) and sodium hydroxide (19.34 mL, 38.7 mmol) (aqueous, 2M) in ethanol (30 mL) was heated at 80° C. overnight. The reaction mixture was concentrated in vacuo to give a crude mixture of carboxylate and sodium hydroxide. The crude mixture was dissolved in ethanol (4 mL) and acetic acid (14 mL, 245 mmol). Whilst stirring the mixture, bromomalonaldehyde (1.947 g, 12.90 mmol) was added and then the mixture heated to 70° C. for 1 h. The reaction mixture was allowed to cool and the precipitate was filtered and washed with ethanol. The solid product was dried in a vacuum oven to give the title compound (1.589 g).

Provenance & Evidence