Ethyl 2-chloroacetoacetate → HCID 178469277, compound

Participants

Reaction Steps

A mixture of 1 g of 4-methylthiosemicarbazide (9.51 mmol) and 1.565 g of ethyl-2-chloro-acetoacetate (9.51 mmol) in THF (20 ml) was stirred for 30 min at RT and then heated to reflux for 1 h. The yellow solid that precipitated was filtered off, washed with acetone and then dissolved in hot (95° C.) water. The precipitating sulfur was filtered off, the aqueous solution was cooled to 0° C., vigorously stirred and 5 ml of an aqueous ammonium hydroxide solution (25%) were added. A white precipitate formed and the suspension was stirred for an additional hour at RT. The precipitate was then filtered off and dried to give 1.04 g (60%) of 3-methyl-5-methylamino-1H-pyrazole-4-carboxylic acid ethyl ester as a white solid. MS (ISP) 184.1 (M+H)+.

Provenance & Evidence