Cesium carbonate → 2-tert-Butoxycarbonylmethyl-5-nitro-2H-pyrazole-3-carboxylic acid methyl ester

Participants

Reaction Steps

To a stirring mixture of 5-nitro-2H-pyrazole-3-carboxylic acid methyl ester (3.5 gm, 20.5 mmol) dissolved in 150 ml of acetone was added cesium carbonate (8.01 gm, 24.6 mmol) followed by the addition of tert-butyl bromoacetate (3.61 ml). After 5 hours the solids were filtered and the mixture chromatographed on silica gel using 10% ethyl acetate/hexanes as the eluent to obtain 4.16 gm of pure title product. ESI M+1=286.

Provenance & Evidence