Ammonia → 5-(5-nitrofuran-2-yl)-1H-pyrazole-4-carbaldehyde

Participants

Reaction Steps

Add 54 ml of concentrated ammonia solution dropwise to a suspension of 95.5 g of 1-methoxycarbonyl-3-(5-nitro-2-furyl)pyrazole-4-carboxaldehyde-ethyleneacetal in 750 ml of dioxan. Stir the resulting admixture for 12 minutes. Then add thereto 160 ml of 2N hydrochloric acid to adjust its pH to 1. Stir the thus-acidified product for 30 minutes before diluting it with 2000 ml of water. Allow the resulting precipitate to stand overnight in a cooling cupboard to obtain a quantitative yield of 3-(5-nitro-2-furyl)-1H-pyrazole-4-carboxaldehyde with a melting point of 184° to 186° C.

Provenance & Evidence