反应详情

To a suspension of 9.1 g of 1-methoxycarbonyl-3-(5-nitro-2-furyl)pyrazole-4 -carboxaldehyde in 80 ml of dioxan add dropwise at 5° to 8° C 33.4 ml of concentrated ammonia solution. Stirr the resulting admixture for 15 minutes before acidifying it with 2N hydrochloric acid to a pH value of 2. Distill off the greater part of the dioxan in vacuo. Mix the residue with 100 ml of water. Draw off the precipitate and wash it with water to obtain 3-(5-nitro-2-furyl)-1H-pyrazole-4-carboxaldehyde [melting point: 179° to 185° C] with a yield of 78%.

1. distillationDistill off the greater part of the dioxan in vacuo
2. additionMix the residue with 100 ml of water
3. washwash it with water