反应详情

10 ml of ether and then 0.85 g (0.012 mol) of sodium nitrite in 10 ml of water are added to 2.7 g (0.01 mol) of 5-hydrazino-4-cyano-1-(2,4-dichlorophenyl)-pyrazole in a solution of 1.9 ml of concentrated hydrochloric acid in 10 ml of water at 0° C. When the addition has ended, a further 20 ml of water and 30 ml of ether are added, the mixture is filtered, the ether phase is separated off, dried over calcium chloride and concentrated in vacuo and the oil thus obtainable is purified by chromatography (silica gel; mobile phase: methylene chloride/acetone 9:1). 1.2 g (43% of theory) of 5-azido-4-cyano-1-(2,4-dichlorophenyl)-pyrazole are obtained as an oil.

1. additionWhen the addition
2. filtrationthe mixture is filtered
3. customthe ether phase is separated off
4. dry with materialdried over calcium chloride
5. concentrationconcentrated in vacuo
6. customthe oil thus obtainable is purified by chromatography (silica gel; mobile phase: methylene chloride/acetone 9:1)