Water → HCID 14771500, compound

Participants

Reaction Steps

A mixture composed of 4.3 g (0.01 mole) of 1-(N,N-dimethylamino)-1propionyl 2-(4-tosyloxybenzenesulfonyl)ethene is heated at reflux for 20 hours in 25 ml of methanol and 10 ml of water in the presence of 2.35 g (0.05 mole) of methylhydrazine. The mixture is allowed to cool to room temperature and then cooled in ice for 1 h. It is evaporated to dryness and 4.85 g of residue are thus obtained which are recrystallized from 250 ml of water and decolorized with 0.8 g of active charcoal. The product is filtered off and allowed to crystallize for 2 hours in ice. It is recrystallized again from 50 ml of dichloroethene. In this manner, 1.15 g of 5-ethyl 4-(4-hydroxybenzenesulfonyl)1-methyl pyrazole is obtained which represents a yield of 43.2%. M.p.: 188.5°-190° C.

Provenance & Evidence