Sulfuric Acid → 3-((Imino((2,2,2-trifluoroethyl)amino)methyl)amino)1H-pyrazole-1-pentamide

Participants

Reaction Steps

5-[3-(2-[2,2,2-Trifluoroethyl]guanidino)pyrazol-1-yl]valeronitrile (13 g.), was added over 10 minutes to concentrated sulphuric acid (65 ml.) with stirring. The resulting solution was kept at 20° for 18 hours then diluted with ice (300 ml.) and basified to pH 9 with 10.8N sodium hydroxide. The mixture was extracted with EtOAc (3×200 ml.) and the extract was dried (MgSO4) and evaporated in vacuo to an oil which crystallised. The crude material was recrystallised from EtOAc to give 5-[3-(2-[2,2,2-trifluoroethyl]guanidino)pyrazol-1-yl]valeramide, m.p. 130°. The maleic acid salt was prepared in acetone, m.p. 183°-184°.

Provenance & Evidence