2-Butynoic acid → 1-[1-(2,6-difluorophenyl)ethyl]-1H-1,2,3-triazole-4-carboxylic acid
Reaction equation
[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1[CH:9]([N:11]=[N+:12]=[N-:13])[CH3:10].[C:14]([C:17]([OH:19])=[O:18])#[C:15]C>C1(C)C=CC=CC=1>[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1[CH:9]([N:11]1[CH:15]=[C:14]([C:17]([OH:19])=[O:18])[N:13]=[N:12]1)[CH3:10]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
6.5 g (35 millimoles) of 1-(2,6-difluorophenyl)ethyl azide and 2.45 g (35 millimoles) of propinecarboxylic acid in 50 ml of toluene are heated for 24 hours to 60°-70° C. The cooled reaction mixture is extracted with 100 ml of 1N sodium hydroxide solution and the extract is acidified with hydrochloric acid to give 1-[1-(2,6-difluorophenyl)ethyl-1H-1,2,3-triazole-4-carboxylic acid with a melting point of 135°-138° C. (dec.). 7.1 g (26.6 millimoles) of 1-[1-(2,6-difluorophenyl)ethyl]-1H-1,2,3-triazole-4-carboxylic acid, 150 ml of ethanol and 1 ml of sulfuric acid are heated for 10 hours to reflux. Working up gives ethyl 1-[1-(2,6-difluorophenyl)ethyl]-1H-1,2,3-triazole-4-carboxylate with a melting point of 118°-121° C.