Hydrochloric Acid → 1-(3-benzyl-1,5-dihydro-5-thioxo-4H-1,2,4-triazol-4-yl)-2-propanone
Reaction equation
C1O[C:4]([CH3:19])([CH2:5][N:6]2[C:10](=[S:11])[NH:9][N:8]=[C:7]2[CH2:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[O:3]C1.Cl>C(O)C>[CH2:12]([C:7]1[N:6]([CH2:5][C:4](=[O:3])[CH3:19])[C:10](=[S:11])[NH:9][N:8]=1)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1Participants
4
Procedure
To 10 ml of ethanol was added 1.1 g of the 1-(3-benzyl-1,5-dihydro-5-thioxo-4H-1,2,4-triazol-4-yl)-2-propanone ethylenacetal obtained in Reference Example 5, followed by addition of 5.0 ml of 2N-hydrochloric acid. The mixture was refluxed for 40 minutes and, then, concentrated to half the original volume. To the concentrate was added water and the resultant precipitate was recovered by filtration. This procedure provided 1-(3-benzyl-1,5-dihydro-5-thioxo-4H-1,2,4-triazol-4-yl)-2-propanone as crystals. Recrystallization from ethyl acetate gave colorless needles melting at 163°-165° C.