Hydrazine hydrate (1:1) → 9-Fluoro-1,2,4-triazolo[1,5-c]quinazoline

Participants

Reaction Conditions

Reaction Steps

3. 2.9 g of crude 6-fluoro-3H-quinazoline-4-thione are suspended in 75 ml of tetrahydrofuran. 7.9 ml of hydrazine hydrate are then added at room temperature while stirring. A solution results for a short time after about 15 min., then a precipitate separates. The mixture is stirred at room temperature for 3 h., 75 ml of methyl orthoformate are then added thereto and the tetrahydrofuran is distilled off. The residual suspension is stirred at room temperature for 3 h. The reaction solution is evaporated in a vacuum. The residue is taken up in 300 ml of water, stirred at room temperature for 1 h. and then cooled to 15° C. The crystals are filtered off and dried in a vacuum, 2.9 g of crude product are obtained. 2.4 g of 9-fluoro-1,2,4-triazolo[1,5-c]quinazoline of m.p. 193°-195° C. are obtained after recrystallization from ethanol.

Provenance & Evidence