p-Toluenesulfonic acid → HCID 19010444, compound

Participants

Reaction Steps

To a mixture of 9,5 parts of 2-hydrazino-5-phenyl-7-trifluoromethyl-3-H-1,4-benzodiazepine prepared in Example 4, 29 parts of ethyl orthoacetate and 150 parts by volume of chloroform, is added dropwise 23 parts of p-toluenesulfonic acid with stirring under ice-cooling below 10° C and then the mixture is stirred at room temperature for 7 hours. After completion of the reaction, the reaction mixture is neutralized with a saturated aqueous solution of sodium bicarbonate and the chloroform layer is separated, washed with water and dried over sodium sulfate. After evaporation of the solvent, the residue is treated with a mixture of benzene and isopropyl ether, whereby 1-methyl-6-phenyl-8-trifluoromethyl-4H-s-triazolo [4,3-a] [1,4] benzodiazepine is yielded as crystals containing benzene of crystallization. Recrystallization from a mixture of benzene and n-hexane yields colorless needless melting at 129° C to 130° C (sintering), 133° C to 134° C (effervescence).

Provenance & Evidence