Tetrahydrofuran → 9,10-Dihydro-4-methyl-4H-thieno[3,4-b][1,5]benzodiazepine

Participants

Reaction Steps

A mixture comprising 4 g. of 4,9-dihydro-4-methyl-10H-thieno[3,4-b][1,5]benzodiazepin-10-one [U.S. Pat. No. 3,953,430 (Example 2)] in 75 ml. of tetrahydrofuran is combined with 2 g. of lithium aluminum hydride in 50 ml. of tetrahydrofuran and refluxed under nitrogen with stirring for 10 hours. A 2 ml. portion of water is carefully added dropwise with cooling followed by 2 ml. of 15% sodium hydroxide and 6 ml. of water. The mixture is filtered and the precipitate is washed thoroughly with ether. The filtrate and washings are combined, dried over sodium sulfate, filtered and concentrated to a semi-crystalline brown oil. The product is triturated with hexane producing a tan crystalline solid. This solid is recovered, washed thoroughly with hexane and dried. This crystalline material is purified by column chromatography (alumina activity II), eluting with methylene chloride:hexane (50:50). Evaporation of the solvents yields a solid which is triturated with hexane and washed with ether, giving the desired product as pale blue crystals, mp. 125°-127° C.

Provenance & Evidence