Dimethyl Sulfoxide → 4,9-Dihydro-4-(2-dimethylaminoethyl)-9-methyl-10H-thieno[3,4-b] [1,5]benzodiazepin-10-one

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Reaction Steps

A mixture of 0.72 g. of 55% sodium hydride-mineral oil dispersion and 0.60 g. of dimethylaminoethylchloride hydrochloride in 25 ml. of dimethylsulfoxide is stirred at room temperature for 0.5 hours. To the mixture is added 0.46 g. of 4,9-dihydro-9-methyl-10H-thieno[3,4-b][1,5]benzodiazepin-10-one and stirring is continued for 3 hours. The reaction mixture is quenched by dropwise addition of water, diluted with about 200 ml. of water, acidified, filtered, made alkaline with 5N sodium hydroxide and extracted several times with chloroform. The chloroform extracts are dried over magnesium sulfate and concentrated under reduced pressure to give an amber oil. The oil is dissolved in a minimal volume of ethanolic hydrogen chloride solution and diluted with ether to give an oily semi-solid which slowly crystallizes. Recrystallization from ethanol-ether gives tan crystals, m.p. 245°-248° C. (dec.).

Provenance & Evidence