Bromide ion → methyl 2-(5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a]thieno[2,3-f][1,4]-diazepin-3-yl)-oxazole-4-carboxylate

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Reaction Steps

A solution of 5.92 g (0.0171 mol) of methyl (S)-2-(5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a]thieno[2,3-f][1,4]-diazepin-3-yl)-4,5-dihydro-oxazole-4-carboxylate in 300 ml of benzene was treated with 2.69 g (0.0188 mol) of copperl bromide and 4.97 ml (0.0256 mol) of tert-butyl perbenzoate according to the method described in Tetr. Letters 1994, 35, 2481. The mixture was boiled at reflux for 1 hr., cooled and treated with 100 ml of water. The mixture was filtered, extracted with benzene and chromatographed over silica gel with ethyl acetate as the eluent. There were obtained 1.48 g (25%) of methyl 2-(5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a]thieno[2,3-f][1,4]-diazepin-3-yl)-oxazole-4-carboxylate as a yellowish solid. An analytical sample was recrystallized from hot ethyl acetate and gave white crystals; m.p. 254°-255°.

Provenance & Evidence