(Methoxycarbonylsulfamoyl)triethylammonium hydroxide → HCID 54469685, compound

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Reaction Steps

A solution of 14.0 g (0.0356 mol) of methyl (S)-2-(7-chloro-5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a][1,4]-benzodiazepin-3-ylcarbonylamino)-3-hydroxy-propionate in 250 ml of tetrahydrofuran was treated while gassing with argon with 9.3 g (0.0392 mol) of methoxycarbonylsulphamoyl-triethylammonium hydroxide internal salt (Burgess reagent) according to the method described in Tert. Letters 1992, 33, 907. The mixture was boiled at reflux for 3 1/2 hrs. and completely freed from the solvents. The residue was partitioned between dichloromethane and water, extracted and chromatographed over silica gel with ethyl acetate/ethanol 19:1 as the eluent. There were obtained 6.80 g (51%) of methyl (S)-2-(7-chloro-5-methyl-6-oxo-5,6-dihydro-4H-imidazo[l,5-a][1,4]benzodiazepin-3-yl)-4,5-dihydrooxazole-4-carboxylate as white crystals; m.p. 216°-218°.

Provenance & Evidence