Ethyl Acetate → benzyl 9-chloro-5-(o-fluorophenyl)-2,3-dihydro-1,3,3-trimethyl-2-oxo-1H-1,4-benzodiazepine-7-carbamate

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Reaction Steps

12 g (0.035 mol) of 7-amino-9-chloro-5-(o-fluorophenyl)-1,3-dihydro-1,3,3-trimethyl-2H-1,4-benzodiazepin-2-one are dissolved in 360 ml of dry tetrahydrofuran, treated with 10 g of ground sodium bicarbonate and 8 ml of chloroformic acid benzyl ester and stirred at room temperature for 31/2 hours. The mixture is treated with ethyl acetate and water, and separated aqueous phase is extracted twice with ethyl acetate and the combined organic extracts are dried and evaporated. The residue is chromatographed on 600 g of silica gel with methylene chloride/ethyl acetate (20:1 ) as the elution agent. From ether there is obtained benzyl 9-chloro-5-(o-fluorophenyl)-2,3-dihydro-1,3,3-trimethyl-2-oxo-1H-1,4-benzodiazepine-7-carbamate of melting point 212°.

Provenance & Evidence