Ethyl bromoacetate → 1-Ethoxycarbonylmethyl-2-oxo-1,2,3,5-tetrahydro-benzo[e][1,4]diazepine-4-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

Sodium hydride (152.6 mg, 3.81 mmol, 60% suspension in mineral oil) was washed with hexane (2×2 mL) in a flame dried round bottomed flask under nitrogen atmosphere. To the resulting free floating powder, was added a solution of 2-oxo-1,2,3,5-tetrahydro-benzo[e][1,4]diazepine-4-carboxylic acid tert-butyl ester (500 mg, 1.90 mmol) in dry DMF (10 mL) at 0° C. The reaction mixture was stirred at this temperature for 1 h. Ethyl bromoacetate (0.21 mL, 1.9 mmol) was added at 0° C. and the reaction mixture was allowed to come to r.t. and stirred overnight. After the completion of the reaction as confirmed by TLC, reaction mixture was cooled to 0° C. and saturated solution of ammonium chloride (3 mL) was added dropwise to the reaction mixture. The crude product was extracted with ethylacetate (3×10 mL). The combined organic layers were dried over Na2SO4 and solvents were removed in vacuo to afford 1-ethoxycarbonylmethyl-2-oxo-1,2,3,5-tetrahydro-benzo[e][1,4]diazepine-4-carboxylic acid tert-butyl ester (480 mg, 72%) as a viscous oil which was used as such without any further purification for the next step.

Provenance & Evidence