N,N-Dimethylaniline → 5,7-Dichloro-3-(2-chlorobenzyl)-1-(4-methoxybenzyl)-1H-benzo[e][1,4]diazepin-2(3H)-one

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Reaction Conditions

Reaction Steps

7-Chloro-3-(2-chlorobenzyl)-1-(4-methoxybenzyl)-3,4-dihydro-1H-benzo[e][1,4]diazepine-2,5-dione (0.65 g, 1.43 mmol) was suspended in anhydrous toluene (10 mL) under a nitrogen atmosphere. N,N-Dimethylaniline (0.36 mL, 2.9 mmol) was added followed by phosphorus oxychloride (0.20 mL, 2.1 mmol) and the mixture was heated at 90° C. for 4 hours. After cooling to ambient temperature, the mixture was diluted with 40 mL of ethyl acetate:hexanes (1:2), washed with ice water (10 mL), ice cold 1 M hydrogen chloride (2×10 mL), and brine, then dried with sodium sulfate, decanted and concentrated in vacuo. The residue was redissolved in a small amount of ethyl acetate, then poured onto a silica plug. The product was eluted with 100 mL of ethyl acetate:hexanes (1:2) to yield (E)-5,7-dichloro-3-(2-chlorobenzyl)-1-(4-methoxybenzyl)-1H-benzo[e][1,4]diazepin-2(3H)-one (680 mg, 100%) which was used without further purification.

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