Diisopropylethylamine → (2'-methoxy-biphenyl-4-yl)-(5H,11H-pyrrolo[2,1-c][1,4]benzodiazepin-10-yl)-methanone

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Reaction Steps

A suspension of 2′-methoxy-[1,1′-biphenyl]-4-carboxylic acid of Step B (1.0 g, 4.38 mmol) in thionyl chloride (6 mL) was heated at reflux for 30 min. After cooling, the thionyl chloride was removed in vacuo. The residue was dissolved in toluene and concentrated in vacuo to give the crude acid chloride as a yellow solid. The latter was then dissolved in dichloromethane (10 mL) and the solution was slowly added to a solution of 10,11-dihydro-5H-pyrrolo [2,1-c][1,4]benzodiazepine (0.97 g, 5.27 mmol) and N,N-diisopropylethyl amine (1.6 mL, 9.19 mmol) in dichloromethane (30 mL). After stirring for 2 hours, the reaction was quenched with water. The organic layer was washed with 1 N hydrochloric acid, 1 N sodium hydroxide and brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give a yellow foam. Purification of the residue by flash chromatography using a solvent gradient from 15% to 25% of ethyl acetate in hexane provided the title compound as a white foam which was crystallized by sonication from ethyl acetate/hexane (1.4 g, 81.0%) to give a white solid m.p. 145-147° C.

Provenance & Evidence