Hydrochloric Acid → Ethyl 2-hydroxy-3-methyl-2-[6-{[4-(trifluoromethoxy)phenyl]sulfonyl}-2-(trifluoromethyl)-6,11-dihydro-5H-pyrido[2,3-b][1,5]benzodiazepin-8-yl]butanoate

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Reaction Steps

To a solution of 8-iodo-6-{[4-(trifluoromethoxy)phenyl]sulfonyl}-2-(trifluoromethyl)-6,11-dihydro-5H-pyrido[2,3-b][1,5]benzodiazepine (787 mg, 1.28 mmol, intermediate 61) in 2 ml of THF was added a solution of isopropyl magnesium chloride (5.12 ml, 10.24 mmol) in THF (2M) at 0° C. and stirred for 30 min. Then the reaction mixture was added to a solution of diethyl oxalate (4.34 ml, 32 mmol) in 8 mL of toluene and stirred for 30 min. at 0° C. Then the reaction mixture was poured into 3.5 mL of 2 N HCl and 5 mL of ice-water, and the pH was adjusted to pH=7-8 with aqueous NaHCO3. The mixture was extracted with ethyl acetate (3×20 ml) and dried with Na2SO4. The combined organic layers were evaporated under reduced pressure. The resulting residue was purified by column chromatography on silica gel, eluting with hexane/ethyl acetate (4/1-3/1) to give title compound 509; Mass Spectrum: m/e=634 (M+1). Further elution of the column afforded the title compound 510; Mass Spectrum: m/e=590 (M+1).

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