Hydrochloric Acid → HCID 18516448, compound

Participants

Reaction Conditions

Reaction Steps

2-Mercapto-1-methylimidazole (400 mg, 3.50 mMol) was dissolved in anhydrous THF (7.0 mL) under a stream of dry N2. The solution was then cooled to −78° C. and a solution of 2.8 mL of a 2.5 M solution of n-butyllithium in hexanes was then added. After the addition was complete, the reaction mixture was warmed to ambient temperature and stirred at this temperature for 1 hour. The reaction mixture was then cooled to −78° C. and a solution of (4-chloro-benzoyl)-1-methyl-4-[3-(4-trityloxy-but-1-ynyl)-phenyl]-1H-quinolin-2-one in THF (7.0 mL) was added to the mixture. The reaction was warmed to ambient temperature and stirred overnight. The reaction mixture was quenched with saturated aqueous NH4Cl (25 mL) and partitioned between DCM and water. The DCM layer was dried over Na2SO4, filtered and concentrated under vacuum to give a green solid. The green solid was dissolved in 30 mL of acetic acid (AcOH) and the solution was cooled to about 5° C. To this solution was added 2.0 mL of 30% aqueous hydrogen peroxide (H2O2) dropwise. After the addition was complete, the reaction mixture was stirred at ambient temperature for 30 minutes. The reaction mixture was then cooled to 0° C., 200 mL of water was added and the reaction was basified to pH=10 with the slow addition of NaOH. Sodium sulfite was added portionwise until testing with starch-iodine paper showed no H2O2 left. The reaction mixture was partitioned between DCM and water. The DCM layer was dried over Na2SO4, filtered and concentrated under vacuum to give a green solid. The green solid was dissolved in a solution of MeOH/DCM (25:3) to which was added 3 N aqueous HCl (3.0 mL). The solution was then heated to 68° C. and reacted at this temperature for 2 hours. The solution was concentrated under vacuum to a thick sludge and then was partitioned between DCM and 0.01 N aqueous NaOH. The DCM layer was concentrated under vacuum and chromatographed on flash silica gel eluting with a gradient of MeOH/EtOAc/NH4OH (5:95:.01) to MeOH/EtOAc/NH4OH (10:90:.01) to give the titled compound.

Provenance & Evidence