Styrene → 4-(1-methyl-piperidin-4-yloxy)-8-phenethyl-2-phenyl-9,10-dihydro-4H-3,10a-diaza-benzo[f]azulene

Participants

Reaction Conditions

Reaction Steps

To a solution of 8-bromo-4-(1-methyl-piperidin-4-yloxy)-2-phenyl-9,10-dihydro-4H-3,10a-diaza-benzo[f]azulene (example 231) (276 mg, 0, 61 mmole) in anhydrous dimethylformamide (5 mL) in a screw-capped vial are added n-tetrabutylammonium bromide (196 mg, 0, 61 mmole), lithium chloride (26 mg, 0, 61 mmole), palladium(II) acetate (27 mg, 0, 12 mmole), styrene (174 μL, 1, 5 mmole) and potassium carbonate (420 mg, 3, 0 mmoles). The vial is evacuated and filled with argon. The reaction mixture is stirred at 95° C. for 20 hours. Water and diethyl ether are added to the reaction mixture. The organic phase is washed with water, dried over magnesium sulphate, filtered and concentrated under reduced pressure. To the residue are added methanol (10 mL), 10% Pd/C (150 mg) and ammonium formate (3 g). After reflux for 1.5 hours the mixture is filtered on a celite pad, concentrated under reduced pressure, diluted with ethyl acetate, washed with water, dried over magnesium sulphate and the solvent was removed under reduced pressure. The residue is purified by preparative HPLC-MS (Waters AutoPurification HPLC/MS System, Sunfire Prep C18 5 μm OBD 30×150 mm column, eluents: water/0.1% formic acid (A) and acetonitrile/0.1% formic acid (B), focus gradient from 23% (B) to 33% (B) in 10 minutes) to afford 4-(1-methyl-piperidin-4-yloxy)-8-phenethyl-2-phenyl-9,10-dihydro-4H-3,10a-diaza-benzo[f]azulene melting at 67° C.

Provenance & Evidence