Tributylphosphine → 4'-[(6-ethyl-2,4-dioxo-3,4-dihydrothieno[2,3-d]pyrimidin-1(2H)-yl)methyl]-3'-methoxybiphenyl-2-carbonitrile

Participants

Reaction Steps

A mixture of 3-(2,4-dimethoxybenzyl)-6-ethylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (2 g), 4′-(hydroxymethyl)-3′-methoxybiphenyl-2-carbonitrile (1.7 g), 1,1′-(azodicarbonyl)dipiperidine (2.2 g), tributylphosphine (2.2 mL) and tetrahydrofuran (4 mL) was stirred at room temperature overnight. The reaction mixture was diluted with ethyl acetate, washed successively with 5% aqueous potassium hydrogensulfate solution and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure. The obtained residue was dissolved in trifluoroacetic acid (15 mL), and the mixture was stirred at 50° C. for 2 hr. The reaction mixture was concentrated under reduced pressure. To the obtained residue was added ethyl acetate, and insoluble material was filtered off. The filtrate was concentrated and recrystallized from diethyl ether to give the title compound as a colorless solid (1.9 g, 80%).

Provenance & Evidence