Acetic Acid → HCID 19374947, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 10.96 g (0,035 mol) of 2-methoxycarbonyl-3-hydroxy-5-tert-butoxycarbonyl-6,7-dihydro-4H-thieno[3,2-c]pyridine (prepared as described in Preparation 6) in 125 mL of tetrahydrofuran were added 8.14 g (0.0535 mol) of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene and 6.55 g (0.053 mol) of 2-bromopropane. The solution was heated at reflux for 4 hours. An additional 3.28 g (0.0266 mol) of 2-bromopropane and 4.07 g (0.0268 mol) of DBU dissolved in 75 mL of DMF were added, and the reaction mixture was stirred at 82° C. for 2.5 hours, cooled to 24° C., and stirred for 3 days. The reaction mixture was added to 550 g of ice water containing 10 mL of glacial acetic acid. The aqueous mixture was extracted four times with 100 mL portions of diethyl ether. The ethereal extracts were combined, washed with saturated aqueous sodium bicarbonate, with water and brine, dried over sodium sulfate, and the solvent was removed by evaporation under reduced pressure to afford 13 g of crystalline 2-methoxycarbonyl-3-isopropoxy-5-tert-butoxycarbonyl-6,7-dihydro-4H-thieno[3,2-c]pyridine, mp 76°-81° C.

Provenance & Evidence