2-n-Propyl-4-(2-aminoethyl)-1-[2'-(t-butoxycarbonyl)biphenyl-4-yl]methylimidazole → Ethyl 2-n-propyl-3-[2'-(t-butoxycarbonyl)biphenyl-4-yl]methyl-4,5,6,7-tetrahydroimidazo[4,5-c]pyridine-4-carboxylate oxalate

Participants

Reaction Steps

To a mixture of 2-n-propyl-4-(2-aminoethyl)-1-[2'-(t-butoxycarbonyl)biphenyl-4-yl]methylimidazole (10.0 g) and tetrahydrofuran (100 ml) is added a solution of ethyl glyoxylate hydrate (2.90 g) in tetrahydrofuran at room temperature. The reaction mixture is stirred overnight, refluxed for 30 minutes, and evaporated. The residue is dissolved in chloroform and the solution is washed with 2% hydrochloric acid solution, a saturated sodium hydrogen carbonate solution and brine. The organic layer is dried and evaporated. The crude product is crystallized with oxalic acid from ethanol-ether to give ethyl 2-n-propyl-3-[2'-(t-butoxycarbonyl)biphenyl-4-yl]methyl-4,5,6,7-tetrahydroimidazo[4,5-c]pyridine-4-carboxylate oxalate (8.45 g).

Provenance & Evidence