1,8-Diazabicyclo(5.4.0)undec-7-ene → HCID 19787203, compound

Participants

Reaction Steps

To a solution of DBU (5.2 g) in toluene (50 ml) was added dropwise a solution of 3-(2-chlorobenzoyl)-2-ethoxycarbonylacetylamino-5-ethylthiophene (6.5 g) in toluene (30 ml) over one hour with stirring under reflux. After refluxing for 7 hours, the mixture was washed with water and dried over MgSO4, and then the solvent was distilled off. The residue was chromatographed on a silica gel column and eluted with hexane-acetone (5:1). The solvent was distilled off and hexane was added to obtain ethyl 4-(2-chlorophenyl)-6,7-dihydro-2-ethyl-6-oxothieno[2,3-b]pyridine-5-carboxylate as crystals (2.05 g, 33.1%). The crystals were recrystallized from ethanol to obtain light yellow prisms, mp: 126°-127° C.

Provenance & Evidence