1,8-Diazabicyclo(5.4.0)undec-7-ene → methyl (E) 3-[2-n-butyl-1-[(2-chlorophenyl)methyl]-1H-imidazol-5-yl]-(2-thienyl)methyl-2-propenoate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 3-acetoxy-3-[2-n-butyl-1-(2-chlorophenyl)methyl-1H-imidazol-5-yl]-2-[(2-thienyl)methyl]propanoate (4.36 g, 8.92 mmol) in dry toluene (80 mL) was treated with 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) (3.2 mL, 21.4 mmol), and the resulting solution was heated at 80° C. under argon for 3 hours. The solvent was evaporated, the residue triturated with ether and activated charcoal was added. After filtration, the filtrate was concentrated to 6.29 g of an oil that was chromatographed over silica gel with 65:35 hexane/ethyl acetate to give 2.89 g (76%) of methyl (E)-3-[2-n-butyl-1-[(2-chlorophenyl)methyl]-1H-imidazol-5-yl]-2-(2-thienyl)methyl-2-propenoate whose NMR and TLC (50% ethyl acetate in hexane on silica gel) were identical to the product prepared by Method A.

Provenance & Evidence