p-Toluenesulfonic acid → 4-Cyano-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole-2-carboxylic acid [2-cyclohex-1-enyl-4-(2-methyl-[1,3]dioxolan-2-yl)-phenyl]-amide

Participants

Reaction Steps

A solution of 4-cyano-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole-2-carboxylic acid (4-acetyl-2-cyclohex-1-enyl-phenyl)-amide (as prepared in the previous step, 135 mg, 0.290 mmol), ethanediol (363 mg, 5.80 mmol) and catalytic p-toluenesulfonic acid (PTSA) in 21 mL of benzene were heated at reflux under Dean-Stark conditions for 4 h. The reaction was diluted with EtOAc (25 mL), washed with water (3×20 mL), dried (Na2SO4), and concentrated in vacuo. Purification of the residue using preparative TLC (10% MeOH—CHCl3) afforded 100 mg (68%) of the title compound as a white solid. Mass spectrum (ESI, m/z): Calcd. for C27H36N4O4Si, 509.2 (M+H), found 509.0.

Provenance & Evidence