Dichloromethane → HCID 22961979, compound

Participants

Reaction Steps

Triethylamine (4.7 ml) and chlorotriphenylmethane (9.37 g) were added to a mixture of methyl 4,5,6,7-tetrahydro-1H-benzimidazole-5-carboxylate (6.73 g) and dichloromethane (70 ml), followed by stirring at room temperature overnight. Water was added to the reaction solution, followed by extraction with dichloromethane, the organic layer was concentrated, and the resulting residue was purified by silica gel column chromatography (chloroform) to obtain a mixture (10.13 g) of methyl 1-trityl-4,5,6,7-tetrahydro-1H-benzimidazole-5-carboxylate and methyl 1-trityl-4,5,6,7-tetrahydro-1H-benzimidazole-6-carboxylate. Methanol (50 ml), water (20 ml) and sodium hydroxide (4.78 g) were added to the obtained mixture, followed by heating to reflux overnight. The reaction solution was concentrated, water and concentrated hydrochloric acid (8 ml) were added to the residue, and the precipitated solid was collected by filtration, washed with water and acetone and dried under reduced pressure to obtain a mixture (7.07 g) of 1-trityl-4,5,6,7-tetrahydro-1H-benzimidazole-5-carboxylic acid and 1-trityl-4,5,6,7-tetrahydro-1H-benzimidazole-6-carboxylic acid, as a colorless solid.

Provenance & Evidence