Benzoic Acid → HCID 67848917, compound

Participants

Reaction Steps

A solution of 2-[(2-chlorophenyl)-methyl]amino-3-nitrobenzoic acid (15.62 g, 0.051 mol) in pyridine (125 mL) was stirred with valeryl chloride (15.37 g, 0.127 mol) at 52° C. for 18 hours under argon. The usual workup gave the crude 2-[(2-chlorophenyl)methyl-N-valeryl]-amino-3-nitrobenzoic acid which was not purified. This benzoic acid (51 mmol) was dissolved in tetrahydrofuran (250 mL) and 5% sodium bicarbonate solution (250 mL) was added to give a pH of 7.41. Sodium hydrosulfite (7 times 15 g portions) was added over 3 hours with the pH being adjusted to 7.1 with solid sodium bicarbonate. The mixture was filtered, some ether was added and the organic layer was washed with brine, stirred over magnesium sulfate, filtered and concentrated to a slurry. This crude aminobenzoic acid (23.9 g) was dissolved in a mixture of acetic acid (120 mL) and concentrated hydrochloric acid (40 mL) and heated on a steam bath for 1.5 hours. The solvents were removed in vacuo, and ice water was added to the residue. The precipitated crystals were filtered, washed with water and dried to provide 12.04 g of crude product. Crystallization from methanol gave 9.1 g of 2-n-butyl-1-(2-chlorophenyl)-methyl-1H-benzimidazole-7-carboxylic acid; mp 253°-255° C.

Provenance & Evidence