Methyl 4-aminobenzoate → Methyl 4-(3,5-dichloro-4-(cyclopentyloxy)benzamido)benzoate

Participants

Reaction Steps

A solution of 3,5-dichloro-4-(cyclopentyloxy)benzoic acid (3) (100 mg, 363 μmol) in DCM (5 mL), cooled to 0° C., was treated with oxalyl chloride (63.6 μL, 727 μmol), followed by a drop of DMF. The resultant mixture was stirred for 1 h at RT. The solvent was evaporated in vacuo and the residue dissolved in DCM (5 mL), and then treated with a solution of methyl 4-aminobenzoate (54.9 mg, 363 μmol) and DIPEA (190 μL, 1.09 mmol) in DCM (5 mL). The reaction mixture was stirred for 12 h at RT and then partitioned between DCM (20 mL) and aqueous HCl (20 mL, 1 M). The phases were separated and the organic phase was washed successively with water (2×20 mL), and brine (20 mL), dried over MgSO4, filtered and then the solvent was removed in vacuo. The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane) to afford methyl 4-(3,5-dichloro-4-(cyclopentyloxy)benzamido)benzoate (AAA-002) (30 mg, 20%): m/z 406 (M−H)− (ES−). NMR (400 MHz, CDCl3) δ: 8.06 (2H, d), 7.85 (1H, br s), 7.82 (2H, s), 7.71 (2H, d), 5.05 (1H, m), 3.92 (3H, s), 2.10-1.90 (4H, m), 1.85-1.70 (2H, m), 1.70-1.60 (2H, m).

Provenance & Evidence