4-Aminobenzoic Acid → HCID 24785947, compound

Participants

Reaction Steps

A mixture of p-aminobenzoic acid (43 mg, 0.31 mmol) and NaOH (12.5 mg, 0.31 mmol) in water (3 ml) was stirred at room temperature for 10 min until all of the solid material had dissolved. Na2CO3 (27 mg, 0.258 mmol) was then added and the mixture cooled to 0° C. A suspension of sulfonyl chloride 18 (106 mg, 0.341 mmol) in THF (1 ml) was injected rapidly and the resulting solution allowed to warm to room temperature and stirred for 2 h. Then reaction mixture was poured into a separating funnel containing diethyl ether. The phases were separated and the aqueous phase washed with a further portion of diethyl ether. The aqueous phase was acidified to pH 1 by addition of 1N HCl solution and the product extracted into ethyl acetate. The ethyl acetate was washed twice with 1N HCl solution and the organic phase was dried (Na2SO4), filtered and the solvent removed in vacuo. The resulting solid was recrystallized from hexane/ethyl acetate affording acid 20 as an off white powder (81 mg, 64%). δH (400 MHz, DMSO) 4.79 (2H, s, CH2), 7.45-7.70 (9H, m, ArH), 7.86-8.03 (4H, m, ArH), 10.43 (1H, NH); δc (100.6 MHz, DMSO) 68.2, 119.4, 126.5, 127.9, 128.6, 129.2, 129.6, 129.8, 131.1, 134.3, 138.7, 142.7, 146.7, 164.4, 167.5; MS (ES+) 411.7 (100%, [M+H]+).

Provenance & Evidence