A mixture of 7-aminosalicylic acid (102 mg, 0.67 mmol) with NaOH (27 mg, 0.67 mmol) in water (6 mL) was stirred at room temperature for 10 min until completely dissolved, using 7-aminosalicylic acid (102 mg, 0.67 mmol) as starting material. Na2CO3 (59 mg, 0.5561 mmol) was then added and the mixture was cooled to 0 °C. A solution of THF (2 mL) of 2-chloro-2-oxoethyl-4-methylbenzenesulfonate (200 mg, 0.8044 mmol) was quickly added, and the reaction system was gradually warmed to room temperature and stirred continuously for 2 hours. Upon completion of the reaction, the mixture was transferred to a partition funnel containing ether for phase separation. After the aqueous phase was washed with another portion of ether, the pH was adjusted to 1 by dropwise addition of 1N HCl solution and the product was subsequently extracted with ethyl acetate. The ethyl acetate phase was washed twice sequentially with 1N HCl solution, dried over Na2SO4, filtered and concentrated under reduced pressure to remove the solvent. The resulting light yellow solid was ground with chloroform to afford the target product 2-hydroxy-4-(2-(tolylsulfonyloxy)acetylamino)benzoic acid (155 mg, 63% yield) in white powder form. The product characterization data were as follows: 1H NMR (400 MHz, DMSO) δ 2.37 (3H, s, Me), 4.68 (2H, s, CH2), 6.93 (1H, d, J = 7.4 Hz, ArH), 7.17 (1H, s, ArH), 7.46 (2H, d, J = 6.8 Hz, ArH), 7.69 (1H, d, J = 7.4 Hz, ArH), 7.81 (2H, d, J = 6.8 Hz, ArH), 10.32 (1H, s, NH); 13C NMR (100.6 MHz, DMSO) δ 21.8, 68.0, 107.0, 110.7, 128.5, 130.9, 131.7, 132.7, 144.5, 146.0, 162.8, 164.8, 164.0, 166.0, 162.8, 164.8, 164.0, 166.0, 166.0, 164.0 162.8, 164.5, 172.2; MS (ES+) m/z 366.0 ([M + H]+, 100%), 388.0 ([M + Na]+, 50%); no signal detected in the negative ion mode.
![Acetyl chloride, 2-[[(4-methylphenyl)sulfonyl]oxy]-](/CAS/20200611/GIF/54150-49-1.gif)
