Hydrochloric Acid → 2-Amino-4-chloro-5-methylbenzoic acid

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Reaction Steps

A mixture of 5-chloro-2-cyano-4-methylaniline (4.0 g,0.024 mol), 30% aqueous KOH solution (56 ml), and 30% hydrogen peroxide (4 ml) was placed in an oil bath preheated to 130° C., then stirred at this temperature for 2 hours (a clear solution had obtained after 1.5 h). The clear solution was then allowed to cool to room temperature, diluted with water (200 ml), and acidified to pH ˜5.50 with 3N HCl, then allowed to stand at room temperature for few hours. The off white solid was collected by filtration, washed with water and dried in vacuo over P2O5 (4.13 g, 93%), mp 212-215° C. 1H-NMR (DMSO-d6) 2.16 (s, 3H, CH3), 6.83, 7.62 (2×s, 2H, 3-H, 6-H), 8.50 (br s, 2H, NH2); MS (FAB, m/z): 188, 186 (M+H)+; FAB-HRMS: measured: 185.0256; calculated for C8H8ClNO2 (M+) 185.0244.

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