Hydrochloric Acid → Dimethyl 5-aminoisophthalate

関与物質

反応手順

5-Nitro-1,3-benzenedicarboxylic acid dimethyl ester (95.7 g, 0.4 mol) and 5% Pd/C (8 g) are loaded into a 2 L hydrogenation vessel equipped with a thermometer and a mechanical stirrer, that contains methanol (0.8 L) and 2M HCl (0.3 L; 0.6 mol). The obtained suspension is maintained under mechanical stirring and purged with nitrogen washings, at the end of which the hydrogenation reaction is carried out at a temperature comprised between 45 and 55° C. The reaction is complete in 2 hours. A nitrogen flow is then passed through the reaction vessel to wash out any hydrogen gas, the catalyst is filtered off and the obtained solution is evaporated under vacuum to yield a solid residue. The obtained product is loaded into a 5 L vessel, equipped with a mechanical stirrer, and containing deionized water (3 L) and 34% HCl (0.1 L). The obtained suspension is filtered from the insoluble residue and 2M NaOH is added to the filtrate up to pH 10. The solid product that crystallizes out is recovered by filtration, washed with deionized water and dried under vacuum in the presence of P2O5 yielding the compound of the title (77.0 g; 0.368 mol, yield: 92%).

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