copper; potassium carbonate in benzene byproducts: 4-aminosalicylic acid; raegents mixing in benzene, stiriing for 2 h, filtering and evapg.; detected by NMR spectrum and gas chromy.;

copper; potassium carbonate in benzene byproducts: 4-aminosalicylic acid; raegents mixing in benzene, stiriing for 2 h, filtering and evapg.; detected by NMR spectrum and gas chromy.;