Indiana 47721. Received August 3, 1984 m-and p-aminobenzoic acids were converted to the title compounds by sequential use of ClCH, COCl, SOCl,, glycine methyl or ethyl ester, AcSK, and hydrolysis. The title compounds and a number of salts were compared for mucolytic activity, toxicity, stability, and hygroscopicity. When compared to N-acetyl-L- cysteine (NAC), the compounds exhibit several times the in vitro mycolytic activity of NAC ...