Some comments on the synthesis of 3‐aminotoluene‐5‐sulfonic acid and 2‐aminotoluene‐3‐sulfonic acid.Sulfonation of 3‐nitrotoluene (5) yields predominantly the unsymetrical isomer 5‐nitrotoluene‐2‐sulfonic acid (7), and lesser amounts of 5‐nitrotoluene‐3‐sulfonic acid (6), previously reported as the major product. The desired 5‐aminotoluene‐3‐sulfonic acid (3) was synthesized in preparative amounts from 6‐aminotoluene‐3‐sulfonic acid (4)viathe following sequence of reactions: diazotation andSandmeyerreplacement of 6‐chlorotoluene‐3‐sulfonic acid (13), nitration of the sulfonyl chloride14under suitable conditions to give isomer free 6‐chloro‐5‐nitrotoluene‐3‐sulfonyl chloride (15), hydrolysis to the sulfonic acid16and finally, simultaneous hydrogenolysis and reduction to3. The isomeric7was unequivocally prepared from 2‐amino‐5‐nitrotoluene (9)viatwo routes: (1) diazotation,Sandmeyerthiocyanatation to 5‐nitro‐2‐thiocyanatotoluene (10), Na2S reduction to the di(2‐methyl‐4‐nitro‐phenyl)‐disulfide (11), treatment with nitric acid and chlorine to give 5‐nitrotoluene‐2‐sulfonyl chloride (12) and finally alkaline hydrolysis to7; (2)Meerwein'sSO2treatment of the diazonium salt derived from9leads directly to12and thence to7.2‐Aminotoluene‐3‐sulfonic acid (1) was prepared from the key intermediate 3‐amino‐2‐nitrotoluene (18)viathe same two routes used to prepare7from9. Both reaction sequences provided 2‐nitrotoluene‐3‐sulfonly chloride, the hydrolysis product of which was reduced to1. Intermediate18was prepared in the following four steps fromm‐toluic acid (19): nitration to the 2‐nitroderivative (2