2-Methyl-1-(3-sulphonatopropyl)naphtho(1,2-d)thiazolium 2-Methyl-3-(3'-sulfopropyl)(1,2-d)naphthothiazolium betaine 3176-77-0 EINECS 221-646-1 Naphtho(1,2-d)thiazolium, 2-methyl-1-(3-sulfopropyl)-, inner salt