5-Amino-3-methylisothiazole monohydrochloride52547-00-9100 % similar 2-Hydroxy-4,6-dimethylpyrimidine hydrochloride34289-60-634 % similar 5-Amino-3-methylisoxazole14678-02-531 % similar 3,3′,5,5′-Tetramethylbenzidine dihydrochloride64285-73-031 % similar