126598-33-2 3-(3,4,5-Trimethoxyphenyl)-7H-1,2,4-triazolo(3,4-b)(1,3,4)thiadiazine-6-carboxylic acid 7H-1,2,4-Triazolo(3,4-b)(1,3,4)thiadiazine-6-carboxylic acid, 3-(3,4,5-trimethoxyphenyl)-