55503-20-3 7-Ethyl-2-methyl-4-oxo-4,7-dihydrothieno(2,3-b)pyridine-5-carboxylic acid Emodhtp Thieno(2,3-b)pyridine-5-carboxylic acid, 7-ethyl-4,7-dihydro-2-methyl-4-oxo-