methyl 4-(6,6-dimethyl-4-oxo-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carboxylate 以
四氢呋喃 、
水 为溶剂,
以62%的产率得到4-(6,6-dimethyl-4-oxo-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carboxylic acid