(3-Oxo-3,4-dihydro-2H-benzo[1,4]thiazin-2-yl)-acetic acid3,4-Dihydro-3-oxo-2H-(1,4)-benzothiazin-2-ylacetic acid3,4-二氢-3-氧-2H-(1,4)-苯噻嗪-2-乙酸(3-oxo-3,4-dihydro-2H-1,4-benzothiazin-2-yl)acetic acid3,4-Dihydro-3-oxo-2H-1,4-benzothiazine-2-acetic acid3-Oxo-3,4-dihydro-2H-1,4-benzothiazine-2-acetic acid3,4-二氢-3-氧-2H-1,4-苯噻嗪-2-乙酸2-(3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazin-2-yl)acetic acid