3,5-isoxazoledicarboxylic acid, 4,5-dihydro-, 3-ethyl ester 3-(ethoxycarbonyl)-4,5-dihydroisoxazole-5-carboxylic acid InChI=1/C7H9NO5/c1-2-12-7(11)4-3-5(6(9)10)13-8-4/h5H,2-3H2,1H3,(H,9,10