InChI=1S/C14H16N2O4S/c1-15-12(19)9-6-8-4-3-5-10(18)11(8)16(9)13(20)14(15,7-17)21-2/h3-5,9,17-18H,6-7H2,1-2H3/t9?,14-/m1/s1