c 6 h 6 o 3 s h 1 h nmr 300 mhz dmso d 6 u03b4 1 2 m 6h 1 6 m 1h 3 1 m 1h 3 3 m 3h 3 5 m 1h 3 7 m 2h 4 0 m 2h 4 3 d 1h 5 2 d 1h 5 3 d 1h 5 4 d 1h 6 8 s 2h 7 0 m 2h 7 7 d 4h 8 2 d 4h elemental analysis calculated c 28 h 37 n 5 o 12 s 3 c 45 95 h 5 10 n 9 57 s 13 14 measured c 46 00 h 5 12 n 10 00 s 13 58 the chemical structural formula of the compound xiv i is as follows j compound xiv j when hx is oxalic acid c 2 h 2 o 4 m z 556 m u2212 c 2 h 2 o 4 h 1 h nmr 300 mhz dmso d 6 u03b4 1 3 m 6h 2 3 m 1h 3 3 m 1h 3 8 m 3h 3 9 m 1h 4 1 m 2h 4 2 m 2h 4 4 d 1h 5 6 d 1h 5 7 d 1h 6 0 d 1h 7 1 s 2h 7 5 t 1h 8 1 d 2h 8 6 d 2h elemental analysis calculated c 46 h.