1 H 　 NMR ( DMSO - d 6 , 400 MHz ) δ 9 . 67 ( s , 1 H ) , 9 . 17 ( s , 1 H ) , 7 . 80 ( brs , 2 H ) , 7 . 66 ( s , 1 H ) , 7 . 10 ( s , 1 H ) , 7 . 06 ( d , J = 8 Hz , 2 H ) , 4 . 00 ( s , 6 H ) , 3 . 23 - 2 . 76 ( m , 8 H ) , 2 . 76 - 2 . 59 ( m , 2 H ) , 1 . 18 ( t , J = 6 Hz , 3 H ) .