1 H NMR ( 300 MHz , DMSO - d 6 ) δ 3 . 42 - 3 . 49 ( 2 H , m ) , 3 . 85 ( 3 H , s ) , 4 . 62 - 4 . 68 ( 2 H , m ) , 6 . 59 ( 1 H , dd , J = 8 . 7 , 2 . 7 Hz ) , 6 . 71 ( 1 H , t , J = 7 . 0 Hz ) , 6 . 97 ( 1 H , q , J = 3 . 2 Hz ) , 7 . 06 ( 2 H , d , J = 8 . 7 Hz ) , 7 . 42 ( 1 H , d , J = 8 . 7 Hz ) , 7 . 52 - 7 . 58 ( 2 H , m ) , 7 . 63 ( 1 H , dd , J = 7 . 2 , 1 . 5 Hz ) , 7 . 77 ( 1 H , d , J = 5 . 3 Hz ) .