1 H NMR ( 300 MHz , DMSO - d 6 ) δ 1 . 71 - 1 . 80 ( 3 H , m ) , 2 . 02 ( 1 H , d , J = 6 . 1 Hz ) , 3 . 24 - 3 . 29 ( 2 H , m ) , 3 . 48 ( 2 H , q , J = 6 . 4 Hz ) , 3 . 76 - 3 . 86 ( 3 H , m ) , 6 . 94 - 7 . 03 ( 3 H , m ) , 7 . 07 ( 1 H , t , J = 2 . 3 Hz ) , 7 . 17 - 7 . 28 ( 3 H , m ) , 7 . 36 - 7 . 45 ( 1 H , m ) .