1 H NMR ( 300 MHz , DMSO - d 6 ) δ 1 . 18 ( 3 H , t , J = 7 . 6 Hz ) , 1 . 69 - 1 . 80 ( 3 H , m ) , 1 . 95 - 2 . 03 ( 1 H , m ) , 2 . 59 ( 2 H , q , J = 7 . 6 Hz ) , 3 . 24 - 3 . 30 ( 2 H , m ) , 3 . 43 - 3 . 53 ( 2 H , m ) , 3 . 72 - 3 . 85 ( 3 H , m ) , 6 . 87 - 6 . 98 ( 4 H , m ) , 7 . 15 - 7 . 25 ( 4 H , m ) .