1 H NMR ( 300 MHz , DMSO - d 6 ) δ 1 . 65 - 1 . 80 ( 3 H , m ) , 1 . 90 - 2 . 09 ( 1 H , m ) , 2 . 29 ( 3 H , s ) , 3 . 25 - 3 . 31 ( 2 H , m ) , 3 . 41 - 3 . 53 ( 2 H , m ) , 3 . 72 - 3 . 88 ( 3 H , m ) , 6 . 77 - 7 . 00 ( 5 H , m ) , 7 . 14 - 7 . 31 ( 3 H , m ) .