1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 73 ( 2 H , d ) , 1 . 95 - 2 . 07 ( 2 H , m ) , 3 . 39 - 3 . 50 ( 2 H , m ) , 3 . 83 ( 3 H , s ) , 4 . 19 ( 2 H , d ) , 5 . 13 ( 1 H , s ) , 5 . 17 ( 2 H , s ) , 6 . 37 ( 1 H , d ) , 7 . 00 ( 2 H , d ) , 7 . 38 ( 1 H , d ) , 7 . 44 ( 2 H , d ) , 7 . 66 ( 1 H , d ) , 8 . 12 ( 1 H , d ) ; m / z = 474 [ M + H ] +.