1 H NMR ( CDCl 3 ) δ 8 . 44 ( 1 H , br ) , 7 . 46 ( 1 H , d , J = 1 . 8 Hz ) , 7 . 39 ( 1 H , m ) , 7 . 29 - 7 . 22 ( 3 H , m ) , 4 . 71 - 4 . 59 ( 2 H , m ) , 3 . 85 ( 1 H , d , J = 6 . 1 Hz ) , 3 . 00 ( 1 H , d , J = 6 . 1 Hz ) , 2 . 76 ( 1 H , m ) , 2 . 57 ( 1 H , m ) , 2 . 29 ( 1 H , m ) , 2 . 27 ( 3 H , s ) , 2 . 09 ( 1 H , m ) .