1 H NMR ( 400 MHz ; DMSO ; Me 4 Si ) , δ ( ppm ) : 1 H NMR ( 400 MHz , dmso ) δ 8 . 99 ( d , J = 7 . 4 Hz , 1 H ) , 8 . 30 ( s , 3 H ) , 7 . 58 ( d , J = 7 . 2 Hz , 2 H ) , 7 . 52 ( s , 3 H ) , 7 . 43 - 7 . 31 ( m , 7 H ) , 7 . 27 ( d , J = 7 . 1 Hz , 4 H ) , 6 . 97 ( d , J = 8 . 3 Hz , 1 H ) , 5 . 08 ( s , 2 H ) , 4 . 37 ( dd , J = 13 . 6 , 8 . 1 Hz , 1 H ) , 3 . 80 ( s , 1 H ) , 3 . 58 ( s , 3 H ) , 2 . 94 ( ddd , J = 22 . 7 , 13 . 9 , 7 . 3 Hz , 2 H ) , 2 . 05 ( s , 1 H ) , 1 . 35 ( d , J = 7 . 0 Hz , 3 H ) , 1 . 28 ( s , 12 H ) .