1 H - NMR ( CDCl 3 ) : 8 . 226 ( s , 1 H ) , 7 . 356 ~ 7 . 340 ( m , 5 H ) , 7 . 004 ( d , 1 H , J = 8 Hz ) , 6 . 535 ( d , 1 H , J = 8 . 4 Hz ) , 6 . 466 ( s , 1 H ) , 6 . 391 ( d , 1 H , J = 10 Hz ) , 5 . 589 ( d , 1 H , J = 10 Hz ) , 5 . 140 ( s , 2 H ) , 5 . 090 ( s , 2 H ) , 4 . 503 ( s , 2 H ) , 3 . 880 ( s , 3 H ) , 3 . 304 ( br , 1 H ) , 1 . 369 ( s , 6 H )