1 H NMR ( 300 MHz , CDCl 3 ) δ 0 . 99 ( t , 3 H ) , 1 . 23 ( d , 6 H ) , 1 . 28 ( m , 2 H ) , 1 . 50 ( m , 2 H ) , 1 . 70 - 2 . 04 ( m , 8 H ) , 2 . 12 ( m , 1 H ) , 2 . 44 ( m , 1 H ) , 2 . 49 ( t , 2 H ) , 2 . 51 ( s , 3 H ) , 2 . 97 ( ( t , 2 H ) , 3 . 00 ( m , 2 H ) , 4 . 36 ( t , 2 H ) , 6 . 95 ( d , 1 H ) , 7 . 16 - 7 . 27 ( m , 2 H ) , 7 . 35 ( brs , 1 H , NH ) , 7 . 50 ( d , 2 H ) , 7 . 53 ( m , 1 H ) , 7 . 75 ( s , 1 H ) , 8 . 28 ( d , 2 H ) : MS ( m / e , M +): 596