1 H NMR δ 1 . 5 ( br m , 3 H ) , 1 . 9 - 2 . 0 ( br m , 2 H ) , 3 . 4 - 3 . 5 ( br m , 2 H ) , 3 . 9 - 4 . 0 ( br m , 4 H ) , 6 . 8 - 6 . 9 ( m , 2 H ) , 6 . 95 ( s , 1 H ) , 7 . 15 - 7 . 2 ( m , 2 H ) , 7 . 25 ( s , 1 H ) , 7 . 55 - 7 . 6 ( br s , 1 H ) , 7 . 8 ( s , 1 H ) , 9 . 3 ( s , 1 H ) ; MS m / z 305 . 2 ( M + H ) , 237 . 2 ( M - C 3 H 3 N 2 · )