1 H - NMR ( 300 MHz , DMSO - d 6 ) : 1 . 3 - 1 . 6 ( m , 6 H ) , 2 . 29 ( t , 2 H ) , 2 . 4 - 2 . 7 ( m , 4 H ) , 3 . 67 ( m , 2 H ) , 3 . 95 ( m , 1 H ) , 4 . 9 - 5 . 7 ( brs , 2 H ) , 12 . 2 ( brs , 1 H )