| 摘要 |
A method for the preparation of enprofylline is disclosed, which method comprises a) treating 6-amino-l-n-propyl-2,4-(lH,3H)-pyrimidinedione in formic acid with sodium nitrite in the presence of a catalyst to the formation of 6-amino-5-formamido-l-n-propyl-2,4-(lH,3H)-pyrimidinedione and b) performing a ring-closure reaction on the formed 6-amino-5-formamido-l-n-propyl-2,4-(lH,3H)-pyrimidinedione to the formation of 3,7-dihydro-3-n-propyl-lH-purin-2,6-dione. s |
