Method for the Manufacture of Anagrelide

摘要

Methods are provided for making certain 6,7-dihalo-1,5-dihydroimidazo [2,1-b] quinazolin-2 (3H) -ones from 2,3-dihalobenzaldehydes. A method is also provided for making the intermediate ethyl N-(2,3-dihalo-6-nitrobenzyl)glycines from 2,3-dihalobenzaldehydes and for reducing the glycine compounds using either SnCl 2 or a specially defined catalyst. A cyclization method to form the desired 6,7-dihalo-1,5-dihydroimidazo[2,1-b]quinazolin-2(3H)-ones from the corresponding iminoquinazoline compounds is further provided. These methods are particularly suitable in the manufacture of Anagrelide base.