Abstract: The invention provides a process for synthesizing chlorinated pyrimidines. The process includes reacting imidoyl chloride compounds with phosgene (COCl2). The imidoyl chloride compounds can be supplied as starting materials or can be produced by reacting organic amides with phosgene or reacting organic nitrites with hydrogen chloride. The chlorinated pyrimidines, such as 4,6-dichloropyrimidine, can be used to synthesize other compounds useful in a variety of compositions, such as fungicides, pesticides, and pharmaceuticals.

Abstract: The invention provides a process for synthesizing chlorinated pyrimidines. The process includes reacting imidoyl chloride compounds with phosgene (COCl2). The imidoyl chloride compounds can be supplied as starting materials or can be produced by reacting organic amides with phosgene or reacting organic nitrites with hydrogen chloride. The chlorinated pyrimidines, such as 4,6-dichloropyrimidine, can be used to synthesize other compounds useful in a variety of compositions, such as fungicides, pesticides, and pharmaceuticals.

Abstract: A facile process for the preparation of 4,6-dichloropyrimidine is provided, which utilizes quaternary ammonium salts or quaternary phosphonium salts as catalysts for the reaction of, for example, 4,6-dihydroxypyrimidine or 4-chloro-6-methoxypyrimidine with phosgene.

Abstract: 4,6-Dichloropyrimidine is prepared by treating 4,6-dihydroxypyrimidine with a chlorinating agent of the formula R.sup.1 R.sup.2 R.sup.3 PCl.sub.2 wherein R.sup.1, R.sup.2 and R.sup.3 are independently alkyl or aryl, or one or more of the groups R.sup.1, R.sup.2 and R.sup.3 is linked to a polymer support. Conveniently, the chlorinating agent may be prepared in situ by reacting the corresponding phosphine oxide with phosgene. Thus, in a preferred process, 4,6-dichloropyrimidine is prepared by treating 4,6-dihydroxypyrimidine with phosgene in the presence of a phosphine oxide.