Phosphorus acid catalyst for preparation of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphospha spiro (5,5) undecane

摘要

There is provided a process for reacting pentaerythritol with a trivalent phosphorus trihalide conducted in the presence of a phosphorus acid catalyst such as methyl acid phosphate. The reaction product is a useful intermediate for the preparation of flame retardants.