How is 4,4',4''-Phosphoryltrimorpholine (CAS: 4441-12-7) typically synthesized?

4,4',4''-Phosphoryltrimorpholine is synthesized by the phosphorylation of trimorpholine with phosphorus oxychloride in the presence of anhydrous conditions. The reaction is typically carried out at room temperature and yields up to 90% of the desired product. The catalyst and reagents are carefully selected to ensure high selectivity and yield.