Selective Monophosphorylation of ethylenediamineSelective Monophosphorylation of ethylenediamine
SyntheticPage 491
Published Apr 01, 2011
A solution of the amine (45 mmol, 2.5 eq) in ethanol (9 mL) was added of recently distilled diisopropyl phosphonate (18 mmol, 1 eq) in carbon tetrachloride (4 mL) and ethanol (5 mL) dropwise. The temperature should not exceed 55–65°C during the addition. The mixture was stirred for 15 min until diisopropyl phosphonate wasn´t detected by TLC. The solution was evaporated under reduced pressure. Water (50 mL) was added to the residue, and the product was extracted twice with 20 mL portions of CH2Cl2; the organic phase was dried over MgSO4 and evaporated giving a pale yellow oil (2.02 g, 50%) product of high purity. Additional washes with water can be performed if necessary.