Dimethylaminophosphorus dichloride is an organophosphorus compound with the formula Me2NPCl2 (Me = methyl). A colorless liquid, it is a reagent in the preparation of other organophosphorus compounds. Many analogous compounds can be prepared from the reactions of secondary amines and phosphorus trichloride:[1]
2 R2NH + PCl3 → R2NPCl2 + R2NH2Cl
Further equivalents of amine react with dialkylaminophosphorus dichlorides:
2 R2NH + R2NPCl2 → (R2N)2PCl + R2NH2Cl
Since the P-NR2 bond is not attacked by Grignard reagents, dimethylaminophosphorus dichloride can be selectively dimethylated:
2 MeMgBr + Me2NPCl2 → Me2NPMe2 + 2 MgBrClThe resulting dimethylphosphino derivative, a structural relative of tetramethylhydrazine, reacts with hydrogen chloride to give chlorodimethylphosphine:[2]
Me2NPMe2 + 2 HCl → ClPMe2 + Me2NH2Cl