Bis(diethylamino)chlorophosphine
# Bis(diethylamino)chlorophosphine

Bis(diethylamino)chlorophosphine is an organophosphorus compound with the formula $(Et_2N)_2PCl$ (Et = ethyl). A colorless liquid, it serves as a masked source of $PCl_2^+.$

## Synthesis and reactions

The compound is prepared by treatment of phosphorus trichloride with diethylamine:

    4 $Et_2NH$ + $PCl_3$ → $(Et_2N)_2PCl$ + 2 $Et_2NH_2Cl$

Illustrative of its utility is the synthesis of 1,2-bis(dichlorophosphino)benzene. The synthesis involves sequential lithiation of 1,2-dibromobenzene followed by treatment with $(Et_2N)_2PCl:$

    $C_6H_4Br_2$ + BuLi → $C_6H_4(Br)Li$ + BuBr
    $C_6H_4(Br)Li$ + $(Et_2N)_2PCl$ → $C_6H_4(Br)(P(NEt_2)_2)$ + LiCl
    $C_6H_4(Br)(P(NEt_2)_2)$ + BuLi → $C_6H_4(Li)(P(NEt_2)_2)$ + BuBr
    $C_6H_4(Li)(P(NEt_2)_2)$ + $(Et_2N)_2PCl$ → $C_6H_4[P(NEt_2)_2]_2$ + LiCl

Finally, the amino substituents are removed using hydrogen chloride:

    $C_6H_4[P(NEt_2)_2]_2$ + 8 HCl → $C_6H_4(PCl_2)_2$ + 4 $Et_2NH_2Cl$
