1499-29-2

Methylenebis (phosphonic dichloride) is an organophosphorus compound commonly used in phosphonation reactions. It is more reactive and faster than POCl. This is due to the fact that the phosphorus centre is more electrophilic due to the lack of electron feedback from the CH2 group.

Crystals of the Methylenebis(phosphonic dichloride) are monoclinic, space group C2/c, with a= 15·866(5), b= 5·845(1), c= 9·161 (3)A, β= 106·59(2)°, Z= 4. The molecules, which display a crystallographically imposed C2 symmetry, are linked together through two C–H ? O(P) hydrogen bonds, of length 3·23(1)A, into infinite chains in the z direction. Rigid-body analysis reveals that pronounced rotational and translational motions are associated with the axis of minimum inertia and least cross-section. Bond lengths (corrected for libration) are: P–Cl 1·994(2) and 1·997 (2), PO 1·463(4), P–C 1·804(4)A; angle P–C–P 116·4(4)°, the structure was solved by direct methods and refined by full-matrix least-squares to R 0·041 for 641 diffractometer-measured unique reflections^[1].

Methylenebis(phosphonic Dichloride) is used as a reagent in synthesis of several organic compounds including that of nucleoside 5'-methylenebis(phosphonate)s and bisphosphonated glycopeptide prodrugs for the treatment of osteomyelitis.

Methylenebis (phosphonic dichloride) can be used for the following studies:
(1) Synthesis of mycophenolic methylenebis(phosphonate) derivatives.
(2) Phosphonylation of nucleosides.
(3) Preparation of P,P′-partial esters of methylenebisphosphonic acid.
(4) Synthesis of symmetrical di- and tetra- esters of methylenebisphosphonic acid.

[1] SHELDRICK W. Crystal structure of methylenebis(phosphonic dichloride)[J]. Journal of The Chemical Society-dalton Transactions, 1975. DOI:10.1039/DT9750000943.