Chemistry:Methyltriphenylphosphonium bromide

Methyltriphenylphosphonium bromide

Names
Preferred IUPAC name Methyltri(phenyl)phosphanium bromide
Identifiers
CAS Number	1779-49-3
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL54469
ChemSpider	67086
EC Number	217-218-9
PubChem CID	74505
UNII	LW2UZ3E9EG
CompTox Dashboard (EPA)	DTXSID30883580
InChI InChI=1S/C19H18P.BrH/c1-20(17-11-5-2-6-12-17,18-13-7-3-8-14-18)19-15-9-4-10-16-19;/h2-16H,1H3;1H/q+1;/p-1 Key: LSEFCHWGJNHZNT-UHFFFAOYSA-M
SMILES C[P+](C1=CC=CC=C1)(C2=CC=CC=C2)C3=CC=CC=C3.[Br-]
Properties
Chemical formula	C19H18BrP
Molar mass	357.231 g·mol−1
Appearance	white solid
Hazards
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H300, H301, H302, H312, H315, H319, H332, H411
GHS precautionary statements	P261, P264, P270, P271, P273, P280, P301+310, P301+312, P302+352, P304+312, P304+340, P305+351+338, P312, P321, P322, P330, P332+313, P337+313, P362, P363, P391, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Methyltriphenylphosphonium bromide is the organophosphorus compound with the formula [(C₆H₅)₃PCH₃]Br. It is the bromide salt of a phosphonium cation. It is a white salt that is soluble in polar organic solvents.

Synthesis and reactions

Methyltriphenylphosphonium bromide is produced by treating triphenylphosphine with methyl bromide:

Ph₃P + CH₃Br → Ph₃PCH₃Br

Methyltriphenylphosphonium bromide is the principal precursor to methylenetriphenylphosphorane, a useful methylenating reagent. This conversion is achieved by treating methyltriphenylphosphonium bromide with strong base.

Ph₃PCH₃Br + BuLi → Ph₃PCH₂ + LiBr + BuH