Irreversible reaction

Quaternisation of triphenylphosphine with methyl bromide

C18H15P+CH3BrC19H18BrP

Direction
Irreversible
Processes
1
Stated as
Rate law
Heat of reaction
ΔH = -100,000 kJ/kmol (one process)
Element balance
Checked: balances
As the processes state itStoichiometry, conversions, heats of reaction and catalyst windows are taken from each process's files with their provenance. The build checks only that each process's equation balances in every element, from the process's own component formulas; it does not check the numbers. A process's design maturity applies to them.

Species

SpeciesNameCASRoleCoefficient
C18H15PTriphenylphosphine603-35-0reactant-1
CH3BrBromomethane (methyl bromide)74-83-9reactant-1
C19H18BrPMethyltriphenylphosphonium bromide1779-49-3product1

In the processes

  • Methyltriphenylphosphonium bromide by semi-batch quaternisation of PPh3 with methyl bromide in toluene (820 t/a)Concept · not reviewed

    QUAT · Quaternisation of triphenylphosphine with methyl bromidePh3P + CH3Br → [Ph3PCH3]Br

    Stated as
    Rate law
    Phase
    liquid
    Element balance
    Balances in every element
    Heat of reaction
    ΔH = -100,000 kJ/kmol at 298.15 K, as written (assumed: ASSUMED order of magnitude (D-005): liquid methyl bromide and dissolved PPh3 to the precipitated salt, its heat of crystallisation included (CR101 adds none); no calorimetric value or formation enthalpy of the salt found openly (NIST WebBook lists none, 2026-11-06); a Menshutkin alkylation forming a crystalline salt, of the order of -80 to -120 kJ/mol, the upper end taken for the screening)
    Rate law
    basis: volume; driving: concentration; form: power_law; k: {"A":"4.728e8","Ea":70000}; orders: {"MEBR":1,"PPH3":1}; temperature range: 313.15 – 353.15 (assumed: ASSUMED effective rate (D-005): no open kinetics of PPh3 with methyl bromide in toluene found (2026-11-06); set so that a 3 h dosing at 333 K is dosing-controlled with a few per cent accumulated, US 3 334 144 A's 'reasonable rate at 50 C or above' as the only qualitative anchor; to be replaced by reaction calorimetry; D-011 screens k/10 and k/100)

Sources

What the processes cite for this reaction, each source once: for the reaction itself, its conversion, its heat of reaction or its catalyst. As the processes write them; DOIs, US patent numbers and web addresses are linked.

  1. US 3 334 144 A (Monsanto Research, 1967), background: the phosphine heated with methyl bromide, usually in benzene, in a pressure vessel, at 50 C or above for a reasonable rate

    For the reaction · cited by Methyltriphenylphosphonium bromide by semi-batch quaternisation of PPh3 with methyl bromide in toluene (820 t/a)

  2. Wikipedia, Methyltriphenylphosphonium bromide: Ph3P + CH3Br -> Ph3PCH3Br (route only)

    For the reaction · cited by Methyltriphenylphosphonium bromide by semi-batch quaternisation of PPh3 with methyl bromide in toluene (820 t/a)

  3. ASSUMED order of magnitude (D-005): liquid methyl bromide and dissolved PPh3 to the precipitated salt, its heat of crystallisation included (CR101 adds none); no calorimetric value or formation enthalpy of the salt found openly (NIST WebBook lists none, 2026-11-06); a Menshutkin alkylation forming a crystalline salt, of the order of -80 to -120 kJ/mol, the upper end taken for the screening

    For the heat of reaction · cited by Methyltriphenylphosphonium bromide by semi-batch quaternisation of PPh3 with methyl bromide in toluene (820 t/a)