Lead halophenoxides and carbonylation catalyst and method for preparing and employing them
AssigneeGeneral Electric Company
InventorsGrigorii Lev Soloveichik, Ben Purushatom Patel, John Yaw Ofori
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Abstract
Lead halophenoxides, especially bromophenoxides, are prepared by the reaction of lead(II) oxides with a hydroxyaromatic compound such as phenol and a chloride or bromide salt such as an alkali metal bromide, a tetraalkylammonium bromide or a bexaalkylguanidinium bromide. They are useful in catalyst compositions for the oxidative carbonylation of hydroxyaromatic compounds to diaryl carbonates.
Claims39
A lead haloaryloxide of the formula
- PbnOm(OA)(2−z)(n−m)Xz(n−m), (I)
- wherein A is an aromatic radical, X is chlorine or bromine, n has a value in the range of 1-3, m has a value in the range of 0-1 and z has a value in the range of 0.1-2.0, with the proviso that the values of n and m cannot be the same.
A lead halophenoxide of the formula PbnOm(OC6H5)(2−z)(n−m)Brz(n−m),
- wherein n has a value in the range of 2.5-3, m has a value in the range of 0.8-1 and z has a value in the range of 0.1-2.0.
A method for preparing a lead haloaryloxide which comprises contacting lead(II) oxide with at least one bromide or chloride at least one hydroxyaromatic compound, the molar ratio of lead to bromide or chloride being at least 2:1.
A method for preparing a lead bromophenoxide which comprises contacting lead(II) oxide with a tetraalkylammonium bromide, tetraalkylphosphonium bromide or hexaalkylguanidinium bromide and phenol;
- the molar ratio of lead to bromide being in the range of about 2-20:1 and said phenol being employed as a solvent.
A method for preparing a lead bromophenoxide which comprises contacting lead(II) oxide with an alkali metal bromide, acetonitrile and phenol;
- the molar ratio of lead to bromide being in the range of about 2-20:1, said phenol being employed as a solvent and the molar ratio of said acetonitrile to said alkali metal bromide being in the range of about 50-200:1.
A method for preparing a diaryl carbonate, said method comprising the step of contacting at least one hydroxyaromatic compound with oxygen and carbon monoxide in the presence of a carbonylation catalyst system comprising a catalytic amount of at least one haloaryloxide.
A method for preparing diphenyl carbonate which comprises contacting phenol with oxygen and carbon monoxide in the presence of an amount effective for carbonylation of at least one catalytic material comprising the following and any reaction products thereof:
- (A) palladium(II) 2,4-pentanedionate,
- (B) at least one tetraalkylammonium bromide or hexaalkylguanidinium bromide, and
- (C) at least one lead bromophenoxide.
A catalyst composition comprising the following and any reaction products thereof:
- (A) Group VIII metal having an atomic number of at least 44 or a compound thereof,
- (B) at least one bromide or chloride salt, and
- (C) at least one lead haloaryloxide.
A composition comprising the following and any reaction products thereof:
- (A) palladium(II) 2,4-pentanedionate,
- (B) at least one tetraalkylammonium bromide or hexaalkylguanidinium bromide, and
- (C) at least one lead bromophenoxide.
Dependencies are inferred from the claim text.