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US 5,245,069 AGranted
Process for the preparation of bis(aryl)-phosphorohalidates
AssigneeMerck & Co., Inc.
InventorJames W. McManus
Life of this patent
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Abstract
This invention relates to a novel process for preparing bis(aryl)phosphorohalidates which are useful in the synthesis of various enol phosphates. The process of this invention provides a means of producing a high-yield, high-purity product without the need for costly crystallization or impractical, high temperature distillations.
Claims8
A process for preparing a compound having the formula I:
- ##STR11## wherein:
- R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, nitro or a halogen;
- and
- X is bromine or chlorine;
- comprising the steps of:
- a) reacting a phosphoryl halide of the formula POX.sub.3, wherein X is defined as above, with a one to two-fold molar quantity of a phenol of the formula, ##STR12## in the presence of a dialkylaminopyridine and an arylphosphorodihalidate ##STR13## under a nitrogen atmosphere;
- b) heating the reaction mixture at temperature of from about 110.degree. C. to about 140.degree. C. for such period of time until the phenol has been consumed;
- c) cooling the reaction mixture to about 15.degree. C. to about 30.degree. C. for such period of time to effect crystallization of the catalyst;
- d) removing the catalyst by filtration;
- e) collecting the filtrate, containing the bis(aryl)phosphorohalidate, an arylphosphorodihalidate, and the arylphosphate;
- f) passing the filtrate through a wiped-film evaporator under high vacuum conditions to distill the arylphosphorodihalidate;
- and
- g) collecting the bis(aryl)phosphorohalidate product which distributes in the evaporation bottoms.
10 more elements
A process for preparing bis(2,4-dichlorophenylphosphorochloridate having the formula:
- ##STR14## comprising the steps of:
- a) reacting a phosphorylchloride with a one to two fold molar quantity of 2,4-dichlorophenol in the presence of 4-dimethylaminopyridine and 2,4-dichlorophenylphosphorodichloridate under a nitrogen atmosphere;
- b) heating the reaction mixture at a temperature of from about 110.degree. C. to about 140.degree. C. for such period of time until the 2,4-dichlorphenol has been consumed;
- c) cooling the reaction mixture to about 15.degree. C. to about 30.degree. C. for such period of time to effect crystallization of the catalyst;
- d) removing the catalyst by filtration;
- e) collecting the filtrate containing the bis(2,4-dichlorophenyl)phosphorochloridate, 2,4-dichlorophenylphosphorodichloridate and 2,4-dichlorophenylphosphate;
- f) passing the filtrate through a wiped-film evaporator under high vacuum conditions to distill the 2,4-dichlorophenylphosphorodichloridate;
- g) collecting the bis(2,4-dichlorophenyl)phosphorochloridate product which distributes in the evaporation bottoms.
5 more elements
Dependencies are inferred from the claim text.