Method for preparing sterically hindered phosphoramidates
AssigneeGeneral Electric Company
InventorJames Anthony Cella
Life of this patent
Estimating the term…
Abstract
Sterically hindered phosphoramidates such as N,N′-bis[di-(2,6-xylenoxy)phosphoryl]piperazine are prepared by the reaction of a sterically hindered diaryl chlorophosphate, such as di-(2,6-xylyl) chlorophosphate, with a basic nitrogen compound containing at least two basic N-H groups, preferably a heterocyclic compound such as piperazine, in the presence of calcium oxide as an acid acceptor. The reaction is conducted in the presence of at least one dipolar aprotic solvent.
Claims14
A method for preparing a sterically hindered phosphoramidate which comprises contacting a sterically hindered diaryl chlorophosphate with a basic nitrogen compound containing at least two basic N-H groups in the presence of calcium oxide as an acid acceptor and at least one solvent which is dipolar aprotic, optionally in combination with a second solvent which is not dipolar artic,
- wherein the diaryl chlorophosphate has the formula
- wherein Ar is an aromatic group, each R1 is independently alkyl, aryl or halo, Q1 is oxygen or sulfur, Q2 is oxygen, sulfur, or NR1, and n has the value of 1 up to the number of free valency sites on the aromatic ring and at least one R1 substituent on the aryl ring is ortho to the heteroatom-phosphorus linkage;
- and
- wherein the basic nitrogen compound has the formula
- R2NH—CH2CH2—NHR2,
- wherein each R2 is a C1-4 primary or secondary alkyl radical or both R2 radicals taken together are ethylene or a benzene ring with nitrogens attached in the 1,2 positions;
- and
- wherein the dipolar aprotic solvent is dimethylformamide, dimethylacetamide, dimethyl sulfoxide or N-methylpyrrolidinone.
A method for preparing a phosphoramidate which comprises contacting a diaryl chlorophosphate with a basic nitrogen compound containing at least two basic N-H groups in the presence of calcium oxide as an acid acceptor and at least one solvent which is dipolar aprotic, optionally in combination with a second solvent which is not dipolar aprotic,
- wherein the diaryl chlorophosphate has the formula
- wherein Ar is an aromatic group, each R1 is independently alkyl, aryl or halo, Q1 is oxygen or sulfur, Q2 is oxygen, sulfur, or NR1, and n has the value of 1 up to the number of free valency sites on the aromatic ring and at least one R1 substituent on the aryl ring is ortho to the heteroatom-phosphorus linkage;
- and
- wherein the basic nitrogen compound has the formula
- R2NH—CH2CH2—NHR2 ,
- wherein each R2 is a C1-4 primary or secondary alkyl radical or both R2 radicals taken together are ethylene or a benzene ring with nitrogens attached in the 1,2 positions;
- and
- wherein the dipolar aprotic solvent is dimethylformamide, dimethylacetamide, dimethyl sulfoxide or N-methylpyrrolidinone;
- said phosphoramidate having a glass transition temperature of at least about 0° C.
A method for preparing N,N′-bis[di-(2,6-xylyl)phosphoryl]piperazine which comprises contacting di-(2,6-xylyl) chlorophosphate with piperazine in the presence of calcium oxide as an acid acceptor and dimethylformamide as solvent.
A method for preparing N,N′-bis[di-(2,6-xylyl)phosphoryl]piperazine which comprises contacting di-(2,6-xylyl) chlorophosphate with piperazine in the presence of calcium oxide as an acid acceptor and a mixture of dimethylformamide and chloroform as solvent.
Dependencies are inferred from the claim text.