US4398036A
Expired / Lapsed
US
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Preparation of N-monosubstituted carbamates
Assignee: Lyondell Chemical Technology LP
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Filing: 1980-05-02
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Granted: 1983-08-09
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Expires: 2000-05-02
Abstract
Abstract An improved process for the preparation of N-monosubstituted carbamates by reacting an aromatic primary amine, urea and a monohydric aliphatic alcohol in the presence of a strongly basic tertiary amine catalyst and optionally an inert solvent.
Inventors
- 👤 John J. McCoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:14
CPC Classifications
C; C07; C07C; C07C269/00; C07C269/04
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
125 words
A process for the preparation of an N-monosubstituted carbamic acid ester which comprises reacting an aromatic primary amine having the formula R(NH 2 )n wherein R is a substituted or unsubstituted aryl or aralkyl group containing one or more benzenoid rings which may be fused or joined by single valency bonds and n is an integer of 1 to 6, with urea and at least a stoichiometric amount of a monohydric aliphatic alcohol, based on the aromatic amine and, having from 1 to 10 carbon atoms at a temperature in the range of from about 100° C. to 250° C. in the presence of a catalytic amount of a strongly basic aliphatic, cycloaliphatic, araliphatic or aromatic tertiary amine containing from 1 to 18 carbon atoms.
Claim 2
Dependent Claim
125 words
A process for the preparation of an N-monosubstituted carbamic acid ester which comprises reacting an aromatic primary amine having the formula R(NH 2 )n wherein R is a substituted or unsubstituted aryl or aralkyl group containing one or more benzenoid rings which may be fused or joined by single valency bonds and n is an integer of 1 to 6, with urea and at least a stoichiometric amount of a monohydric aliphatic alcohol, based on the aromatic amine and, having from 1 to 10 carbon atoms at a temperature in the range of from about 100° C. to 250° C. in the presence of a catalytic amount of a strongly basic aliphatic, cycloaliphatic, araliphatic or aromatic tertiary amine containing from 1 to 18 carbon atoms.
Claim 3
Dependent Claim
26 words
A process according to claim 1 wherein the aromatic primary amine is selected from the group consisting of aniline, toluene diamines, naphthylamines, benzylamine and xylylene diamines.
Claim 4
Dependent Claim
13 words
A process according to claim 2 wherein the aromatic primary amine is aniline.
Claim 5
Dependent Claim
26 words
A process according to claim 1 wherein the molar ratio of aromatic primary amine to urea employed in the reaction is between about 10:1 to 0.1:1.
Claim 6
Dependent Claim
15 words
A process according to claim 4 wherein the molar ratio is between 5:1 to 0.25:1.
Claim 7
Dependent Claim
23 words
A process according to claim 1 wherein the monohydric aliphatic alcohol is selected from the group consisting of methanol, ethanol, n-butanol, and n-octanol.
Claim 8
Dependent Claim
11 words
A process according to claim 6 wherein the alcohol is methanol.
Claim 9
Dependent Claim
11 words
A process according to claim 6 wherein the alcohol is ethanol.
Claim 10
Dependent Claim
27 words
A process according to claim 1 wherein the alcohol is employed at a molar ratio of from about 1:1 to 15:1 based on the aromatic primary amine.
Claim 11
Dependent Claim
31 words
A process according to claim 1 wherein the tertiary amine catalyst is employed in an amount of from about 0.1 to 200 mole percent based on the aromatic primary amine employed.
Claim 12
Dependent Claim
22 words
A process according to claim 10 wherein the tertiary amine is employed in an amount of from 1 to 100 mole percent.
Claim 13
Dependent Claim
27 words
A process according to claim 1 wherein the tertiary amine catalyst is selected from the group consisting of triethylamine, trioctylamine, pyridine, imidazole, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 4-N,N-dimethylaminopyridine and 1,4-diazabicyclo[2.2.2]octane.
Claim 14
Dependent Claim
13 words
A process according to claim 12 wherein the tertiary amine catalyst is triethylamine.
Claim 15
Dependent Claim
13 words
A process according to claim 12 wherein the tertiary amine catalyst is pyridine.
Claim 16
Dependent Claim
13 words
A process according to claim 12 wherein the tertiary amine catalyst is 1,8-diazabicyclo[5.4.0]undec-7-ene.
Claim 17
Dependent Claim
13 words
A process according to claim 12 wherein the tertiary amine catalyst is 1,4-diazabicyclo[2.2.2]octane.
Claim 18
Dependent Claim
22 words
A process according to claim 1 wherein the reaction temperature is in the range of from about 125° C. to 225° C.
Claim 19
Dependent Claim
21 words
A process according to claim 1 wherein the reaction is carried out under a pressure of from 1 to 50 atmospheres.
Claim 20
Dependent Claim
19 words
A process according to claim 1 wherein the reaction is carried out in the presence of an inert solvent.
Claim 21
Dependent Claim
90 words
A process for the preparation of ethylphenylcarbamate which comprises reacting aniline with urea and at least a stoichiometric amount of ethyl alcohol based on the aromatic primary amine, at a temperature of from about 125° C. to 225° C. at a molar ratio of aniline to urea in the range of from about 5:1 to 0.25:1 in the presence of from about 1 to 100 mole percent, based on the aniline employed, of a strongly basic aliphatic, cycloaliphatic, araliphatic or aromatic tertiary amine containing from 1 to 18 carbon atoms.
Claim 22
Dependent Claim
90 words
A process for the preparation of ethylphenylcarbamate which comprises reacting aniline with urea and at least a stoichiometric amount of ethyl alcohol based on the aromatic primary amine, at a temperature of from about 125° C. to 225° C. at a molar ratio of aniline to urea in the range of from about 5:1 to 0.25:1 in the presence of from about 1 to 100 mole percent, based on the aniline employed, of a strongly basic aliphatic, cycloaliphatic, araliphatic or aromatic tertiary amine containing from 1 to 18 carbon atoms.
Claim 23
Dependent Claim
19 words
A process according to claim 20 wherein the reaction is carried out in the presence of an inert solvent.
Claim 24
Dependent Claim
38 words
A process for the preparation of a urethane which comprises reacting an aromatic primary amine with urea and an alcohol at a temperature of from about 100° C. to 250° C. in the presence of a tertiary amine.
Claim 25
Dependent Claim
38 words
A process for the preparation of a urethane which comprises reacting an aromatic primary amine with urea and an alcohol at a temperature of from about 100° C. to 250° C. in the presence of a tertiary amine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |