EP0868419A1 - Procede de preparation de n,n-dimethyl-n'-phenylurees - Google Patents
Procede de preparation de n,n-dimethyl-n'-phenylureesInfo
- Publication number
- EP0868419A1 EP0868419A1 EP96926275A EP96926275A EP0868419A1 EP 0868419 A1 EP0868419 A1 EP 0868419A1 EP 96926275 A EP96926275 A EP 96926275A EP 96926275 A EP96926275 A EP 96926275A EP 0868419 A1 EP0868419 A1 EP 0868419A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- dimcarb
- dimethyl
- dimethylamine
- substitution derivatives
- hydrogen atom
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/18—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of substituted ureas
- C07C273/1809—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of substituted ureas with formation of the N-C(O)-N moiety
- C07C273/1818—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of substituted ureas with formation of the N-C(O)-N moiety from -N=C=O and XNR'R"
- C07C273/1827—X being H
Definitions
- the present invention relates to a new and advantageous process for the preparation of N, N-dimethyl-N '-phenylurea and its substitution derivatives in the phenyl nucleus.
- N, N-dimethyl-N '-phenylurea and its substitution derivatives in the phenyl nucleus have been known for a long time and they are widely used in agriculture as total or selective herbicides.
- these compounds there may be mentioned N, N-dimethyl-N '- phenylurea, (fenuron), N' - (4-chlorophenyl) -N, N-dimethylurea (monuron), N ' - (3,4-dichlorophenyl) -N, N-dimethylurea (diuron), N, N-dimethyl-N '- [3- (trifluoromethyl) phenyl] urea (fluometuron), N, N-dimethyl-N' - (4-i-propylphenyl) -urea (isoproturon), N '- (3-chloro-4-methylphenyl) -N, N- dimethylurea (chlortoluron),
- urea is reacted with aniline or with one of its substitution derivatives in the phenyl nucleus, then reacting the product thus obtained with dimethylamine; these reactions are carried out in an alcohol as solvent, at a temperature of 100 ° C to 200 ° C.
- This synthesis process has the disadvantages of being accompanied by numerous side reactions and of providing the expected ureas with a low yield.
- the dimethylamine is reacted in aqueous solution with phenylisocyanate, optionally substituted.
- phenylisocyanate optionally substituted.
- the reaction with a large excess of aqueous dimethylamine solution which is circulated on the phenylisocyanate in the molten state (patent HU 178,312), or else a surfactant is added to the reaction mixture (patent ES 505,400), or else one uses an organic solvent soluble in water (patent ES 520,096).
- N, N-dimethyl-N '-phenylureas which is simpler and does not have the drawbacks of known processes. It has now been found that N, N-dimethyl-N '-phenylurea and its substitution derivatives in the phenyl nucleus can be prepared easily, with very high yields and excellent purity, by reacting the phenylisocyanate, or its substitution derivatives, with an excess of dimcarb acting both as a source of dimethylamine and as a solvent for the reaction, under reflux.
- the present invention relates to a process for the preparation of N, N-dimethyl-N '-phenylurea, and of its substitution derivatives in the phenyl nucleus, which is characterized in that the phenylisocyanate, or its substitution derivatives, with dimcarb.
- the present invention provides a process for the preparation of N, N-dimethyl-N '-phenylurea, and its substitution derivatives in the phenyl nucleus, corresponding to the general formula
- R x and R 2 each represent a hydrogen atom, or
- Rj . represents a chlorine atom and R 2 a hydrogen atom, or
- Ri and R 2 each represent a chlorine atom, or
- R x represents the trifluoromethyl group and R 2 a hydrogen atom, or
- R x represents the isopropyl group and R 2 a hydrogen atom, or R x represents the methyl group and R 2 a chlorine atom, or
- Ri represents the methoxy group and R 2 a chlorine atom, or
- Ri represents the 4-chlorophenoxy group and R 2 a hydrogen atom, characterized in that the phenylisocyanate or one of its substitution derivatives corresponding to the general formula is reacted
- R x and R 2 have the meanings given above, with dimcarb.
- dimethylammonium dimethylcarbamate or alternatively of compound or complex of dimethylamine and dimethylcarbamic acid.
- This compound is a liquid whose boiling point is close to 60 ° C at atmospheric pressure. Its composition does not generally correspond to the theoretical stoichiometry of dimethylammonium dimethylcarbamate, which is 2 moles of dimethylamine per one mole of carbon dioxide, but is rather about 1.7 moles of dimethylamine per 1 mole of carbon dioxide when 'Dimcarb is prepared, for example, under the conditions described below. Because of this deviation in stoichiometry of dimcarb from the theoretical stoichiometry of dimethylammonium dimethylcarbamate, it was preferred to use the term "dimcarb" in the present specification.
- N, N-dimethyl-N '-phenylurea and its substitution derivatives in the phenyl ring are obtained with 99%, if a phenylisocyanate of comparable purity is used, so that it is not necessary to subject them to a subsequent purification step.
- the phenylisocyanate or its substitution derivatives in the liquid or molten state, are added to an excess of dimcarb at 1 boiling, with stirring.
- the amount of dimcarb to be used according to the process of the invention is not critical, but it is however preferable to use a sufficient amount so that the reaction mixture obtained at the end of the reaction is easy to stir. This is why an amount of dimcarb is used such that the concentration of N, N-dimethyl-N '-phenylurea, or its substitution derivatives, in the final reaction mixture, is between 5 and 40% by weight, and preferably between 10 and 30% by weight, calculated for a quantitative yield, relative to the total weight of the reaction mixture. Concentrations below 5% are not attractive from an economic point of view, and concentrations above 40% cause difficulties in stirring the reaction mixture.
- the reaction mixture After adding all the isocyanate, the reaction mixture is still maintained under reflux for a period of 5 to 10 minutes.
- the excess dimcarb is then distilled, preferably in a rotary evaporator to prevent the reaction product from solidifying, preventing good evaporation of the dimcarb. It may be useful, but not essential, during this distillation, to maintain a slight stream of carbon dioxide in the evaporator, in order to avoid any risk of crystallization of the dimcarb.
- the unreacted dimcarb is easily and completely recovered, leaving in the reactor the N, N-dimethyl-N '-phenylurea or its substitution derivatives in the form of a very high dry powder. purity.
- the dimcarb recovered is of very high purity and can be recycled as it is for subsequent synthesis, without this affecting either the yield or the purity of the final product.
- the process for preparing the N, N-dimethyl-N'phenylureas according to the invention is therefore very simple and advantageous. It only requires the two reagents, phenylisocyanates and dimcarb, without the use of foreign solvents.
- the separation of the products obtained is done simply by evaporation of the excess of dimcarb, without it being necessary to purify the products obtained in a later stage.
- the process does not generate secondary products which would have to be separated and treated in a step later.
- Dimcarb can be synthesized in an autoclave equipped with an agitator and a double jacket for cooling.
- Anhydrous dimethylamine is introduced into the autoclave, then carbon dioxide gas.
- the flow rate of carbon dioxide is adjusted so as to maintain the temperature of the reaction mixture around 50 ° C.
- a vacuum is made in a stainless steel autoclave (maximum pressure of
- the flow of C0 2 is then adjusted so as to maintain a temperature of 45 to 55 ° C.
- the pressure is maintained at ⁇ 3.5 bar for some time and then slowly drops as the free dimethylamine is consumed.
- dimcarb 1560 g of dimcarb are thus obtained, containing 64.10% of dimethylamine (boiling temperature: 60-61 ° C).
- N '- (4-chlorophenyl) -N, N-dimethylurea (monuron) are obtained in the form of a white powder, a mp of 174.2 ° C, and a purity of 99.7 % (determined by HPLC). Yield: 100% on 4-chlorophenylisocyanate and 98.75% on dimethylamine used in the form of dimcarb.
- Example 3 The procedure is the same as in Example 3, but using 150 g of molten 3,4-dichlorophenylisocyanate (at about 99% purity, which represents 0.790 mol) as well as 500 g of the dimcarb recovered after distillation in examples 2 and 3, and which contains 64.05% of dimethylamine (7.10 mol). After adding isocyanate, the heating and stirring of the reaction mixture are continued for a further 10 minutes, which does not make it possible to completely redissolve the precipitate which has formed. The distillation of the excess dimcarb makes it possible to collect 437.8 g of the latter product, containing 64.15% of dimethylamine (i.e.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB9516444.8A GB9516444D0 (en) | 1995-08-04 | 1995-08-04 | Process for the production of n,n-dimethyl-n'-phenylureas |
GB9516444 | 1995-08-04 | ||
PCT/BE1996/000081 WO1997006134A1 (fr) | 1995-08-04 | 1996-08-01 | Procede de preparation de n,n-dimethyl-n'-phenylurees |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0868419A1 true EP0868419A1 (fr) | 1998-10-07 |
Family
ID=10779073
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP96926275A Withdrawn EP0868419A1 (fr) | 1995-08-04 | 1996-08-01 | Procede de preparation de n,n-dimethyl-n'-phenylurees |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0868419A1 (fr) |
GB (1) | GB9516444D0 (fr) |
WO (1) | WO1997006134A1 (fr) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102617407A (zh) * | 2012-03-06 | 2012-08-01 | 连云港市金囤农化有限公司 | 一种制备除草剂敌草隆的方法 |
CN102702030A (zh) * | 2012-06-12 | 2012-10-03 | 江苏快达农化股份有限公司 | 一种合成敌草隆原药的方法 |
CN102746194B (zh) * | 2012-07-19 | 2013-10-09 | 江苏扬农化工集团有限公司 | 一种连续化制备敌草隆的工业化生产方法 |
CN108863852B (zh) * | 2018-05-29 | 2021-03-19 | 安徽广信农化股份有限公司 | 一种敌草隆的加成方法 |
CN110938019B (zh) * | 2019-12-10 | 2022-06-24 | 江苏快达农化股份有限公司 | 连续化合成异丙隆方法 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2655445A (en) * | 1949-12-06 | 1953-10-13 | Du Pont | 3-(halophenyl)-1-methyl-1-(methyl or ethyl) ureas and herbicidal compositions and methods employing same |
US3994714A (en) * | 1965-10-28 | 1976-11-30 | Sandoz Ltd. | Method for selective herbicidal treatment of barley cultures |
CS243579B1 (cs) * | 1984-12-13 | 1986-06-12 | Tomas Sopuch | Kontinuální způsob přípravy derivátů N-aryl-N‘,N‘-dimethylmočovin |
-
1995
- 1995-08-04 GB GBGB9516444.8A patent/GB9516444D0/en active Pending
-
1996
- 1996-08-01 EP EP96926275A patent/EP0868419A1/fr not_active Withdrawn
- 1996-08-01 WO PCT/BE1996/000081 patent/WO1997006134A1/fr not_active Application Discontinuation
Non-Patent Citations (1)
Title |
---|
See references of WO9706134A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO1997006134A1 (fr) | 1997-02-20 |
GB9516444D0 (en) | 1995-10-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
FR2498598A1 (fr) | Procede de preparation d'urethanes aromatiques | |
EP0868419A1 (fr) | Procede de preparation de n,n-dimethyl-n'-phenylurees | |
US4178448A (en) | Process for preparing herbicidal triazines | |
EP0020281B1 (fr) | Préparation de benzoxazolone | |
FR2633290A1 (fr) | Procede pour la fabrication de carbamates d'iodoalcynyles | |
EP1140785B1 (fr) | Procede de preparation de para-trifluoromethylanilines polyhalogenees | |
EP0053981B1 (fr) | Procédé de fabrication de thiochloroformiates | |
JPH0149137B2 (fr) | ||
EP0098783B1 (fr) | Procédé de préparation de halogéno anilines | |
FR2510991A1 (fr) | Procede pour la preparation de methacrylamides et d'acrylamides n-substitues | |
FR2549048A1 (fr) | Procede de preparation du 2,6-difluorobenzonitrile a partir du 2,6-dichlorobenzonitrile | |
LU86296A1 (fr) | Procede de preparation d'une phenyluree substituee | |
CH624089A5 (fr) | ||
EP0347283B1 (fr) | Procédé de préparation de dichloro-2,6 amino-4 phénol | |
BE799932A (fr) | Nouvelles 6-amino-s-triazinediones utiles comme herbicdes | |
FR2769911A1 (fr) | Procede pour preparer des derives de 5-perfluoroalkyluracile | |
FR2510994A1 (fr) | Procede de preparation de l'herbicide phenmedipham | |
WO2024105187A1 (fr) | Procédé de préparation d'une amine primaire aromatique n-acétylée | |
EP0018931B1 (fr) | Préparation de benzoxazolone | |
FR2471967A1 (fr) | Procede de preparation de derives de p-phenylenediamine n,n-disubstitues | |
FR2647440A1 (fr) | Procede de bromation d'un derive du phenol | |
BE582143A (fr) | ||
BE569576A (fr) | ||
CH429701A (fr) | Procédé de production d'isocyanates organiques | |
FR2491923A1 (fr) | Procede pour produire du sulfochlorure de chlorobenzene |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19980302 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
17Q | First examination report despatched |
Effective date: 19990921 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20000119 |