EP1628950A1 - Verfahren zur herstellung von dimethylcyanimidocarbonat - Google Patents
Verfahren zur herstellung von dimethylcyanimidocarbonatInfo
- Publication number
- EP1628950A1 EP1628950A1 EP04730506A EP04730506A EP1628950A1 EP 1628950 A1 EP1628950 A1 EP 1628950A1 EP 04730506 A EP04730506 A EP 04730506A EP 04730506 A EP04730506 A EP 04730506A EP 1628950 A1 EP1628950 A1 EP 1628950A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- stage
- formula
- neutralization
- dcc
- mol
- 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- Withdrawn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
- C07C261/00—Derivatives of cyanic acid
- C07C261/04—Cyanamides
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C251/00—Compounds containing nitrogen atoms doubly-bound to a carbon skeleton
- C07C251/02—Compounds containing nitrogen atoms doubly-bound to a carbon skeleton containing imino groups
Definitions
- the invention relates to a new process for the preparation of Dimemylcyanimidocarbontechnik (DCC, 3,3-Dimethoxy-2-azaprop-2-errr ⁇ itril).
- diethylcyanimidocarbonate can be prepared by reacting isolated diethylimidocarbonate with cyanamide under anhydrous conditions (Chem. Ber. 1967, 100. 2604).
- the yield of this process leaves something to be desired, so that an additional work-up step is necessary.
- dimethylcyanimidocarbonate is obtained by reacting an appropriate imidocarbonate with cyanamide in a two-phase system, the water and a water-immiscible organic solvent, for. B. toluene, can be produced (EP-A 0 014 064).
- dimethylcyanimidocarbonate can be prepared by first reacting sodium cyanide with methanol under alkaline conditions, then introducing chlorine, and after neutralizing the reaction mixture and adding cyanamide, the substituted N-cyanimidocarbonate formed is obtained from the organic phase after adding methylene chloride ( DE-A 3225 249).
- dimethylcyanimidocarbonate is obtained by first preparing the corresponding hnidocarbonate from methanol and cyanogen chloride and then adding an acid to a cyanamide solution (EP-B 0 523 619).
- the neutralized dimethylimidocarbonate of the formula (IT) thus obtained initiates an aqueous solution of cyanamide (amomemannitrile), the pH being kept neutral by simultaneous addition of an acid.
- oxidative secondary compounds are reduced in the presence of an extracting agent.
- non-product-containing solid particles are removed by clarifying filtration and
- the DCC of the formula (I) is concentrated in a sixth stage by extraction and distillation.
- DCC can be obtained in high purity in a simple manner by the process according to the invention.
- the neutralized dimethylimidocarbonate is stable for a sufficiently long time under the chosen reaction conditions in order to be able to be used in the subsequent reaction without loss of yield.
- the implementation according to the invention also has the advantage of increased environmental compatibility and reactor safety, since no health-threatening reactants or operating materials have to be used in large quantities.
- the starting materials sodium cyanide, sodium hydroxide solution, methanol, chlorine gas, cyanamide and sodium hydrogen sulfite are known chemicals.
- the reaction temperatures can be varied within a substantial range when carrying out the process according to the invention.
- the first stage is generally carried out at temperatures between -50 ° C and 0 ° C, preferably between -25 ° C and 0 ° C, particularly preferably at -5 ° C.
- the second stage is generally carried out at temperatures between -20.degree. C. and 0.degree. C., preferably between -10.degree. C. and 0.degree. C., particularly preferably at -5.degree.
- the third stage is generally carried out at temperatures between -20 ° C and + 30 ° C, preferably between -5 ° C and + 20 ° C.
- Sodium cyanide generally 0.8 to 1.5 mol, preferably 0.9 to 1.3 mol, particularly preferably 1.0 to 1.2 mol of sodium hydroxide and generally 2 to 10 mol, preferably 2 to 5 mol, particularly preferably 3 to 4 mol of methanol and generally 0.8 to 0.97 mol, preferably 0.85 to 0.95 mol, particularly preferably 0.90 to 0.95 mol of chlorine.
- Chlorine is preferably used in a slight deficit in order to minimize the formation of undesired by-products. It has surprisingly been found that when the chlorine is passed in, higher and more stable yields are obtained than when the chlorine is introduced.
- “Feeding” in the sense of the invention is understood here to mean that the chlorine is introduced into the gas space above the liquid reaction mixture, while when “feeding in” the end of the gas inlet tube is below the liquid surface. Concentration peaks on the gas discharge device are thus avoided during the conduction.
- the gas here chlorine
- the gas is absorbed via the liquid surface of the reaction mixture.
- the response time of the first stage is not critical and is between a few minutes and several hours. Depending on the batch size and the heat dissipation, the time for the chlorine gas to flow up is between 1 h and 20 h, generally between 5 h and 10 h.
- 0.5 to 1.5 mol, preferably 0.6 to 0.9 mol, of hydrochloric acid are generally employed per mol of sodium cyanide. However, other quantitative ratios can also be selected.
- the neutralization in carrying out the second stage of the process according to the invention is complete when a pH value of the reaction mixture in the range from pH 6.5 to pH 7.5, preferably from pH 6.8 to pH 7.2, has been reached.
- the neutralization of the dimethylimidocarbonate in the second stage is preferably carried out continuously with residence times of up to 30 min.
- Continuous operation is advantageous because it keeps the neutralized dimethylimidocarbonate sufficiently stable to be used in the subsequent reaction without loss of yield.
- a discontinuous mode of operation is also possible in principle, but lower yields must be expected here than with the continuous mode of operation.
- the continuous neutralization is carried out in a loop reactor with a suitable circulation ratio between pumped volume flow and discharged from the loop in order to dissipate the high heat of neutralization with the preferred residence times in the loop.
- the continuous dosing of hydrochloric acid into the loop is controlled by control technology so that the desired pH value range can be maintained during the entire neutralization.
- the dimethylimidocarbonate neutralized in the second stage is metered into the cyanamide solution provided within 20 to 120 min, preferably 30 to 90 min.
- the neutralized dimethylimidocarbonate is metered into the cyanamide directly from the neutralization stage in the above-mentioned period without buffering.
- the pH becomes neutral by adding further hydrochloric acid, preferably in the range from pH 6.5 to pH 7.5, particularly preferably in the range from pH 6.8 to pH 7.2 particularly preferably kept at pH 7.
- the process according to the invention is generally carried out under normal pressure. However, it is also possible, if appropriate, to work under increased or reduced pressure.
- all solvents which are suitable for such reactions and are immiscible with water can be used as the extracting agent.
- aromatic hydrocarbons such as, for example, benzene, toluene, ethylbenzene, xylene or decalin; halogenated hydrocarbons, such as chlorobenzene, dichlorobenzene, dichloromethane, chloroform, carbon tetrachloride, dichloroethane or trichloroethane.
- Toluene is particularly preferably used.
- the same extractant is then used in the sixth stage.
- a reducing agent suitable for these purposes preferably sodium bisulfite, is used.
- the procedure is generally such that the DCC suspension obtained after completion of the third stage is first mixed with toluene and then with sodium hydrogen sulfide to reduce oxidative by-products and subjected to clarification filtration to remove non-product-containing solid particles. The phases are then separated, the aqueous phase is thoroughly extracted and the combined toluene phases are distilled to dry and remove traces of hydrocyanic acid.
- the resulting solution of DCC in toluene preferably with a content between 10 and 15%, can be used directly in subsequent steps, e.g. an active ingredient synthesis (see below) can be used.
- the DCC obtained by the process according to the invention is a known synthesis component for substituted cyanoguanidine compounds which, after further reaction, can be converted into compounds with an insecticidal action (cf., for example, EP-A 0235 725) Preparation example
- Sodium cyanide (95%, 169.1 g, 3.28 mol) is cooled to -5 ° C. in 635 ml of water.
- Aqueous sodium hydroxide solution (45%, 320.0 g, 3.6 mol) and 372 g of methanol (11.6 mol) are then added dropwise, and chlorine gas (222.0 g, 3.13 mol).
- the mixture is stirred for a further 16 hours at -20 ° C and then neutralized within about 30 min. with hydrochloric acid (20%) until a pH of 7.0 is reached (380 ml, 2.3 mol hydrochloric acid).
- the suspension is within about 30 min. dosed at -5 ° C. in a solution of cyanamide (110.0 g, 2.62 mol) and water (233 g), the pH being kept at pH 7 with hydrochloric acid (20%).
- the temperature is then allowed to rise to + 15 ° C. in 1 h and the mixture is stirred at this temperature for a further hour.
- the pH is kept at pH 7 with hydrochloric acid (20%) over the entire subsequent stirring time.
- the amount of hydrochloric acid (20% solution) consumed during metering and stirring time is approx. 150 ml.
- the suspension is mixed with toluene (660 g), Celite 545 (6 g) and sodium hydrogensulfite (80.4 g, 39%).
- the mixture is stirred for 30 min at room temperature, the solid is filtered off, the phases are separated and the aqueous phase is rapidly extracted twice with toluene (430 g each time).
- the combined organic extracts are then dried by distillation and freed from traces of hydrocyanic acid.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10321269A DE10321269A1 (de) | 2003-05-13 | 2003-05-13 | Verfahren zur Herstellung von Dimethylcyanimidocarbonat |
PCT/EP2004/004594 WO2004101501A1 (de) | 2003-05-13 | 2004-04-30 | Verfahren zur herstellung von dimethylcyanimidocarbonat |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1628950A1 true EP1628950A1 (de) | 2006-03-01 |
Family
ID=33394498
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04730506A Withdrawn EP1628950A1 (de) | 2003-05-13 | 2004-04-30 | Verfahren zur herstellung von dimethylcyanimidocarbonat |
Country Status (9)
Country | Link |
---|---|
US (1) | US20070088177A1 (ko) |
EP (1) | EP1628950A1 (ko) |
JP (1) | JP2007501851A (ko) |
KR (1) | KR20060015575A (ko) |
CN (1) | CN100519518C (ko) |
DE (1) | DE10321269A1 (ko) |
IL (1) | IL171899A0 (ko) |
TW (1) | TW200505826A (ko) |
WO (1) | WO2004101501A1 (ko) |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
YU42018B (en) * | 1981-07-08 | 1988-04-30 | Lek Tovarna Farmacevtskih | Process for preparing dimethyl -(n-cyanimido) carbonate |
JPH0717621B2 (ja) * | 1986-03-07 | 1995-03-01 | 日本バイエルアグロケム株式会社 | 新規ヘテロ環式化合物 |
CA2032316A1 (en) * | 1989-12-26 | 1991-06-27 | John T. Lai | Process for the preparation of symmetrical azodinitrile dicarboxylic acids from keto acids |
DE4123608C1 (ko) * | 1991-07-17 | 1992-07-02 | Skw Trostberg Ag, 8223 Trostberg, De | |
DE4315625A1 (de) * | 1993-05-11 | 1994-11-17 | Hoechst Ag | Neue Derivate des 3-Fluorphenols, Verfahren zu ihrer Herstellung und ihre Verwendung |
-
2003
- 2003-05-13 DE DE10321269A patent/DE10321269A1/de not_active Withdrawn
-
2004
- 2004-04-30 WO PCT/EP2004/004594 patent/WO2004101501A1/de active Application Filing
- 2004-04-30 US US10/556,813 patent/US20070088177A1/en not_active Abandoned
- 2004-04-30 JP JP2006529723A patent/JP2007501851A/ja active Pending
- 2004-04-30 CN CNB2004800128550A patent/CN100519518C/zh not_active Expired - Fee Related
- 2004-04-30 EP EP04730506A patent/EP1628950A1/de not_active Withdrawn
- 2004-04-30 KR KR1020057020872A patent/KR20060015575A/ko not_active Application Discontinuation
- 2004-05-12 TW TW093113251A patent/TW200505826A/zh unknown
-
2005
- 2005-11-10 IL IL171899A patent/IL171899A0/en unknown
Non-Patent Citations (1)
Title |
---|
See references of WO2004101501A1 * |
Also Published As
Publication number | Publication date |
---|---|
IL171899A0 (en) | 2006-04-10 |
JP2007501851A (ja) | 2007-02-01 |
US20070088177A1 (en) | 2007-04-19 |
KR20060015575A (ko) | 2006-02-17 |
CN1787992A (zh) | 2006-06-14 |
TW200505826A (en) | 2005-02-16 |
WO2004101501A1 (de) | 2004-11-25 |
DE10321269A1 (de) | 2004-12-02 |
CN100519518C (zh) | 2009-07-29 |
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Legal Events
Date | Code | Title | Description |
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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 |
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17P | Request for examination filed |
Effective date: 20051213 |
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AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
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DAX | Request for extension of the european patent (deleted) | ||
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: BAUER, MICHAEL Inventor name: WEINTRITT, HOLGER Inventor name: HEYN, ARMIN |
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17Q | First examination report despatched |
Effective date: 20071011 |
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STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN |
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18W | Application withdrawn |
Effective date: 20110606 |