GB1559337A - Process for producing orthosilicic acid tetra alkyl esters - Google Patents
Process for producing orthosilicic acid tetra alkyl esters Download PDFInfo
- Publication number
- GB1559337A GB1559337A GB1276/79A GB127679A GB1559337A GB 1559337 A GB1559337 A GB 1559337A GB 1276/79 A GB1276/79 A GB 1276/79A GB 127679 A GB127679 A GB 127679A GB 1559337 A GB1559337 A GB 1559337A
- Authority
- GB
- United Kingdom
- Prior art keywords
- process according
- reaction
- active agent
- silicon
- alkyl group
- 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.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims description 61
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 title claims description 17
- 125000005907 alkyl ester group Chemical group 0.000 title 1
- 229910052710 silicon Inorganic materials 0.000 claims description 44
- 239000010703 silicon Substances 0.000 claims description 44
- 238000006243 chemical reaction Methods 0.000 claims description 39
- 150000002148 esters Chemical class 0.000 claims description 31
- 239000004094 surface-active agent Substances 0.000 claims description 27
- -1 alkali metal alkoxide Chemical class 0.000 claims description 22
- 229910045601 alloy Inorganic materials 0.000 claims description 21
- 239000000956 alloy Substances 0.000 claims description 21
- 125000000217 alkyl group Chemical group 0.000 claims description 20
- 239000011541 reaction mixture Substances 0.000 claims description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 12
- 229910052783 alkali metal Inorganic materials 0.000 claims description 12
- 125000004432 carbon atom Chemical group C* 0.000 claims description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- 239000003112 inhibitor Substances 0.000 claims description 7
- NQRYJNQNLNOLGT-UHFFFAOYSA-N Piperidine Chemical compound C1CCNCC1 NQRYJNQNLNOLGT-UHFFFAOYSA-N 0.000 claims description 6
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 claims description 6
- AWJUIBRHMBBTKR-UHFFFAOYSA-N isoquinoline Chemical compound C1=NC=CC2=CC=CC=C21 AWJUIBRHMBBTKR-UHFFFAOYSA-N 0.000 claims description 6
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 claims description 6
- 238000004821 distillation Methods 0.000 claims description 5
- SMWDFEZZVXVKRB-UHFFFAOYSA-N anhydrous quinoline Natural products N1=CC=CC2=CC=CC=C21 SMWDFEZZVXVKRB-UHFFFAOYSA-N 0.000 claims description 4
- 239000002585 base Substances 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 4
- 239000008396 flotation agent Substances 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 claims description 3
- 229910000519 Ferrosilicon Inorganic materials 0.000 claims description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 3
- 238000009835 boiling Methods 0.000 claims description 3
- 239000003995 emulsifying agent Substances 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 3
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 claims description 3
- 238000005554 pickling Methods 0.000 claims description 3
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 claims description 3
- 239000000080 wetting agent Substances 0.000 claims description 3
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 claims description 2
- 125000002943 quinolinyl group Chemical group N1=C(C=CC2=CC=CC=C12)* 0.000 claims description 2
- 150000003512 tertiary amines Chemical class 0.000 claims description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 34
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 8
- 239000000047 product Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 3
- 150000004703 alkoxides Chemical class 0.000 description 3
- 239000006260 foam Substances 0.000 description 3
- 238000010517 secondary reaction Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910000676 Si alloy Inorganic materials 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 150000001335 aliphatic alkanes Chemical class 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 125000004494 ethyl ester group Chemical group 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- QDRKDTQENPPHOJ-UHFFFAOYSA-N sodium ethoxide Chemical compound [Na+].CC[O-] QDRKDTQENPPHOJ-UHFFFAOYSA-N 0.000 description 2
- YZCKVEUIGOORGS-UHFFFAOYSA-N Hydrogen atom Chemical compound [H] YZCKVEUIGOORGS-UHFFFAOYSA-N 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 150000004790 diaryl sulfoxides Chemical class 0.000 description 1
- HHFAWKCIHAUFRX-UHFFFAOYSA-N ethoxide Chemical compound CC[O-] HHFAWKCIHAUFRX-UHFFFAOYSA-N 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 239000012429 reaction media Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 150000003335 secondary amines Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- LFQCEHFDDXELDD-UHFFFAOYSA-N tetramethyl orthosilicate Chemical compound CO[Si](OC)(OC)OC LFQCEHFDDXELDD-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
- C07F7/02—Silicon compounds
- C07F7/04—Esters of silicic acids
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Silicon Compounds (AREA)
Description
(54) PROCESS FOR PRODUCING ORTHOSILICIC ACID TETRA ALKYL ESTERS
(71) We, Dynamit Nobel
Aktiengesellschaft, a German company of 521 Troisdorf, bez Koln, Postfach 1209,
Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
This invention relates to a process for producing orthosilicic acid alkyl esters.
It is known from German patent specification 1 768 781 to produce orthosilicic acid tetraethyl esters by reacting metallic silicon with ethanol in the presence of concentrated alkali metal ethylate solutions; however this method has the disadvantage that it achieves relatively low space-time yields. This disadvantage is reduced to a certain extent by the method of British patent specification 1 237 159 wherein the reaction is carried out in the presence of at least 70% by weight of the desired orthosilicic acid tetraalkyl ester, which results necessarily in a lower concentration of the alkali metal alcoholate in the reaction mixture.
Both methods are very well suited to the production of the silicic acid tetramethyl ester. However, problems arise with the production of silicic acid tetraethyl ester and higher esters, which problems result in a reduction in the material yield and the space-time yield; the causes of these problems are still unexplained. In the production of silicic acid tetraethyl ester and higher esters, the reaction rate with respect to the silicon put in at the outset decreases steadily during the course of the reaction without the reaction constituents being reacted to completion. This reduction in the reaction rate is quicker than the reduction in the concentration of the constituents. In the case of the production of silicic acid tetraethyl ester, this results, for instance, in only about 40% of the silicon used reacting, the reaction then ceasing despite a surplus of ethanol.
A possible explanation for the reduction in the reaction rate is that in the course of the reaction, products are formed which adversely affect the surface of the silicon with regard to its reactivity with the alcohol. It has now been found that this adverse affect on the reaction rate can be reduced by adding a surface-active agent to the reaction mixture.
According to the present invention there is provided a process for producing an orthosilicic acid tetraalkyl ester, each alkyl
group of which has a carbon chain containing trom 2 to 6 carbon atoms, which process comprises reacting elemental silicon or an alloy containing silicon with an alkanol having a carbon chain containing from 2 to 6 carbon atoms in the presence of an alkali metal alkoxide, the alkyl group of which is identical with the alkyl group of the alkanol, the reaction being carried out in the presence of a surface-active agent, to form the desired ester.
Preferably the ester produced is the ethyl ester, in which case the alkanol is ethanol and the alkali metal alkoxide is the ethoxide, preferably sodium ethoxide, also known as sodium ethanolate.
The surface-active agent may be added at any time during the reaction. If it is added at a point when the reaction rate has already dropped considerably, it has been found when producing the ethyl ester that a rise in the rate is obtained shortly afterwards to a value which is considerably higher than the value which obtains at the beginning of the reaction when no surface-active agent is present.
The addition of the surface-active agent right at the beginning of the reaction has been found to have the effect that the reaction between the silicon or alloy and the alkanol takes place without any appreciable hindrances, and the disadvantages described above, if they occur at all, do so only on a reduced scale.
There may be used as surface-active agents wetting agents, emulsifiers, penetrating agents or flotation agents,nsofar as these do not enter into disruptive reactions with the reactants or products. The amount to be added depends on the type of agent used. In general it is preferred to use small quantities below 1% by weight, relative to the silicon used, since these amounts suffice to cover the surface of the elemental silicon or the alloy containing silicon.
In one preferred embodiment there is used as surface active agent a nitrogenous organic base, for example a cyclic tertiary or secondary amine such as quinoline, isoquinoline, pyridine or piperidine. In another preferred embodiment there is used as surface-active agent one of the inhibitors commonly used in inhibitor-containing metal pickling solutions which are employed in metal treating and derusting processes. For example the inhibitor may be a diaryl sulfoxide, an alkylene sulfoxide or a dialkyl thiourea. The use of these compounds has the further advantage that they more or less strongly counteract the disruptive secondary reaction, mentioned hereinafter, which results in the formation of alkanes and water.
When flotation agents are used as the surface-active agent it can often happen, particularly when foamers are also used, that the reaction mixture foams up and the greater part of the elemental silicon or alloy containing silicon collects together with the foam in the upper part of the reaction vessel. It is then advisable to wash the foam, together with the silicon or alloy, via a suitable overflow into a second reaction vessel and to continue the reaction therein after adding a defoaming agent and fresh alkanol, alkoxide and possibly some of the ester product. The silicon or alloy thus washed over generally no longer shows the inertness described above and reacts like fresh silicon.
In principle, the process may be performed in the manner disclosed in German Patent
Specification 17 68 781 or British Patent
Specification 1 237 159. Thus with reference to the latter specification, there is preferably present at all times during the reaction at least 70% by weight of the orthosilicic acid tetraalkyl ester, based on the total weight of liquid present during the reaction. The concentration of the individual components in the system can be varied within wide limits. It is an advantage, however, to select the proportions so that they give a mixture which is capable of being easily stirred. It is preferred, too, that the alkoxide present becomes dissolved in the alkanol. It is also possible to carry out the process without excess silicon or alloy in the system, and to supply the silicon or alloy together with the alkanol only at the rate at which it reacts. The process according to the invention may be carried out in batches or continuously. Separation of the desired reaction product from the product mixture is preferably carried out by distillation.
During the reaction between the silicon or alloy and the alkanol, nascent hydrogen is formed, which in a secondary reaction hydrogenates the alcohol to a small degree, forming alkanes and water, (c.f. Houben
Weyl VI/2 page 100). This water reacts in a further secondary reaction with the catalyst present, i.e. the alkoxide which thereby suffers reduced activity, and also with the ester formed in the alkaline reaction medium. The removal of the water from the system is preferably effected by partially distilling the reaction mixture, using the hydrogen which is produced or an inert gas, for example nitrogen, as an entraining gas. The aqueous, gaseous distillation products are condensed in a manner such that the condensate cannot run back directly into the reaction vessel.
Thereafter the distillate may be returned to the remainder of the reaction mixture in the reaction vessel via suitable dehydrating agents.
There may be a slight consumption of the surface-active agent during the course of the process because of loss during distillation.
Replenishment of the surface-active agent to make up for the slight consumption may be effected together with the addition of alkanol.
In addition to elemental silicon, it is possible to use an alloy containing silicon in the process according to the invention. Preferably there is used ferrosilicon or other silicon alloys with a proportion of silicon above 50%. The grain size of the silicon or silicon alloy is preferably not greater than 100 ,u, and more preferably from 2 to 20 ,u.
It is a preferred feature of the present invention that the process be carried out under pressure at a temperature which is greater than the normal boiling temperature (at one atmosphere absolute) of the reaction mixture. It is also preferred that the process is additionally or alternatively carried out in the presence of a compound containing a methoxy group which is not an alkali metal 2-methoxy ethoxide or 2-methoxy ethanol and which increases the rate of reaction.
Our copending patent application
No.29927/76 (Serial No.1559335) from which this application is divided describes and claims a process for producing an orthosilicic acid tetraalkyl ester, each alkyl group of which has a carbon chain containing from 2 to 6 carbon atoms, which process comprises reacting elemental silicon or an alloy containing silicon with an alkanol having a carbon chain containing from 2 to 6 carbon atoms in the presence of an alkali metal alkoxide, the alkyl group of which is identical with the alkyl group of the alkanol, the reaction being carried out under pressure at a temperature which is greater than the normal boiling temperature of the reaction mixture, to form the desired ester.
Our other copending patent application No.79/01185, (Serial No.1559336) also divided out of application No.29927/76, (Serial No.1559335) describes and claims a process for producing an orthosilicic acid tetraalkyl ester, each alkyl group of which has a carbon chain containing from 2 to 6 carbon atoms, which process comprises reacting elemental silicon or an alloy containing silicon with an alkanol having a carbon chain containing from 2 to 6 carbon atoms in the presence of an alkali metal alkoxide, the alkyl group of which is identical with the alkyl group of the alkanol, the reaction being carried out in the presence of a compound containing a methoxy group which is not an alkali metal 2-methoxy ethoxide or 2-methoxy ethanol and which increases the rate of reaction, to form the desired ester.
WHAT WE CLAIM IS:
1. A process for producing an orthosilicic acid tetraalkyl ester, each alkyl group of which has a carbon chain containing from 2 to 6 carbon atoms, which process comprises reacting elemental silicon or an alloy containing silicon with an alkanol having a carbon chain containing from 2 to 6 carbon atoms in the presence of an alkali metal alkoxide, the alkyl group of which is identical with the alkyl group of the alkanol, the reaction being carried out in the presence of a surface-active agent, to form the desired ester.
2. A process according to claim 1 wherein the surface-active agent is a wetting agent.
3.A process according to claim 1 wherein the surface-active agent is a flotation agent.
4. A process according to claim 1 wherein the surface-active agent is an emulsifier or a pentrating agent.
5. A process according to claim 1 wherein the surface-active agent is a nitrogenous organic base.
6. A process according to claim 5 wherein the base is a cyclic secondary or tertiary amine.
7. A process according to claim 6 wherein the base is quinoline, isoquinoline, pyridine or piperidine.
8. A process according to claim 1 wherein the surface-active agent is a metal pickling solution inhibitor.
9. A process according to claim 8 wherein the inhibitor is a diaryl sulphoxide, an alkylene sulphoxide or a dialkyl thiourea.
10. A process according to any one of the preceding claims wherein the surface-active agent is present in an amount of less than 1% by weight based on the silicon.
11. A process according to any one of the preceding claims which is carried out continuously and wherein there is produced a reaction mixture from which is removed the desired ester, hydrogen and surface-active agent, and to which is added further elemental silicon or alloy containing silicon and further of the agent.
12. A process according to any one of the preceding claims wherein part of the reaction mixture is removed from the reaction vessel by distillation, dehydrated and then admixed with the remainder of the reaction mixture.
13. A process according to any one of the preceding claims wherein the alkyl group of the orthosilicic acid tetraalkyl ester and the alkanol is an ethyl group.
14. A process according to any one of the preceding claims wherein the elemental silicon or alloy containing silicon has a grain size of from 2 to 20 ju.
15. A process according to any one of the preceding claims wherein the alloy containing silicon is ferrosilicon.
16. A process according to any one of the preceding claims wherein there is present at all times during the reaction at least 70% by weight of the orthosilicic acid tetraalkyl ester, based upon the total weight of liquid present during the reaction.
17. A process according to claim 1 substantially as hereinbefore described.
18. An orthosilicic acid tetraalkyl ester whenever produced by the process according to any one of the preceding claims.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (18)
1. A process for producing an orthosilicic acid tetraalkyl ester, each alkyl group of which has a carbon chain containing from 2 to 6 carbon atoms, which process comprises reacting elemental silicon or an alloy containing silicon with an alkanol having a carbon chain containing from 2 to 6 carbon atoms in the presence of an alkali metal alkoxide, the alkyl group of which is identical with the alkyl group of the alkanol, the reaction being carried out in the presence of a surface-active agent, to form the desired ester.
2. A process according to claim 1 wherein the surface-active agent is a wetting agent.
3.A process according to claim 1 wherein the surface-active agent is a flotation agent.
4. A process according to claim 1 wherein the surface-active agent is an emulsifier or a pentrating agent.
5. A process according to claim 1 wherein the surface-active agent is a nitrogenous organic base.
6. A process according to claim 5 wherein the base is a cyclic secondary or tertiary amine.
7. A process according to claim 6 wherein the base is quinoline, isoquinoline, pyridine or piperidine.
8. A process according to claim 1 wherein the surface-active agent is a metal pickling solution inhibitor.
9. A process according to claim 8 wherein the inhibitor is a diaryl sulphoxide, an alkylene sulphoxide or a dialkyl thiourea.
10. A process according to any one of the preceding claims wherein the surface-active agent is present in an amount of less than 1% by weight based on the silicon.
11. A process according to any one of the preceding claims which is carried out continuously and wherein there is produced a reaction mixture from which is removed the desired ester, hydrogen and surface-active agent, and to which is added further elemental silicon or alloy containing silicon and further of the agent.
12. A process according to any one of the preceding claims wherein part of the reaction mixture is removed from the reaction vessel by distillation, dehydrated and then admixed with the remainder of the reaction mixture.
13. A process according to any one of the preceding claims wherein the alkyl group of the orthosilicic acid tetraalkyl ester and the alkanol is an ethyl group.
14. A process according to any one of the preceding claims wherein the elemental silicon or alloy containing silicon has a grain size of from 2 to 20 ju.
15. A process according to any one of the preceding claims wherein the alloy containing silicon is ferrosilicon.
16. A process according to any one of the preceding claims wherein there is present at all times during the reaction at least 70% by weight of the orthosilicic acid tetraalkyl ester, based upon the total weight of liquid present during the reaction.
17. A process according to claim 1 substantially as hereinbefore described.
18. An orthosilicic acid tetraalkyl ester whenever produced by the process according to any one of the preceding claims.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19752532473 DE2532473A1 (en) | 1975-07-19 | 1975-07-19 | METHOD FOR MANUFACTURING ORTHOCIESEL ACID TETRAALKYLESTERS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1559337A true GB1559337A (en) | 1980-01-16 |
Family
ID=5952000
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1276/79A Expired GB1559337A (en) | 1975-07-19 | 1976-07-19 | Process for producing orthosilicic acid tetra alkyl esters |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE2532473A1 (en) |
| GB (1) | GB1559337A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2816386A1 (en) * | 1978-04-15 | 1979-10-25 | Dynamit Nobel Ag | METHOD FOR MANUFACTURING ORTHOCIESEL ACID TETRAALKYLESTERS |
-
1975
- 1975-07-19 DE DE19752532473 patent/DE2532473A1/en not_active Ceased
-
1976
- 1976-07-19 GB GB1276/79A patent/GB1559337A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2532473A1 (en) | 1977-02-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |