Claims
- 1. In a process for the preparation of pivaloylpyruvic acid ester by condensation of pinacolin with an oxalic acid dialkyl ester in the presence of an alcoholate as condensing agent wherein the reaction mixture, following completion of the reaction, is treated with a mineral acid to effect neutralization, the improvement which comprises carrying out the process in the presence of a water immiscible organic solvent, removing alcoholic constituents from the reaction mixture during the process before the treatment with mineral acid, mixing the reactants at a temperature of -50.degree. to +50.degree. C. and completing the reaction at a temperature of +35.degree. to 200.degree. C.
- 2. A process according to claim 1 wherein the reaction components are mixed at a temperature of -30.degree. to +30.degree. C. and the reaction is brought to completion at a temperature of 40.degree. to 140.degree. C.
- 3. A process according to claim 1 wherein an aliphatic, araliphatic or aromatic hyrocarbon or a halogenated aromatic hydrocarbon, with a boiling point above that of the alcohol split off in the condensation reaction, is employed as solvent.
- 4. A process according to claim 1 wherein the pinacolin is subjected to condensation with oxalic acid dimethyl ester in the presence of sodium methylate.
- 5. A process according to claim 1 wherein said oxalic acid dialkyl ester has the formula
- R.sup.1 O--CO--CO--OR.sup.1
- wherein
- R.sup.1 denotes alkyl or cycloalkyl.
- 6. A process according to claim 5 wherein the alcoholate has the formula
- (R.sup.2 O).sub.n M
- wherein
- R.sup.2 denotes alkyl or cycloalkyl,
- M is an alkali metal or alkaline earth metal and
- n is 1 or 2 according to the valency of the alkali metal or alkaline earth metal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2945657 |
Nov 1979 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 403,990, filed Aug. 2, 1982, now abandoned which is a continuation of Ser. No. 200,846, filed Oct. 27, 1982 (now abandoned).
Non-Patent Literature Citations (1)
Entry |
Royals, J. Amer. Chem. Soc., vol. 67, 1508-1509 (1945). |
Continuations (2)
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Number |
Date |
Country |
Parent |
403990 |
Aug 1982 |
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Parent |
200846 |
Oct 1982 |
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