E.i. Dupont De Nemours and Company

John R Kosak

John F Kook

George E Heinsohn

Neville Everton Drysdale

Kamlesh Kumar Bhatia

Charles T Blaisdell

Rudolf E Svadlenak

Walter John Cordes

A process for the manufacture of 1,3- and 1,5-dialkylpiperidone-2 by reacting 2-methylglutaronitrile with a primary alkylamine in the presence of hydrogen, water, and a hydrogenation catalyst.

Process for the preparation of 1,3- and 1,5-dialkylpiperidone-2

A process is provided for separating high purity alkyl glycolate from a gaseous reaction mixture resulting from the catalyzed gas phase oxidation of alkyl glycolate. A hot solvent which is immiscible with water but selectively dissolves alkyl glycolate and alkyl glyoxylate is brought in contact with the gaseous reaction mixture, and water and alcohol vapors are removed from the hot solvent. The alkyl glyoxylate is removed from the solution by a first distillation and the alkyl glycolate and solvent are then separated in a second distillation.

Process for the isolation of alkyl glyoxylate

An improved process for the recovery of lactide or other dimeric cyclic ester from a gas stream containing the cyclic ester and such hydroxylic impurities as water and open-chain hydroxycarboxylic acids by scrubbing the gas stream with a nonpolar water-immiscible solvent at a temperature at which the cyclic ester is removed from the solvent and any water present in the gas stream is vaporized from the solvent. The cyclic ester is recovered from the solvent in a high state of optical purity.

Solvent scrubbing recovery of lactide and other dimeric cyclic esters

A process for reducing chloronitrobenzenes to the corresponding chloroanilines using a combination ruthenium-platinum catalyst is disclosed. The ratio of ruthenium to platinum in the catalyst is from 75:1 to 30:1. The pressure used is from 200 to 800 psi with from 400 to 600 psi being the preferred range. The temperature used is from 70.degree. to 160.degree. C. with from 110.degree. to 150.degree. C. being the preferred range.

Process for reducing chloronitrobenzenes using ruthenium with a minor

A continuous, close-coupled method for making N-methyl carbamate pesticides which comprises contacting the methyl isocyanate in a vapor phase mixture containing methyl isocyanate and water with a selected oxime or phenol, said mixture being the reaction product formed by oxidizing monomethylformamide. An optional intermediate step for preparing the methyl isocyanate/water vapor phase reaction mixture for contact with the oxime or phenol is to remove therefrom a portion of the water without liquefying the methyl isocyanate by cooling the mixture to a temperature below the dew point of water but above the dew point of the methyl isocyanate.

Process for the preparation of methyl carbamates and thioimidates

Isocyanates produced by vapor-phase catalytic oxidative dehydrogenation of corresponding N-substituted formamides are readily separated from by-product water by contacting the reaction mixture, in the vapor phase, with a cold brine mixture comprising water and about 25% to about 35% by weight of a salt or salts selected from the group consisting of NaCl, CaCl.sub.2, and MgCl.sub.2, the brine mixture having been maintained at a temperature between about 0.degree. C. and its freezing point prior to contact with the reaction mixture containing isocyanates.

Cryogenic brine separation of water and isocyanates

Halonitroaromatic compounds are reduced in the liquid phase with hydrogen, a palladium or platinum catalyst and a dehalogenation-suppressing amount of a compound of the formula ##STR1## wherein X is H, OH, alkyl, phenyl or mono- or dialkylphenyl.

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Greenville, DE, United States of America

John R Kosak