GB634563A - Improvements in or relating to the manufacture of aldols - Google Patents

Improvements in or relating to the manufacture of aldols

Info

Publication number
GB634563A
GB634563A GB8573/45A GB857345A GB634563A GB 634563 A GB634563 A GB 634563A GB 8573/45 A GB8573/45 A GB 8573/45A GB 857345 A GB857345 A GB 857345A GB 634563 A GB634563 A GB 634563A
Authority
GB
United Kingdom
Prior art keywords
alcohol
aldehyde
mixture
aldol
acid
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
Application number
GB8573/45A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Usines de Melle SA
Original Assignee
Usines de Melle SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Usines de Melle SA filed Critical Usines de Melle SA
Publication of GB634563A publication Critical patent/GB634563A/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
    • C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
    • C07C45/68—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
    • C07C45/72—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction of compounds containing >C = O groups with the same or other compounds containing >C = O groups

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

Aldols are prepared from unsubstituted acetaldehyde and its homologues by effecting aldolisation with an alkaline catalyst using as a diluent an amount of substantially anhydrous alcohol which is at least 20 per cent by weight of the initial alcohol-aldehyde mixture, adding to the reaction mixture an acid in a quantity at least sufficient to neutralize the catalyst and separating the aldol formed. Preferably, the alcohol forms with the neutralized reaction mixture, a mixture boiling at a temperature below that at which the aldol is dehydrated, whereby removal of unreacted aldehyde by distillation at the end of the reaction is facilitated; desirably, the mixture is acidified to a pH value of 4 to 5 thereby reducing dehydration of the aldol. A carboxylic aliphatic acid having from one to five carbon atoms is preferably used in acidifying the reaction mixtures; sulphuric acid is also mentioned. The aldolization may be carried out as a continuous process or not and at ordinary or super- or subatmospheric pressure; it is applicable to the method described in Specification 634,562. An example illustrates the preparation of acitaldol using ethyl alcohol as diluent; methanol and iso-propanol are also specified. Butyraldol may be prepared in like manner. The alcoholic solution of acetaldol obtained after distilling off unchanged aldehyde may be catalytically hydrogenated to butane-diol. A table is given comparing the p yields of acetaldol and undesirable higher polymers obtained at different temperatures from solutions of acetaldehyde in water and absolute alcohol respectively. The Specification as open to inspection under Sect. 91 includes the aldolization of any aliphatic aldehyde and is not limited as regards the amount of alcohol to be present. This subject-matter does not appear in the Specification as accepted.
GB8573/45A 1944-04-17 1945-04-06 Improvements in or relating to the manufacture of aldols Expired GB634563A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR634563X 1944-04-17

Publications (1)

Publication Number Publication Date
GB634563A true GB634563A (en) 1950-03-22

Family

ID=8993675

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8573/45A Expired GB634563A (en) 1944-04-17 1945-04-06 Improvements in or relating to the manufacture of aldols

Country Status (1)

Country Link
GB (1) GB634563A (en)

Similar Documents

Publication Publication Date Title
US2434110A (en) Process for hydrating olefinic aldehydes
Lin et al. A Study of the Mixed Tischtschenko Reaction
EP0289921A3 (en) Process for obtaining trialkylamines and methyle formiate in the preparation of trimethylolalkanes
Landau et al. Preparation of methyl isopropenyl ketone from methyl ethyl ketone and formaldehyde
Nield The Preparation of α-Bromo-α, β-unsaturated Ketones and Esters
GB1155022A (en) Hydroxymethane Carboxylic Acid Esters and process for their manufacture
Smissman et al. Conformational analysis of the Prins reaction
GB634563A (en) Improvements in or relating to the manufacture of aldols
US2698339A (en) Manufacture of pimelic acid and intermediates therefor
US2157348A (en) Production of aliphatic vinyl ethers by means of acetylene
GB646962A (en) Improvements in or relating to processes for the preparation of farnesylacetone
US2405451A (en) Process for producing low molecular weight lignin degradation products
Beringer et al. The Aromatization and Rearrangement of Cyclic Ketones. II. 3-Phenyl-5, 5-dimethylcyclohexenone1, 2
GB853266A (en) 1,3-butylene glycol
US2545261A (en) Catalysis of addition reactions
Hargreaves et al. 142. Reactions of carbinols in the presence of alkali. Part I. The reduction of ketones by primary alcohols
DE2228333C3 (en) Process for the preparation of optionally substituted 2-butyn-4ols
Clapperton et al. The Acid-Catalyzed Rearrangement of Substituted Phenylethynylcarbinols and Styrylethynylcarbinol
SU143787A1 (en) The method of obtaining alkyl-substituted nitroallyl
SU67945A1 (en) The method of producing acetaldehyde
GB742282A (en) Process for producing unsaturated carboxylic acids
US3283008A (en) Process for the preparation of 3-ketobutyraldehyde dimethylacetal-(1)
GB461662A (en) Improvements in the preparation of oxygenated aliphatic compounds
SU422734A1 (en) METHOD OF OBTAINING 8-
SU65174A1 (en) The method of obtaining coumarin