Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
  • C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D307/56—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D307/60—Two oxygen atoms, e.g. succinic anhydride

Definitions

• ABSTRACT OF THE DISCLOSURE Process for the preparation of tetronic acid in an alkyl ester of gamma-chloro-acetoacetic acid is reacted with an aryl amine to form a beta-arylamnio crotonic acid lactone. This is reacted with an alkali metal hydroxide to form a salt of tetronic acid from which tetronic acid is obtained by acidification.
• Tetronic acid is a known compound which is utilized, amongst other purposes, as an accelerating agent for photographic development. It has been prepared by catalytic hydration of alpha-bromtetronic acid which, in turn, is prepared from alpha, gamma dibromoacetoacetic esters by heating in vacuum. In this latter reaction an alkyl bromide splits out from the dibromo compound. The process, however, is not satisfactory since it starts from the dibromo compound which has to be prepared from the acetoacetic ester (US. Pat. 3,305,363).
• tetronic acid is prepared by a series of steps in which:
• an alkyl ester of gamma-chloroacetoacetic acid is reacted with an aromatic amine in a reaction inert aromatic hydrocarbon preferably at a temperature of from about 70 C. to 140 C. to form the corresponding beta-arylamino crotonic acid lactone,
• the desired product is most conveniently isolated by vacuum sublimation at pressures up to about 0.5 torr at a temperature of from about 95 C. to 100 C.
• the initial reaction preferably takes place in the presence of catalytic quantities of a lower alkanoic acid such as glacial acetic acid. From about 1% to 2% by weight of acid based on the weight of reaction inert solvent have been found to be efiective.
• Suitable reaction inert solvents include aromatic hydrocarbons such as benzene, toluene, and the xylenes boiling from about 70 C. to 140 C. at atmospheric pressure. Benzene is preferred because of its low boiling point.
• esters of gamma-chloro-acetoacetic acid can be employed in the initial reaction.
• Esters of lower alkanols such as methanol, ethanol and propanol are preferred because of their ready availability.
• Substituted and unsubstituted aromatic amines especially aryl amines including phenyl amines such as aniline, chloranilines and toluidines can be used to prepare the novel intermediate lactones.
• Aniline is preferred because of its ready availability.
• the lactone separates from the reaction inert aromatic hydrocarbon and is reacted with an alkali metal hydroxide, suitably an aqueous hydroxide prepared from potassium or sodium hydroxide.
• the amine which separates during the reaction may be recycled for the preparation of additional quantities of tetronic acid.
• a total of 17.5 g. of the recovered product was dissolved in 150 ml. of alcohol, the solution mixed with ml. of 20% aqueous sodium hydroxide and stirred for 12 hours at 35 C. to 40 C.
• the clear solution containing the sodium salt of tetronic acid was acidified with ml. of 18% hydrochloric acid and the solvent removed by evaporation to leave a dry residue.
• the residue was sublimated at a pressure of 0.5 torr at a bath temperature of 95 C. to 100 C. to provide 6 g. of pure tetronic acid (60% of theoretical yield based on starting lactone).
• the product was identified by elemental analysis, infra-red spectra and its solidification point of C. to 141 C.
• a process for the preparation of tetronic acid which comprises the steps of:
• a process for the preparation of tetronic acid which comprises the steps of:
• DONALD G. DAUS Primary Examiner A. M. T. TIGHE, Assistant Examiner

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

Applications Claiming Priority (1)

Publications (1)

Family

ID=4334771

Family Applications (1)

Country Status (6)

Cited By (6)

Families Citing this family (5)

• 1969
  • 1969-05-28 CH CH807669A patent/CH503722A/de not_active IP Right Cessation
• 1970
  • 1970-05-26 DE DE2025570A patent/DE2025570C3/de not_active Expired
  • 1970-05-27 GB GB1256847D patent/GB1256847A/en not_active Expired
  • 1970-05-28 FR FR7019529A patent/FR2048922A5/fr not_active Expired
  • 1970-05-28 NL NL7007741A patent/NL7007741A/xx not_active Application Discontinuation
• 1974
  • 1974-02-07 US US44102874 patent/USRE28242E/en not_active Expired

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