Abstract: An improved process for the preparation of 3,6-dichlorosalicylic acid by carboxylation of potassium 2,5-dichlorophenolate with carbon dioxide in xylene at elevated pressure, where the improvement consists of adding finely powdered, anhydrous potassium carbonate to the reaction mixture, whereby the yield of 3,6-dichloro-salicylic acid is significantly increased.
Abstract: New 4-hydroxy-3-(substitutedmethyl)benzeneacetic acids have been prepared which are useful as starting materials in the preparation of cephalosporin and penicillin derivatives.
Abstract: A dry alkali metal phenate can be more efficiently carbonated with carbon dioxide under pressure to an alkali metal carboxylate of a phenol, if the phenate is finely divided and the temperature during carbonation is maintained below about 135.degree. C. until at least about 25 mole percent of the carbon dioxide theoretically necessary to achieve complete carbonation is absorbed by the phenate. This method of carbonation is particularly useful to produce the sodium salt of salicylic acid.
Type:
Grant
Filed:
February 22, 1978
Date of Patent:
October 16, 1979
Assignee:
The Dow Chemical Company
Inventors:
Eugene R. Moore, David C. McDonald, Joseph Willner, Roger L. Briggs
Abstract: Alkali metal salicylate can be efficiently acidified and the salicylic acid product formed contemporaneously sublimed by contacting the salicylate as a solid with gaseous hydrogen chloride at the conditions specified. The temperature of the gaseous hydrogen chloride is controlled so that the heat required to sublime the salicylic acid product is predominantly supplied by the heat of reaction of the hydrogen chloride with the alkali metal salt of the carboxylic acid.
Type:
Grant
Filed:
April 7, 1978
Date of Patent:
January 30, 1979
Assignee:
The Dow Chemical Company
Inventors:
Eugene R. Moore, Roger L. Briggs, David C. McDonald, Richard Hoffman
Abstract: The invention relates to an improved method of preparing salicylic acid and derivatives from phenyl esters which comprises the step of fusing acetoxyphenyl, or derivative suitable for preparing the desired salicylic acid derivative, with M.sub.2 CO.sub.3 where M is potassium or sodium in the presence of carbon dioxide, at a temperature of from 150.degree. to 250.degree. C., and at a pressure of from atmospheric to 500 p.s.i.g.
Type:
Grant
Filed:
December 29, 1977
Date of Patent:
December 26, 1978
Assignee:
Merck & Co., Inc.
Inventors:
Leonard M. Weinstock, Arthur S. Wildman, Dennis M. Mulvey
Abstract: Metal complex polyazo dyes having, as a coupling component radical, the radical of a coupling component K, being the product of the condensation, under acidic conditions, of the formaldehyde with a compound or mixture of compounds of formula (a), ##STR1## AND/OR A COMPOUND OR MIXTURE OF COMPOUNDS OF FORMULA (B), ##STR2## WHEREIN EACH R.sub.1 , R.sub.2, R.sub.3 and R.sub.4 is independently is hydrogen, halogen, hydroxy or optionally substituted alkyl or alkoxy, andM is hydrogen or a non-chromophoric cation,The mol ratio of formaldehyde to the other compound(s) (a) and/or (b) being at least 0.6:1 and at least 50 mol % of the other compound(s) (a) and/or (b) containing a --COOM group, and, as diazo or bisdiazo component radical, a radical D- or -D- where D contains at least one metallized azo group, their production and their use for the dyeing of anionic dyeable substrates, particularly leather. The dyes have good levelling capacity and the obtained dyeings possess notable fastness to light.
Abstract: Salicylaldehyde and other hydroxybenzaldehydes are prepared by oxydation of a hydroxybenzyl alcohol in the presence of a platinum metal catalyst and lead, silver, tellurium or tin or compounds thereof as activator.
Type:
Grant
Filed:
April 29, 1977
Date of Patent:
October 10, 1978
Assignee:
Bayer Aktiengesellschaft
Inventors:
Kurt Bauer, Reiner Molleken, Helmut Fiege, Karlfried Wedemeyer