摘要:
The present disclosure provides new salts of 5-aminolevulinic acid (5-ALA) and new salts of 5-ALA esters, their preparation, formulation and use as photosensitizing agents in photodynamic therapy, diagnosis and cosmetic cares.
摘要:
The present invention relates to a process for the preparation of a particularly pure monochloroacetic acid, in which, in a first step, a hydrogenation of a mixture of mono- and dichloroacetic acid is carried out to a residual content of dichloroacetic acid of 400 to 600 ppm and, in a second step, this mixture is subjected to melt crystallization. The hydrogenation is carried out with a heterogeneous catalyst which comprises 0.1-5.0% by weight of palladium and in which active charcoal or silicon dioxide is used as the support.
摘要:
The alpha-halogenated carboxylic acids/esters are dehalogenated by reaction with hydrogen in the presence of a catalytically effective amount of (i) a Group VIII precious metal catalyst and (ii) either sulfur or a sulfur compound, or (iii) a novel precious metal/sulfur solid phase catalyst; the subject dehalogenation is especially adapted for enriching the monochloroacetic acid content of MCAA/DCAA mixtures.
摘要:
2,2-Dichloroacetoacetyl chloride having the formula: ##STR1## Process for producing 2,2-dichloroacetoacetyl chloride wherein acetyl chloride is reacted by means of a Lewis acid as a catalyst with chlorine at a temperature of 30.degree. to 60.degree. C. The mole ratio of acetyl chloride to the catalyst is from 1:0.005 to 1:0.5 and the mole ratio of acetyl chloride to the chlorine is from 1:0.1 to 1:1.5. The most preferred catalysts are aluminum chloride and aluminum bromide.
摘要:
Process of solubilizing alkali- and alkali-earth metal salts, characterized in that the salts are reacted in the presence of solvents if desired, with open-chain polyethyleneglycoldiethers of the general formulaRO--[CH.sub.2 CH.sub.2 O].sub.n R'wherein n = 6 or more and R and R' are identical or different and represent alkyl, aryl or cycloalkyl groups respectively, the polyethyleneglycoldiethers having at least 7 oxygen atoms which are separated from one another each by two carbon atoms. The process can also be used to dissolve alkali metals.
摘要:
Various dialkylammonium-2,4-dichlorophenoxyacetates having the formula ##STR1## wherein R.sub.1 and R.sub. 2 are radicals each selected from the group consisting of methyl and ethyl, are useful as plant growth regulators. Mono-substituted alkylamines are not suitable for processing into compounds of this invention. The compounds of the invention exhibit excellent water solubility characteristics and possess an exceptionally high and unexpected degree of effectiveness as a general weed killer on lawns, pasture lands, ponds, lakes, canals, ditches, etc. Methods of using and preparing these compounds are disclosed.
摘要:
A process for chlorinating or brominating a carboxylic acid which involves heating a carboxylic acid with chloride ions or bromide ions and molecular oxygen in the presence of nitrate ions, a carboxylic acid anhydride and a heavy metal cation. Acetic acid is converted to chloroacetic acid.
摘要:
The present invention concerns a process for the reduction of content of carboxylic acids and derivatives thereof in oleum, disulfuric acid or concentrated sulfuric acid. The invention further concerns a process for the manufacture of carboxylic acid anhydrides comprising the process for the reduction of content of carboxylic acids and derivatives thereof from oleum, disulfuric acid or concentrated sulfuric acid.