17281-74-2Relevant articles and documents
METHOD FOR SYNTHESIZING BETA-DICARBONYL COMPOUNDS
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Paragraph 0139; 0140; 0141; 0142; 0143, (2014/04/03)
A method for synthesizing beta-dicarbonyl compounds, particularly beta-diketones, from at least two carbonyl compounds, such as esters and ketones, in the presence of a strong base or a mixture of strong bases by Claisen condensation with a titer of greater than 95%. The method includes providing a synthesis reactor on which a separation column, provided with a condenser and with at least one microwave generator, is mounted; feeding a first carbonyl compound and the strong base into the synthesis reactor; heating the reactor and starting up the condenser; starting up the microwave generator(s); when the mixture is brought to a boil at total flux, feeding the second carbonyl compound into the reactor; and after a waiting time, stopping the reactor and acidifying and washing the reaction mixture.)
Process for the preparation of linear 1,3-diketones
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, (2008/06/13)
There is disclosed a process for the preparation of 1,3-diketones of formula I STR1 wherein R1 and R2 are each independently of the other C1 -C20 alkyl, phenyl or phenyl which is substituted by halogen, hydroxy, NO2, C1 -C4 alkyl and/or C1 -C4 alkoxy, C7 -C9 phenylalkyl or a radical of formula II wherein A is C1 -C12 alkylene, phenylene or phenylene which is substituted by halogen, hydroxy, NO2, C1 -C4 alkyl and/or C1 -C4 alkoxy, or is C1 -C12 alkylene which is substituted by hydroxy, halogen and/or alkoxy, X is oxygen or sulfur, and R4 is hydrogen, C1 -C18 alkyl, phenyl or phenyl which is substituted by halogen, hydroxy, C1 -C4 alkyl, NO2 and/or C1 -C4 alkoxy, or is C7 -C9 phenylalkyl, and R3 is hydrogen, C1 -C20 alkyl, phenyl or phenyl which is substituted by halogen, hydroxy, C1 -C4 alkyl, NO2 and/or C1 -C4 alkoxy, or is C7 -C9 phenylalkyl. The process comprises carrying out a Claisen condensation of a ketone of formula III STR2 and an ester of formula IV STR3 wherein R5 is C1 -C5 alkyl, phenyl or phenyl which is substituted by halogen, C1 -C4 alkyl or hydroxy, the reaction being carried out with the base used as catalyst, a hydride of an alkali metal or alkaline earth metal or an alcoholate of C1 -C5 alkali metal or C1 -C5 alkaline earth metal, in a mixture of dimethyl sulfoxide and at least one organic solvent which is inert under the reaction conditions.
