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Azlactones synthesis

Benzilic acid rearrangement Benzoin reaction (condensation) Blanc chloromethylation reaction Bouveault-Blanc reduction Bucherer hydantoin synthesis Bucherer reaction Cannizzaro reaction Claisen aldoi condensation Claisen condensation Claisen-Schmidt reaction. Clemmensen reduction Darzens glycidic ester condensation Diazoamino-aminoazo rearrangement Dieckmann reaction Diels-Alder reaction Doebner reaction Erlenmeyer azlactone synthesis Fischer indole synthesis Fischer-Speior esterification Friedel-Crafts reaction... [Pg.1210]

Formation of 5-oxazolones (or azlactones ) (2) by intramolecular condensation of acylglycines (1) in the presence of acetic anhydride is known as the Erlenmeyer-Plochl azlactone synthesis. ... [Pg.229]

In 1959, Crawford and Little reported superior yields of 3 in reactions of aromatic aldehydes by using isolated, crystalline 2-phenyloxazol-5-one (2, Ri = Ph) compared to direct reaction with hippuric acid (1, Ri = Ph). An early report by Boekelheide and Schramm on the use of ketones in the Erlenmeyer azlactone synthesis includes treatment... [Pg.229]

Bismuth(III) acetate catalyzes the synthesis of azlactones (17) from aromatic aldehydes in moderate to good yields via the Erlenmeyer synthesis. While the standard procedure for azlactone synthesis consists of using a stoichiometric amount of fused anhydrous sodium acetate, 10 mol% of Bi(OAc)3 is sufficient to catalyze the reaction and the crude product is found to be > 98% pure. [Pg.231]

Modification of the Erlenmeyer reaction has been developed using imines of the carbonyl compounds, obtained with aniline," benzylamine or n-butylamine. Ivanova has also shown that an A-methylketimine is an effective reagent in the Erlenmeyer azlactone synthesis. Quantitative yield of 19 is generated by treatment of 3 equivalents of 2-phenyl-5(4ff)-oxazolone (2) (freshly prepared in benzene) with 1 equivalent of iV-methyl-diphenylmethanimine (18) in benzene. Products resulting from aminolysis (20), alkali-catalyzed hydrolysis (21), and alcoholysis (22) were also described. [Pg.231]

A variant of the Perkin reaction is the Erlenmeyer-Plochl-azlactone synthesis By condensation of an aromatic aldehyde 1 with an N-acyl glycine 5 in the presence of sodium acetate and acetic anhydride, an azlactone 6 is obtained via the following mechanism ... [Pg.226]

Erlenmeyer, E., Jr. Ann. 1893, 275, 1. Emil Erlenmeyer, Jr. (1864—1921) was bom in Heidelberg, Germany to Emil Erlenmeyer (1825—1909), a famous chemistry professor at the University of Heidelberg. He investigated the Erlenmeyer-Plochl azlactone synthesis while he was a Professor of Chemistry at Strasburg. [Pg.212]

Brooks, D. A. Erlenmeyer—Plochl Azlactone Synthesis in Name Reactions in Heterocyclic Chemistry, Li, J. J. Corey, E. J., Eds. Wiley Sons Hoboken, NJ, 2005, 229-233. (Review). [Pg.213]

Azlactone synthesis. Use of the reagent in the azlactone synthesis of amino acids is illustrated by a procedure for the preparation of DL-phenylalanine. - A mixture of 0.5 mole each of benzaldehyde, hippuric acid, and anhydrous sodium acetate is treated with 153 g. of acetic anhydride, and the mixture heated and stirred until the... [Pg.950]

Fig. 3 Overall sequence for azlactone synthesis, hydrogenation, and hydrolysis for the preparation of amino acids. Fig. 3 Overall sequence for azlactone synthesis, hydrogenation, and hydrolysis for the preparation of amino acids.
The enol acetates of a-keto acids can be accessed by a variation of the azlactone synthesis. They can also be reduced by Knowles catalyst, but ee values are 87-88% and the substrate to catalysis ratio needed for reduction does not allow this to be an economic approach to a-hydroxy acids although the reaction times are reduced compared with the corresponding carboxylate esters [9, 29]. [Pg.266]


See other pages where Azlactones synthesis is mentioned: [Pg.219]    [Pg.229]    [Pg.95]    [Pg.212]    [Pg.1174]    [Pg.751]    [Pg.655]    [Pg.123]   
See also in sourсe #XX -- [ Pg.225 ]




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