Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

3.4- Dimethoxyphenylpyruvic acid

The Decker-Wahl plan has two identical branches that converge in the 4th stage in a pseudo-dimerization of 3,4-dimethoxyphenylpyruvic acid in the presence of ammonia. The linearized Decker-Wahl plan in Figure 4.52 shows a net degradation of 86 g/mol per... [Pg.155]

Dimethoxyphenylpyruvic acid can be isolated from this solution in the following way (J. S. Buck and W. S. Ide). The aqueous solution of the sodium salts is saturated with sulfur dioxide, while the temperature is maintained below 40°. The benzoic acid precipitates and is filtered off with suction and washed with a small quantity of water. The filtrate and washings are placed in a 3-I. round-bottomed flask provided with a mechanical stirrer and heated to boiling. Concentrated hydro-... [Pg.33]

Homoveratric acid has been prepared by the methylation of homoprotocatechuic acid1 and of homovanillic acid2 with methyl iodide, and from veratric aldehyde through the azlactone and 3,4-dimethoxyphenylpyruvic acid.3 The procedure given here is adapted from that last mentioned and from that used for the preparation of -methoxyphenylacetic acid.4... [Pg.34]

Treatment of 3,4-dihydro-6,7-dimethoxyisoquinoline hydrochloride with an excess of ethyl vinyl ketone gave the epimers (30) and (31) in variable proportions, depending on the pH of the reaction medium.0-Methylpeyoxylic acid (32 R = H) and 0-methylpeyoruvic acid (32 R = Me) have been prepared and identified as constituents of the amine fraction of peyote. Acylation of 3,4-dimethoxyphenylpyruvic acid with anhydrides in the presence of perchloric acid yielded 2-benzopyrylium perchlorates (33), which were transformed into the corresponding isoquinolines (34) with ammonium acetate in glacial acetic acid. ... [Pg.121]

Procedures. The preparations of phenylpyruvic acid by the hydrolysis of o-acetaminocinnamic acid with 1 N hydrochloric acid and of 3,4-dimethoxyphenylpyruvic acid by the hydrolysis of a-benzoylamino-jS-(3,4-dimethoxyphenyl)-acrylic azlactone by 10%aqueous sodiumhydrox-ide are described in Organic Syntheses. ... [Pg.224]

Acylation of 3,4-dimethoxyphenylpyruvic methyl ester with acetic anhydride followed by acid-catalyzed cyclization provides a benzopyrylium salt. Further treatment with ammonia affords an isoquinoline derivative in good yield. ... [Pg.8]

See other pages where 3.4- Dimethoxyphenylpyruvic acid is mentioned: [Pg.48]    [Pg.34]    [Pg.229]    [Pg.18]    [Pg.50]    [Pg.53]    [Pg.48]    [Pg.34]    [Pg.229]    [Pg.18]    [Pg.50]    [Pg.53]   
See also in sourсe #XX -- [ Pg.33 ]

See also in sourсe #XX -- [ Pg.15 , Pg.33 ]

See also in sourсe #XX -- [ Pg.16 , Pg.33 ]

See also in sourсe #XX -- [ Pg.15 , Pg.33 ]

See also in sourсe #XX -- [ Pg.16 , Pg.33 ]



SEARCH



© 2024 chempedia.info