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BERNTHSEN Acridine Synthesis

In the Bernthsen synthesis, diphenylamine 61 and carboxylic acids form 9-substituted acridines 62 (Scheme 31). [Pg.880]

Diphenylamine reacts with carboxylic acids in the presence of Lewis acids (e.g. AICI3, ZnCl2) forming 9-substituted acridines 20 (Bernthsen synthesis) ... [Pg.356]

Acridine dyes are amino derivatives of acridine. Acridine yellow G 40 is prepared by a similar method to pyronine G (see p 266) from 2,4-diaminotoluene via the leuco compound 39 by a Bernthsen synthesis. [Pg.359]

Ring closure y to a heteroatom is also a rather uncommon [5 + 1] procedure although there are some important exceptions. The most widely investigated is the Bernthsen acridine synthesis in which a diarylamine is condensed with a carboxylic acid in the presence of a Lewis acid (equation 73). More recently, it has been shown that acylanilines react with the Vilsmeier-Haack reagent to give quinolines in good yield (e.g. equation 74) and the mechanism of the reaction has been elucidated. A final example of [5 +1] ring closure y to a heteroatom which is of occasional use is the pyrazine synthesis outlined in equation (75). [Pg.78]

Many acridines and benzacridines have been synthesized by the Bernthsen reaction (l884LA(224)l) in which a diphenylamine is heated with a carboxylic acid and zinc chloride, with or without aluminum chloride. The reaction has been reviewed (73HC(9)141), and will be outlined here. The yields are not generally high one of the better examples is the synthesis of 2-chloro-9-methylacridine (312) (63BCJ1477). In the synthesis of the... [Pg.440]

BERNTHSEN Acridine Synthesis Acridine synthesis from diphenylamine and carboxylic acids (see 1st edition). [Pg.30]

BERNTHSEN Acridine synthesis Acridine synthesis from diphenylamme and carboxyfic acids... [Pg.20]

Acridines are an important structural feature of many natural products and medicinally important compounds. They can be produced in a straightforward manner by a Friedel-Crafts reaction, the Bernthsen acridine synthesis, 1 9 which couples diaryl amines (such as diphenylamine) with a carboxylic acid (such as benzoic acid) in the presence of a Lewis acid (zinc chloride, ZnCl2, is a typical reagent). Heating to 260°C (10 h) gave a 48% yield of acridine 317.1 9 ... [Pg.1107]

This reaction was first reported by Bernthsen in 1878It is one of the earliest methods for the synthesis of acridine by heating diphenylamine hydrochloride with benzonitrile. Therefore, this reaction is generally known as the Bernthsen reaction. In the modified method, the mixture of diphenylamine, an aromatic or aliphatic carboxylic acid, and zinc chloride is heated at 200-270°C for 20 Heating zinc chloride with fV-acyldiphenylamine or a mixture of diphenylamine and acyl chloride also affords acridines. ... [Pg.362]

Bernthsen Acridine Synthesis Thomas Andrew Wynn 7.2.1 Description... [Pg.360]


See other pages where BERNTHSEN Acridine Synthesis is mentioned: [Pg.662]    [Pg.319]    [Pg.44]    [Pg.319]    [Pg.362]    [Pg.122]   
See also in sourсe #XX -- [ Pg.662 ]




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