O-Aminoaryl- -aldehydes

FRIEOLANOER Quinoline Synthesis Quinoline synthesis from condensation of o aminoaryl aldehydes (ketones) with a methylene aldehydes (ketones)... 

The starting materials for this quinoline synthesis are o-aminoaryl aldehydes or ketones and a ketone possessing an a-methylene group. After an initial amino-ketone condensation, the intermediate undergoes base- or acid-catalyzed cyclocondensation to produce a quinoline derivative. 

The photodecomposition of 2,1-benzisothiazoles removes the sulfur atoms. In methanol, o-aminoaryl aldehydes or o-aminoaryl ketones are formed,40,120... 

A/ -Phenylimines can be used in place of the often unstable o-aminoaryl aldehydes or ketones. 

Cyclocondensation of o-aminoaryl ketones, or aldehydes with ketones possessing an a-CH2 group Friedlander synthesis) involves formation of o-aminocinnamoyl systems, e.g. 65 [99] ... 

Benzotriazines are ring-opened by aqueous acid at room temperature yielding o-aminobenz-aldehydes, whereas 4-substituted derivatives require heating to form <9-aminoaryl ketones. 1,2,3-Benzotriazin-4(37/)-ones 1 suffer acid cleavage of the heterocycle producing the diazonium ion 2 derived from anthranilic acid amide. Subsequent reactions of these ions involving the A-amino system 3 lead to the anthranilic acid azide 4 by an internal redox disproportionation ... 

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