O-Nitrobenz aldehyde

This reaction is particularly useful in the Fricdlander quinoline synthesis, the use of which has been limited hy the inaccessibility of o-aminobenzaldehydes. Thus a one-pot synthesis of quinolines is now possible by reduction of an o-nitrobenz-aldehyde with the reagent in the presence of an a-mcthylene ketone. 

Other aldehydes and related compounds have been reacted either alone or catalyzed with sulfuric acid, zinc chloride, magnesium chloride, ammonium chloride, or diammonium phosphate (94). Compounds such as l,3-bis(hydroxymethyl)-2-imidazolidone, glycol acetate, acrolein, chloroacetaldehyde, heptaldehyde, o- and p-chloro-benzaldehydes, furfural, p-hydroxybenzaldehyde, and m-nitrobenz-aldehyde all achieve the ASE by a bulking mechanism and not by low-level cross-linking. At weight gains of 15-25%, the highest ASE reported is 40%. 

The constitution (XXI) was confirmed by a synthesis of dl-cus-pareine, which was identical with the alkaloid in boiling point, in ultraviolet absorption spectrum, and in its sensitivity to hot mineral acid which caused reddening and resinification. dl-Norcuspareine (XXIV) was formed by the catalytic reduction of the products obtained by the condensation of veratric aldehyde with quinalcfine or with o-nitrobenzal-acetone, or of o-nitrobenzaldehyde with veratralacetone, and on methyla-... 

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