Salicylaldehyde, reaction with chloro

Salicylaldehyde, reaction with chloro-acetic acid, 46, 28... 

Dauzonne has reported a simple synthesis of flavanones by radical denitration and dehalo-genation of 3-chloro-2,3-dihydro-3-nitro-2-aryl-4T/- I-benzopyran-4-ones,92 which are readily prepared by the reaction of salicylaldehydes with l-chloro-l-nitro-2-arylethenes (Eq. 7.73).93... 

Cyclocondensation of 2-aminopyridines and methyl 2-chloro-3,5-dinitrobenzoate in boiling ethanol in the presence of sodium acetate for 12 h gave 8,10-dinitro-6//-pyrido[l,2-a]quinazolin-6-ones (312) [96JAP(K)96/157476]. 6//-Pyrido[l,2-a]quinazoline derivatives were prepared in the reaction of 2-aminopyridine and salicylaldehydes followed by treatment with NaBH4 (93MI7). 

Condensation of salicylaldehydes with 2-chloro-3-formylbutene and analogs gave 2-methylenechromcnc derivatives.227 The direct reaction of salicylaldehyde with 2-methyl-2-chlorobutane or 2-methylbutene with catalysts to give 2,2,3-trimethylchromene is reported in a patent228 The structure of the products from salicylaldehyde and dipheny-lenes229,230 has been revised, (see Section V,B).231... 

The Vilsmeier-Haack reaction (herein, Vilsmeier reaction ) provides an effective method for the formylation of aromatic systems. The combination of phosphoryl chloride with V-methylaniline or dimethylformamide generates an iminium phosphorus derivative or chloro-iminium cation that is the active electrophile in an electrophilic substitution reaction. The resulting substitution product is an iminium salt 1, which is hydrolyzed on workup with alkali to give the carbaldehyde product 2 (Scheme l).1,2 The method is particularly useful with activated arenes or electron-rich heterocycles, such as pyrroles, furans, thiophenes, and indoles. We had a special interest in the preparation of indole-7-carbal-dehydes, namely, their properties as isosteres of salicylaldehyde. Thus, we became involved in a wide-ranging investigation of 4,6-dimethoxy-... 

Salicylaldehydes give spirobenzo pyrans, often referred to simply as spiropyr-ans. In principle, true monocyclic spiropyrans would be prepared from 3-hydro-xyacrylaldehyde, which is the enol form of malonaldehyde. A reaction of Fischer s base with malonaldehyde or its chloro derivative gave complex mixtures containing the open form, but nitromalonaldehyde sodium salt gave with Fischer s base hydroiodide a 24% yield of beautiful orange crystals of the open form (3) (A. = 483 mm)7 Recently a series of 2-substituted malonaldehydes (4) became... 

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