• Ram Ghulam Singh Nigam

      Articles written in Proceedings – Section A

    • Condensation of aldehydes with amides - Part XVII. Of 5-chloro- and 3 ∶ 5-dichlorosalicylaldehydes

      Ram Ghulam Singh Nigam Kantilal C Pandya

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      5-Chloro- and 3 ∶ 5-dichlorosalicylaldehydes have been condensed with different amides under different conditions. In contrast with the_-mono-amides obtained in all the salicylaldehyde-amide condensations,7 the monochlorosalicylaldehyde gave monoamides with only three amides, of which one, benzamide, gave the bis- product as well. The 3 ∶ 5-dichlorosalicylaldehyde gave the monoamide only once, in its condensation with benzenesulphonamide: for all the rest the-bis product was the usual rule. This may be one of the effects of the chlorine on the aromatic ring of the aldehyde. Except in one case the yields in the dichlorosalicylaldehyde-amides condensations were all higher than those of the monochloro-aldehyde-amide condensations, reaching, in condensations with propionamide and benzenesulphonamide, the quantitative limits. Usually the highest yields were obtained at 100–110° and in the absence of any condensing agent.

    • Condensation of aldehydes with amides - Part XVII. Of 5-chloro- and 3 ∶ 5-dichlorosalicylaldehyde addendum

      Ram Ghulam Singh Nigam Kantilal C Pandya

      More Details Abstract Fulltext PDF

      Salicylaldehyde-amide condensations always produced the salicylidene-monoamides and the highest yield was always obtained in the presence of pyridine.7 The 5-chlorosalicylaldehyde and the 3 ∶ 5-dichlorosalicylaldehyde gave the best yield usually when heated alone; the product was almost always the-bis in the case of the latter, and generally so in the case of the former. The condensations with cinnamamide gave a quicker and a higher yield, it being quantitative in the case of the dichlorosalicylaldehyde. As before a temperature slightly higher than that of the water-bath produced generally a better yield in the last two amide condensations.

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