Phenol-formaldehyde and allied resins. III. Further syntheses of resole molecules
| Autor: | A. T. Carpenter, R. F. Hunter |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Journal of Applied Chemistry. 3:486-495 |
| ISSN: | 1934-998X 0021-8871 |
| Popis: | Attempts to extend the lithium-exchange reaction for the synthesis of carboxydihydroxydiphenyl-methanes for subsequent reduction to resoles indicated that this method was likely to prove of very limited application. Attention was therefore directed to the syntheses of carboxy-derivatives of dihydroxydiphenylmethanes by means of side-chain oxidation of nuclear-methyl-substituted dimethoxydi-phenylmethanes, direct carbonation of dihydroxydiphenylmethanes, and condensation of bromomethyl-salicylic acid with phenols. Seven new resoles have been synthesized by lithium aluminium hydride reduction of carboxydihydroxydiphenylmethanes thus obtained and by further application of the method of halogen-blocking and subsequent dehalogenation. 5-Hydroxymethyl-2:2′-dihydroxydiphenylmethane and 3-hydroxymethyl-4:4′-dihydroxydiphenylmethane were synthesized by oxidation of 2:2′-dimethoxy-5-methyldiphenylmethane and 4:4′-dimethoxy-3-methylbenzophenone respectively, followed by demethylation, Clemmensen reduction of the carboxydihydroxybenzophenones and lithium aluminium hydride reduction of the resulting carboxydihydroxydiphenylmethanes. 3:3′-Bishydroxymethyl-4:4′-dihydroxydiphenylmethane and 3-hydroxymethyl-2:2′-dihydroxydiphenylmethane were synthesized by carbonation of 4:4′-dihydroxydiphenylmethane and 2:2′-dihydroxydiphenylmethane respectively and subsequent lithium aluminium hydride reduction. 2:2′-Dihydroxy-3:3′-bishydroxymethyldiphenylmethane was synthesized from 5:5′-dibromo-2:2′-dihydroxydiphenylmethane by way of 5:5′-dibromo-2:2′-dihydroxy-3:3′-bishydroxymethyldiphenylmethane and dehalogenation of the latter by palladium and hydrogen. 3-Hydroxymethyl-4:2′-dihydroxy-5′-methyldiphenylmethane was synthesized by condensation of 4-bromomethyl-2-carboxyphenol with p-cresol and subsequent reduction of the resulting 3-carboxy-4:2′-dihydroxy-5′-methyldiphenylmethane, and application of this reaction to p-bromophenol with subsequent dehalogenation of the 5′-bromo-3-carboxy-4:2′-dihydroxy-derivative furnished a synthesis of 4:2′-dihydroxy-3-hydroxymethyldiphenylmethane. |
| Databáze: | OpenAIRE |
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