New dikojyl aryl methanes

摘要

The invention comprises dikojyl-aryl methanes of the general formula wherein R1is an aryl radical substituted by one or more hydroxy and/or alkoxy or aralkoxy groups and optionally by one or more alkyl groups and R2, which may be the same or different, is hydrogen or an alkyl group. The compounds may be prepared by reacting one mole of an aromatic aldehyde R1CHO with two moles of kojic acid or a derivative thereof having the formula in the presence of a weak alkali e.g. NH4OH or KHCO3, as catalyst and if desired in the presence of a solvent, e.g. ethanol, R1 and R2 being as defined above, although where R1 represents an aryl radical containing one or more hydroxy groups, the latter one or more of them may be protected for example by benzylation and these protecting groups are removed after the reaction. The compounds may be used as anti-oxidants in oils, fats, methyl linoleate, linoleic acid and cod liver oil methyl esters. Examples describe the preparation of (1) dikojyl (o-hydroxy phenyl) methane; (2) dikojyl (p-hydroxy phenyl) methane; (3) dikojyl (2 - hydroxy - 5 - methoxyphenyl) methane; (4) di-(7-O-tert. butyl kojyl)(2-hydroxy-5-methoxyphenyl) methane; (5) dikojyl (2-hydroxy-5-benzyloxyphenyl) methane and its debenzylation by heating with acetic and hydrochloric acids; (6) di-(7-O-methyl kojyl)(2-hydroxy-5-ben-zyloxyphenyl) methane and its debenzylation by the method of (5); (7) dikojyl-(2-methoxy phenyl) methane; (8) dikojyl-(m-hydroxyphenyl) methane; (9) dikojyl (4 - hydroxy - 3 - methoxyphenyl) methane; (10) dikojyl-(3-hydroxy-4-methoxyphenyl) methane and (11) dikojyl (3:5-di-tert. butyl-4-hydroxyphenyl) methane. Most of these compounds are isolated as hydrates and are converted into poly-acetic esters by reaction with acetic anhydride in the presence of pyridine and the acetates are recovered as crystals containing one mole of ethanol.ALSO:Oils, fats and other lipids are stabilized against oxidation by means of dikojyl aryl methanes having the general formula wherein R1 is a phenyl or other aryl radical substituted by one or more hydroxy and/or alkoxy or aralkoxy groups and optionally by one or more alkyl groups and each R2, which may be the same or different, is hydrogen or alkyl.