Methylol derivatives Cresol

Thus methylene and ether links arise through competitive reactions. Ether formation will be favoured when there are few free o- and p- positions available for attack by carbonium ions. Thus when these active positions are blocked by non-reactive substituents or if complete methylolation has occurred (as in trimethylolphenol) then ether formation is to be expected. This is in accordance with the finding that treatment of the methylol derivative of p-t-butyl-o-cresol with dilute hydrochloric acid yields the corresponding dibenzyl ether [9] ... 

The most commonly known phenolic composite group is phenol formaldehyde polymers (phenoplasts). They are produced by polycondensation of a phenol and a mixture of phenols (phenol and phenol derivatives like cresol-resorcinol or para tertiary butyl phenol) with an aldehyde, usually formaldehyde and hexamethylene tetramine. Reaction of formaldehyde with phenol (up to 3 moles of formaldehyde can react with one mole of phenol - phenol acts as a three functional monomer) yields methylol groups in the ortho and para positions of the phenol molecule. In a further reaction, the methylol groups condenses with another molecule of phenol to form a methylene bridge. In practice, a prepolymer (usually a powder) is prepared first which is then cured later to the shape of the article in the mould. 

Meta-cresol, which has three positions capable of methylolation, is high reactive with formaldehyde, and the alcohols formed resinify rapidly even under alkaline conditions. As a result, it is extremely difficult to isolate pure phenol alcohols. However, crystalline products beliei ed to be monoalcohols and melting at 105, 110, 117, and 122 C have been reported . The difficulties of isolating pure products are considerable, since three monomethylol derivatives, three dimethylol derivatives and one trimethylol derivative are possible. 

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