Dicarboxylate esters of alcohol containing a quaternary carbon in the beta-position

Abstract

Abstract Hydraulic fluids, heat transfer fluids or synthetic lubricants comprise a diester of a saturated aliphatic, saturated cycloaliphatic or aromatic dicarboxylic acid having up to eleven carbon atoms in the molecule and one or two monohydric primary alcohols, which alcohols are free from aliphatic unsaturation, have from five to sixteen carbon atoms and have a quaternary carbon atom in the betaposition, together with a silicate, a hexaalkoxy disiloxane, a silicone, a phosphate ester or a mineral oil base. The diesters may comprise a major or a minor proportion of the mixture.ALSO:The invention comprises a diester of a saturated aliphatic, saturated cycloaliphatic or aromatic dicarboxylic acid having up to eleven carbon atoms in the molecule and one or two monohydric primary alcohols, which alcohols are free from aliphatic unsaturation, have from five to sixteen carbon atoms and have a quaternary carbon atom in the beta-position. A preferred class of alcohols are those of the formula R1.C(R2)(R3).CH2.OH, in which R1, R2 and R3 are all alkyl groups, preferably n-alkyl groups. Another preferred group of alcohols is that in which the beta-carbon atom is part of a cycloalkyl group containing five or six carbon atoms. The compounds may be prepared by the usual esterification procedures, e.g. by heating the acid or acid halide with a slight excess of the alcohol using sulphuric acid as an esterification catalyst, and removing water azeotropically by distilling in the presence of toluene. An alternative procedure involves ester interchange using an ester of the dicarboxylic acid with an alcohol of low molecular weight, such as methanol, in the presence of a catalyst. The esters find use in hydraulic fluids, heat transfer fluids or synthetic lubricants (see Group III). Detailed examples of the preparation of diesters are given. One example also describes the preparation of 2,2,4-trimethyl-1-pentanol by reacting 2,2,4-trimethyl-1,3-pentanediol with acetyl chloride to form 2,2,4-trimethyl-1,3-diacetoxypentane, selectively pyrolysing the latter to form 2,2,4-trimethyl-3-penten-1-yl-acetate, and then reducing the acetate using hydrogen with a palladium on carbon catalyst to form the 2,2,4-trimethyl-1-pentanol.

Inventors

• 👤 Edward S Blake
• 👤 William C Hammann

Bibliographic Details