Patent GB-894639-A (GB)
Title: Improvements relating to the preparation of esters
IPC: B01J27/00
Filed: 1959-05-15
Abstract: Complex esters are prepared by esterifying in one or more stages (a) either (i) a monohydric alcohol or mixture of such alcohols or (ii) an aliphatic monocarboxylic acid or mixture of such acids, (b) an aliphatic dicarboxylic acid or mixture of such acids, and (c) a diol or mixture of such diols, in the presence of an alkali metal pyrosulphate as esterification catalyst. Esterification may be effected by: (i) refluxing all the reactants together; (ii) refluxing the diol and dicarboxylic acid together, the product being subsequently refluxed with alcohol or monocarboxylic acid; (iii) refluxing the alcohol and dicarboxylic acid together, the product being subsequently refluxed with diol; (iv) refluxing the monocarboxylic acid and diol together, the product being subsequently refluxed with dicarboxylic acid.  In examples: (1) adipic acid, sebacic acid, neopentyl glycol and iso-octanol are reacted as in method (ii) above in the presence of benzene and (a) no catalyst, (b) sodium bisulphate, or (c) potassium pyrosulphate; (2) 3:5:5-trimethyl-hexanol, sebacic acid, adipic acid and neopentyl glycol are reacted as in method (i) above in the presence of benzene and (a) no catalyst, (b) sodium bisulphate, or (c) potassium pyrosulphate.  Other reactants specified are: C8-C18 alcohols, e.g. 2-ethylhexanol, 2:2:4-trimethylpentanol and iso-tridecanol (as prepared by the oxo process); C8-C10 acids, e.g. pelargonic and 2-ethylhexanoic acid; azelaic acid; ethylene glycol, propylene glycol and polyethylene glycol 200.  Specification 687,348 is referred to.ALSO:Complex esters are prepared by esterifying in one or more stages (a) either (i) a monohydric alcohol or mixture of such alcohols or (ii) an aliphatic monocarboxylic acid or mixture of such acids, (b) an aliphatic dicarboxylic acid or mixture of such acids, and (c) a diol or mixture of diols, in the presence of an alkali metal pyrosulphate as esterification catalyst. Esterification may be effected by (i) refluxing all the reactants together; (ii) refluxing the diol and dicarboxylic acid together, the product being subsequently refluxed with alcohol or monocarboxylic acid; (iii) refluxing the alcohol and dicarboxylic acid together, the product being subsequently refluxed with diol; or (iv) refluxing the monocarboxylic acid and diol together, the product being subsequently refluxed with dicarboxylic acid.  In examples (i) adipic acid, sebacic acid, neopentyl glycol and iso-octanol are reacted as in method (ii) above in the presence of benzene and (a) no catalyst, (b) sodium bisulphate, or (c) potassium pyrosulphate; (2) 3 : 5 : 5-trimethylhexanol, sebacic acid, adipic acid and neopentyl glycol are reacted as in method (i) above in the presence of benzene and (a) no catalyst, (b) sodium bisulphate, or (c) potassium pyrosulphate. Other reactants specified are C8-C18 alcohols, e.g. 2-ethylhexanol, 2 : 2 : 4-trimethylpentanol, and iso-tridecanol (as produced by the oxo process); C8-C10 acids, e.g. pelargonic acid and 2-ethylhexanoic acid; azelaic acid; ethylene glycol, propylene glycol and polyethylene glycol 200.  Specification 687,348 is referred to.