Chemistry of carbon compounds – Miscellaneous organic carbon compounds – C-metal
Patent
1987-12-03
1989-09-19
Gray, Bruce
Chemistry of carbon compounds
Miscellaneous organic carbon compounds
C-metal
560142, 560109, 562897, C07C 6976
Patent
active
048679160
ABSTRACT:
Phenol sulphonate esters can be made in a known process by reacting an alkali metal phenol sulphonate salt with an acyl halide in a hydrocarbon solvent at elevated temperatures, but the use of anhydrous materials were strongly advocated because any residual water hydrolyses the acyl chloride in a competitive reaction. However, it becomes particularly difficult and expensive to dehydrate phenol sulphonate salts below about 2% w/w water on a commercial scale and the product obtained by reaction from such partly dehydrated salts can be comparatively impure or reduced in yield. Consequently, changes to the process such as omitting the solvent or using a different acylating agent have been proposed, but these alternatives introduce their own respective manufacturing problems such as entrainment of viscous acyl chloride and anhydride in the product or introduction of a cumbersome and hence expensive recovery process involving an extra distillation step amongst others.
The present invention provides a surprisingly convenient modification to the known process in which the esterification and product separation steps are incorporated into a cycle together with an acyl halide preparation step in which residual carboxylic acid and anhydride in solution after product separation is preferably augmented with a replenishing amount of carboxylic acid and then reacted with thiony halide. The resultant ester is readily separable and is obtained in comparatively good yield.
REFERENCES:
patent: 3925016 (1975-12-01), Haase
patent: 4587054 (1986-05-01), Hardy et al.
patent: 4588532 (1986-05-01), Moyne et al.
patent: 4704236 (1987-11-01), Sankey et al.
Pushel, Dr. F. and Todorov, Dr. O., "Connections between the Composition and Certain Properties of Surface Active Benzene Sulphonates with Heteroatoms in the Aliphatic Side Chain", Part 3: Preparation of Sulphonates, Tenside, 7, 1970, Heft 5, pp. 249-254, 1970; w/translation.
Sanderson William R.
Sankey John P.
Gray Bruce
Interox Chemicals Limited
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