Process for Preparation of Resorcinol

This example illustrates the prior art where there is no solution of water and an alkali metal hydroxide added to the reaction products of step one prior to recovery by crystallization.

To a 12 L flask equipped with a stirrer, reflux condenser, N.sub.2 inlet, addition funnel, and heating mantle was added ethylene carbonate (1,936 g; 22 mole), resorcinol (1,101 g; 10 mole) and potassium carbonate (10 g; 0.07 mole). The apparatus was purged with N.sub.2 until the oxygen content was measured to be less than 1%. The mixture was stirred and gradually heated to 140.degree. C. When the temperature reached 40.degree. C., the stirring speed was increased to 100 rpm. At 125.degree. C., the mixture began to evolve CO.sub.2. The mixture was heated at 140.degree. C. for 6 hours, after which time it was cooled to 90.degree. C., and 4 L of water was added at a rate of 44 mL/min. while the temperature was maintained above 50.degree. C. The resulting mixture was stirred at 100 rpm and cooled to 50.degree. C. Resorcinol bis(hydroxyethyl)ether (2 g) was added as seed crystals and the mixture was cooled to 18.degree. C. at a rate of 5.degree./min. and held at this temperature for 1 hour. The product was collected by filtration, washed twice with 1 L portions of water, and dried in a vacuum oven at 50.degree. C. The yield was 1,366 g (69%) and contained an oily material which separated upon dissolving the material in warm water.

This example illustrates practice of the invention.

To a 1 L 3-neck flask equipped with a mechanical stirrer, heating mantle, reflux condenser, thermocouple well, and argon atmosphere, was added resorcinol (110 g; 1 mole), ethylene carbonate (194 g; 2.2 mole), and potassium carbonate (1 g; 7 "mmole"). The resulting mixture was heated at 140.degree. C. for 6 hours during which time CO.sub.2 was evolved. The mixture was cooled to 90.degree. C. and 400 mL of 4% NaOH solution was added over a 10 min. period while the temperature of the mixture was allowed to decrease to 53.degree. C. The mixture was allowed to slowly cool to 20.degree. C. to precipitate the resorcinol bis(hydroxyethyl)ether, and the resorcinol bis(hydroxyethyl)ether was collected by filtration, washed with 50 mL of water, and dried for 12 h in a vacuum oven. The dry product weighed 186 g (94%).

The invention was practiced by repeating Example 1 except 4 L of a sodium hydroxide solution was used in place of the 4 L of water. The presence of an oil-like by-product and the yield of resorcinol bis(hydroxyethyl)ether as a function of the concentration of NaOH used in the solution is summarized below.