Abstract: A process for the formation of a purified anhydrosugar alcohol is disclosed, whereby the resultant purified anhydrosugar alcohol has a purity of at least 99.8% and is substantially colorless. The anhydrosugar alcohol is purified by distillation, recrystallization from methanol, ethanol or ethylene glycol, melt recrystallization, or a combination thereof. Preferably, the purification is by distillation followed by recrystallization from methanol, ethanol or ethylene glycol. A test for determining the purity of the anhydrosugar alcohol is disclosed, wherein the color of the anhydrosugar alcohol after annealing at a temperature of at least 260° C. for at least four hours is examined. Alternatively, purity can be determined by examination of ultraviolet (UV) transmittance of the purified anhydrosugar alcohol at various wavelengths.

Abstract: A process is described for continuous production of anhydrosugar alcohol by continuous introducing of sugar alcohols and/or monoanhydrosugar alcohols into a reaction vessel and dehydration in the presence of an acid catalyst and solvent in which the resultant reaction product is soluble. Water and the solvent having the dissolved reaction product are each cointinuously removed from the reaction vessel. The reaction product is separated from the removed solvent and the product is optionally purified to a purity of 99.0% the solvent is recycled in the reaction vessel.

Abstract: A method is provided for purifying crude N-acetyl-para-aminophenol (APAP) containing color bodies or their precursors, the method comprising: a) forming a solution of the crude APAP; and b) subsequently contacting the solution with substoichiometric quantifies of an acetylating agent for a sufficient period of time to convert said color bodies or their precursors to substantially non-color bodies/stable, colorless substances; said quantities of acetylating agent provided is such that substantially none of the APAP is converted to other compounds.

Abstract: Ibuprofen is isolated from tablets or other solids by dissolving the ibuprofen in an alkane or cycloalkane solvent, filtering off undissolved solid, and stripping the solvent from the ibuprofen by evaporation or by recrystallization at low temperatures.

Abstract: This invention pertains to a method of purifying ibuprofen-comprising reaction product mixtures. The method of purification is based on crystallization of ibuprofen from a hydrocarbon solvent and the discovery that there are impurity complexes in the ibuprofen-comprising reaction product mixtures which cannot be removed by crystallization from a hydrocarbon solvent.The method of the invention includes at least one step in which the impurity complex in a first ibuprofen-comprising mixture is destabilized or broken up, followed by crystallization of the ibuprofen from a second solution or mixture comprising the first ibuprofen-comprising mixture, whereby the impurities which were previously complexed can then be removed from the ibuprofen by the crystallization of ibuprofen from a solvent.