Abstract: DL pantolactone is made by(a) introducing isobutyraldehyde, formalin and sodium cyanide solution continuously at a predetermined rate into a circulation reactor, continuously circulating the said mixture in said reactor while cooling the circulating mass in a heat exchanger, thus continuously causing the heat generated in the reaction between the components of said mixture to be discharged in said heat exchanger and by continuously re-mixing the formed reaction product with the reaction components;(b) continuously passing part of the reaction product into an after-treatment reactor where the said reaction is completed without re-mixing so as to form formisobutyraldolcyanohydrin;(c) passing the latter product into a first reaction chamber, reacting therein the product with a continuously introduced non-oxidizing strong acid at an elevated temperature and pressure so as to hydrolyze the product, thus forming a solution of .alpha.,.gamma.-dihydroxy-.beta.,.beta.

Abstract: A process for the resolution of optical isomers of racemic lithium pantoate by selective crystallization from a solution in methanol, ethanol, or other polar solvents, or by electrostatic separation. The optical isomers can be readily converted to optically active pantolactones which are the starting material for the preparation of optically active pantothenic acid and its salt and pantothenyl alcohol. One of the two optical isomers of each of these compounds possesses vitamin activity. The unwanted or inactive optical isomer of lithium pantoate as such is thermally stable and can be racemized by heating in the presence of a basic reacting compound at a temperature between 120 and 180.degree. C to produce a racemic mixture which can then be subjected directly to resolution without conversion to some other derivative in accordance with the processes of the present invention to produce the desired or active optical isomer.

Abstract: A process for the resolution of optical isomers of racemic lithium pantoate by selective crystallization from a solution in methanol, ethanol, or other polar solvents, or by electrostatic separation. The optical isomers can be readily converted to optically active pantolactones which are the starting material for the preparation of optically active pantothenic acid and its salt and pantothenyl alcohol. One of the two optical isomers of each of these compounds possesses vitamin activity. The unwanted or inactive optical isomer of lithium pantoate as such is thermally stable and can be racemized by heating in the presence of a basic reacting compound at a temperature between 120.degree. and 180.degree. C to produce a racemic mixture which can then be subjected directly to resolution without conversion to some other derivative in accordance with the processes of the present invention to produce the desired or active optical isomer.

Abstract: An apparatus for making DL-pantolactone in a continuous process comprises the following parts and setup:A circulation heater and a circulation reactor, means for introducing the components into the reactor, a heat-exchanger forming part of the circulation reactor, a longitudinal aftertreatment reactor and a final longitudinal reactor comprising dual reaction chambers with means for applying heat and pressure in the first chamber and maintaining the reaction product in the second chamber at such heat and pressure. The apparatus may also include a chamber for forming a premix of some of the components with a subsequent cooling device prior to the introduction into the circulation reactor. It may furthermore include a stripping column and pulsation column for recovering the final product from the solution.

Abstract: The method comprises preheating a cyanide solution to be detoxified by passing the cyanide solution through a heat exchanger and initiating a detoxifying hydrolysis of the cyanide solution by subjecting the cyanide solution to a temperature shock raising the temperature of the cyanide solution to between about 200.degree. and 250.degree. C and passing the cyanide solution through a tubular reactor at a pressure of between about 40 and 140 atm.