| 摘要 |
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 -DIMETHYLBUTYRIC ACID; (D) PASSING THE SAID SOLUTION TO A SECOND REACTION CHAMBER AND MAINTAINING THE SOLUTION THEREIN AT SAID ELEVATED TEMPERATURE AND PRESSURE UNTIL THE alpha , gamma -DIHYDROXY- beta , beta -DIMETHYLBUTYRIC ACID IS LACTONIZED TO DL- alpha -hydroxy- beta , beta -dimethyl- gamma -butyrolactone and finally (E) RECOVERING THE LATTER PRODUCT FROM THE ACID SOLUTION.
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