US PATENT SUBCLASS 546 / 353
.~.~.~.~ Purification or recovery


Current as of: June, 1999
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546 /   HD   ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES

*  DD  ORGANIC COMPOUNDS (Class 532, Subclass 1) {1}
*  DD  .~ HETEROCYCLIC CARBON COMPOUNDS CONTAINING A HETERO RING HAVING CHALCOGEN (I.E., OXYGEN, SULFUR, SELENIUM, OR TELLURIUM) OR NITROGEN AS THE ONLY RING HETERO ATOMS (Class 540, subclass 1) {1}
1  DF  .~.~ Hetero ring is six-membered consisting of one nitrogen and five carbons {24}
348  DF  .~.~.~ Unsubstituted or hydrocarbyl substituted only, or salt thereof {3}
353.~.~.~.~ Purification or recovery


DEFINITION

Classification: 546/353

Purification or recovery:

(under subclass 348) Processes wherein the unsubstituted or hydrocarbyl substituted pyridine is separated from impurities or from the reaction medium.

(1) Note. This subclass provides for such processes as the vapor phase separation or 2,6-lutidine from beta- and gamma-picolines, the separation of aromatic pyridines using alkylene carbonates, the recovery of pyridine bases, the purification of 3-picoline, etc.