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Class Information
Number: 548/555
Name: Organic compounds -- part of the class 532-570 series > Organic compounds (class 532, subclass 1) > 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) > Hetero ring is five-membered consisting of one nitrogen and four carbons (e.g., halopyrrolidines, etc.) > Chalcogen attached directly to the five-membered hetero ring by nonionic bonding (e.g., 3-pyrrolidinols, etc.) > Chalcogen bonded directly to a ring carbon of the five-membered hetero ring which is adjacent to the ring nitrogen (e.g., 2-pyrrolidones, etc.) > Purification or recovery of 2-pyrrolidone which is unsubstituted or alkyl substituted only
Description: Processes wherein 2-pyrrolidone, which is unsubstituted or alkyl substituted only, is separated from impurities, or from the reaction medium.
Patents under this class:
| Patent Number |
Title Of Patent |
Date Issued |
| 7138528 |
Method for crystallizing N-vinyl-2-pyrrolidone |
Nov. 21, 2006 |
| 7129376 |
Method for the production of a purified melt of at least one monomer |
Oct. 31, 2006 |
| 7037412 |
Method for preparing deodorized N-vinyl-2-pyrrolidone |
May. 2, 2006 |
| 6888006 |
Method for processing pyrollidone and n-vinyl pyrollidone residues |
May. 3, 2005 |
| 6726811 |
Method of purifying N-(2-hydroxyethy)-2-pyrrolidone |
Apr. 27, 2004 |
| 6703511 |
Method for obtaining pure n-vinyl pyrrolidone |
Mar. 9, 2004 |
| 6521097 |
Process for separating hydrogen chloride from a mixture comprising an N-alkyl-2-pyrrolidone and hydrogen chloride |
Feb. 18, 2003 |
| 6486169 |
Botanical drug for treatment and prevention of alzhimer's disease |
Nov. 26, 2002 |
| 6436243 |
Process for recovering N-vinyl-2-pyrrolidone |
Aug. 20, 2002 |
| 6417356 |
Stabilization of vinylether and vinyl lactam formulations against hydrolysis |
Jul. 9, 2002 |
| 6207824 |
Purification of N-substituted lactams |
Mar. 27, 2001 |
| 6051720 |
Removal of contaminants from N-methyl-2-pyrrolidone |
Apr. 18, 2000 |
| 5945544 |
Process for production of N-vinyllactam |
Aug. 31, 1999 |
| 5777131 |
Post manufacture process for improving the properties of lactones and substituted lactams |
Jul. 7, 1998 |
| 5710284 |
Purification of N-vinylpyrrolidone by crystallization |
Jan. 20, 1998 |
| 5462643 |
Method for reprocessing solvent mixtures containing constituents of low volatility and apparatus suitable therefor |
Oct. 31, 1995 |
| 5461159 |
Binding chemical impurities contained in crude N-vinylpyrrolid-2-one |
Oct. 24, 1995 |
| 5183538 |
Extraction plus ion exchange processing of a brine stream |
Feb. 2, 1993 |
| 5167775 |
Method for recovery of solvent used in production of polyarylene sulfide |
Dec. 1, 1992 |
| 5068358 |
Process for extracting N-methyl-2-pyrrolidone |
Nov. 26, 1991 |
| 5039817 |
Preparation of pure N-vinyl-2-pyrrolidone |
Aug. 13, 1991 |
| 4976825 |
Process for recovering N-methylpyrrolidone by plural distillations |
Dec. 11, 1990 |
| 4965370 |
N-methyl-2-pyrrolidone purification |
Oct. 23, 1990 |
| 4895959 |
Purification of N-methyl-2-pyrrolidone |
Jan. 23, 1990 |
| 4859781 |
Recovery of N-methyl-2-pyrrolidone |
Aug. 22, 1989 |
| 4837338 |
Removal of impurities from n-methyl-pyrrolidone using highly pure water washed activated alumina |
Jun. 6, 1989 |
| 4831160 |
Removal of volatile acids from NMP solvent vapors with sacrificial metal and ion exchange |
May. 16, 1989 |
| 4610768 |
Lactam purification |
Sep. 9, 1986 |
| 4552970 |
Solvated salts of dinitrophenylcyanamides, and a process for the preparation thereof |
Nov. 12, 1985 |
| 4510316 |
Purification of N-methylpyrrolidone |
Apr. 9, 1985 |
| 4501902 |
N-Methyl pyrrolidone-2 purification |
Feb. 26, 1985 |
| 4472585 |
Extraction of N-methylpyrrolidone-2 |
Sep. 18, 1984 |
| 4400521 |
N-Substituted phenyl maleimides |
Aug. 23, 1983 |
| 4384125 |
Process for the purification of 2-pyrrolidone |
May. 17, 1983 |
| 4316846 |
Recovery of aprotic amides |
Feb. 23, 1982 |
| 4276215 |
Purification of pyrrolidone |
Jun. 30, 1981 |
| 4216151 |
Process for the recovery of 2-pyrrolidone |
Aug. 5, 1980 |
| 4110340 |
Process for preparing lower lactams from allylic halide substrates |
Aug. 29, 1978 |
| 4050994 |
Recovery of 2-pyrrolidone from dilute alkaline solutions |
Sep. 27, 1977 |
| 4014754 |
Recovery of lactam solvent from vinyl polymer solution |
Mar. 29, 1977 |
| 4014900 |
Purification of 2-pyrrolidone |
Mar. 29, 1977 |
| 4013640 |
Process for the recovery of amides |
Mar. 22, 1977 |
| 4001274 |
Recovery of 2-pyrrolidone from aqueous solutions |
Jan. 4, 1977 |
| 3960846 |
Method for purifying lactams |
Jun. 1, 1976 |
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