DD278778A5 - Verfahren zur reinigung von 2-(4-isobutylphenyl)-propionsaeure - Google Patents

Verfahren zur reinigung von 2-(4-isobutylphenyl)-propionsaeure Download PDF

Info

Publication number: DD278778A5
Authority: DD; German Democratic Republic
Prior art keywords: rectification; isobutylphenyl; acid; propionic acid; carried out
Prior art date: 1988-01-29

Application number

DD89325298A

Other languages

German (de)

English (en)

Inventor

Siegbert Rittner

Adolf Schmidt

Larry O Wheeler

Gary L Moss

Edward G Zey

Original Assignee

��@��k��

��@��@��k��

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

1988-01-29

Filing date

1989-01-27

Publication date

1990-05-16

1989-01-27 Application filed by ��@��k��, ��@��@��k�� filed Critical ��@��k��

1990-05-16 Publication of DD278778A5 publication Critical patent/DD278778A5/de

Links

238000000034 method Methods 0.000 title claims abstract description 33
MDDHXQWPMRKRBD-UHFFFAOYSA-N 2-[4-(2-methylpropyl)phenyl]pentan-3-one Chemical class CCC(=O)C(C)C1=CC=C(CC(C)C)C=C1 MDDHXQWPMRKRBD-UHFFFAOYSA-N 0.000 title 1
238000004140 cleaning Methods 0.000 title 1
HEFNNWSXXWATRW-UHFFFAOYSA-N Ibuprofen Chemical compound CC(C)CC1=CC=C(C(C)C(O)=O)C=C1 HEFNNWSXXWATRW-UHFFFAOYSA-N 0.000 claims abstract description 14
RIOQSEWOXXDEQQ-UHFFFAOYSA-N triphenylphosphine Chemical compound C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 RIOQSEWOXXDEQQ-UHFFFAOYSA-N 0.000 claims description 38
239000012535 impurity Substances 0.000 claims description 24
239000000203 mixture Substances 0.000 claims description 22
238000000926 separation method Methods 0.000 claims description 12
238000000746 purification Methods 0.000 claims description 11
238000002425 crystallisation Methods 0.000 claims description 7
230000008025 crystallization Effects 0.000 claims description 7
239000002904 solvent Substances 0.000 claims description 5
239000000155 melt Substances 0.000 claims description 4
238000012856 packing Methods 0.000 claims description 4
VLVILBSSXMZZCB-UHFFFAOYSA-N 1-[4-(2-methylpropyl)phenyl]ethanol Chemical compound CC(C)CC1=CC=C(C(C)O)C=C1 VLVILBSSXMZZCB-UHFFFAOYSA-N 0.000 claims description 3
XBDQKXXYIPTUBI-UHFFFAOYSA-N Propionic acid Substances CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 claims description 3
239000004744 fabric Substances 0.000 claims description 3
239000011552 falling film Substances 0.000 claims description 3
239000011261 inert gas Substances 0.000 claims description 3
238000002360 preparation method Methods 0.000 claims description 3
239000010409 thin film Substances 0.000 claims description 3
UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 2
229910002091 carbon monoxide Inorganic materials 0.000 claims description 2
230000006315 carbonylation Effects 0.000 claims description 2
238000005810 carbonylation reaction Methods 0.000 claims description 2
229910052723 transition metal Inorganic materials 0.000 claims description 2
150000003624 transition metals Chemical class 0.000 claims description 2
239000002253 acid Substances 0.000 abstract description 46
239000000126 substance Substances 0.000 abstract description 5
238000000354 decomposition reaction Methods 0.000 abstract description 3
-1 amine salts Chemical class 0.000 abstract description 2
230000000202 analgesic effect Effects 0.000 abstract description 2
230000003356 anti-rheumatic effect Effects 0.000 abstract description 2
239000003435 antirheumatic agent Substances 0.000 abstract description 2
239000007864 aqueous solution Substances 0.000 abstract description 2
238000005260 corrosion Methods 0.000 abstract description 2
230000007797 corrosion Effects 0.000 abstract description 2
238000005520 cutting process Methods 0.000 abstract description 2
230000001754 anti-pyretic effect Effects 0.000 abstract 1
239000002221 antipyretic Substances 0.000 abstract 1
239000011541 reaction mixture Substances 0.000 description 10
238000009835 boiling Methods 0.000 description 8
IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
150000001875 compounds Chemical class 0.000 description 6
238000002844 melting Methods 0.000 description 6
230000008018 melting Effects 0.000 description 6
238000004821 distillation Methods 0.000 description 5
239000000047 product Substances 0.000 description 5
238000010992 reflux Methods 0.000 description 5
FIQMHBFVRAXMOP-UHFFFAOYSA-N triphenylphosphane oxide Chemical compound C=1C=CC=CC=1P(C=1C=CC=CC=1)(=O)C1=CC=CC=C1 FIQMHBFVRAXMOP-UHFFFAOYSA-N 0.000 description 5
239000013078 crystal Substances 0.000 description 4
239000007788 liquid Substances 0.000 description 4
239000000243 solution Substances 0.000 description 4
ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
238000001816 cooling Methods 0.000 description 3
238000010438 heat treatment Methods 0.000 description 3
VLKZOEOYAKHREP-UHFFFAOYSA-N hexane Substances CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
229910052757 nitrogen Inorganic materials 0.000 description 3
238000001953 recrystallisation Methods 0.000 description 3
XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
229910052799 carbon Inorganic materials 0.000 description 2
230000000052 comparative effect Effects 0.000 description 2
238000000605 extraction Methods 0.000 description 2
239000007789 gas Substances 0.000 description 2
229910052751 metal Inorganic materials 0.000 description 2
239000002184 metal Substances 0.000 description 2
150000003839 salts Chemical class 0.000 description 2
XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
SPBVCQUMYJRBMD-UHFFFAOYSA-N 1-(1-chloroethyl)-4-(2-methylpropyl)benzene Chemical compound CC(C)CC1=CC=C(C(C)Cl)C=C1 SPBVCQUMYJRBMD-UHFFFAOYSA-N 0.000 description 1
KEAGRYYGYWZVPC-UHFFFAOYSA-N 1-[4-(2-methylpropyl)phenyl]ethanone Chemical compound CC(C)CC1=CC=C(C(C)=O)C=C1 KEAGRYYGYWZVPC-UHFFFAOYSA-N 0.000 description 1
VTMSSJKVUVVWNJ-UHFFFAOYSA-N 1-ethenyl-4-(2-methylpropyl)benzene Chemical compound CC(C)CC1=CC=C(C=C)C=C1 VTMSSJKVUVVWNJ-UHFFFAOYSA-N 0.000 description 1
SFVKLYXPBKITCE-UHFFFAOYSA-N 2-[3-(2-methylpropyl)phenyl]propanoic acid Chemical compound CC(C)CC1=CC=CC(C(C)C(O)=O)=C1 SFVKLYXPBKITCE-UHFFFAOYSA-N 0.000 description 1
DYNVRFFVBZVRND-UHFFFAOYSA-N 3-[4-(2-methylpropyl)phenyl]propanoic acid Chemical compound CC(C)CC1=CC=C(CCC(O)=O)C=C1 DYNVRFFVBZVRND-UHFFFAOYSA-N 0.000 description 1
MAUAHKQOJAFLQH-UHFFFAOYSA-N 4-methylpentan-2-ylbenzene Chemical compound CC(C)CC(C)C1=CC=CC=C1 MAUAHKQOJAFLQH-UHFFFAOYSA-N 0.000 description 1
OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
229910019142 PO4 Inorganic materials 0.000 description 1
150000007513 acids Chemical class 0.000 description 1
150000001298 alcohols Chemical class 0.000 description 1
238000004458 analytical method Methods 0.000 description 1
229910052786 argon Inorganic materials 0.000 description 1
230000015572 biosynthetic process Effects 0.000 description 1
239000006227 byproduct Substances 0.000 description 1
239000001569 carbon dioxide Substances 0.000 description 1
229910002092 carbon dioxide Inorganic materials 0.000 description 1
150000001735 carboxylic acids Chemical class 0.000 description 1
150000001805 chlorine compounds Chemical class 0.000 description 1
239000002131 composite material Substances 0.000 description 1
239000000356 contaminant Substances 0.000 description 1
238000002845 discoloration Methods 0.000 description 1
239000003814 drug Substances 0.000 description 1
230000032050 esterification Effects 0.000 description 1
238000005886 esterification reaction Methods 0.000 description 1
HXTFUVWJFLDLJP-UHFFFAOYSA-N ethyl 2-[4-(2-methylpropyl)phenyl]propanoate Chemical compound CCOC(=O)C(C)C1=CC=C(CC(C)C)C=C1 HXTFUVWJFLDLJP-UHFFFAOYSA-N 0.000 description 1
238000002474 experimental method Methods 0.000 description 1
239000000284 extract Substances 0.000 description 1
239000011521 glass Substances 0.000 description 1
150000002500 ions Chemical class 0.000 description 1
KXUHSQYYJYAXGZ-UHFFFAOYSA-N isobutylbenzene Chemical compound CC(C)CC1=CC=CC=C1 KXUHSQYYJYAXGZ-UHFFFAOYSA-N 0.000 description 1
150000002576 ketones Chemical class 0.000 description 1
238000004519 manufacturing process Methods 0.000 description 1
238000010327 methods by industry Methods 0.000 description 1
230000007935 neutral effect Effects 0.000 description 1
235000021317 phosphate Nutrition 0.000 description 1
150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
239000012264 purified product Substances 0.000 description 1
229920005989 resin Polymers 0.000 description 1
239000011347 resin Substances 0.000 description 1
159000000000 sodium salts Chemical class 0.000 description 1
238000007711 solidification Methods 0.000 description 1
230000008023 solidification Effects 0.000 description 1
238000001179 sorption measurement Methods 0.000 description 1
239000007858 starting material Substances 0.000 description 1
150000003440 styrenes Chemical class 0.000 description 1
238000003786 synthesis reaction Methods 0.000 description 1
239000002351 wastewater Substances 0.000 description 1
238000010626 work up procedure Methods 0.000 description 1

Classifications

- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C57/00—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms
- C07C57/30—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms containing six-membered aromatic rings
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
- C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation

Landscapes

Chemical & Material Sciences (AREA)
Organic Chemistry (AREA)
Crystallography & Structural Chemistry (AREA)
Engineering & Computer Science (AREA)
Oil, Petroleum & Natural Gas (AREA)
Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

DD89325298A 1988-01-29 1989-01-27 Verfahren zur reinigung von 2-(4-isobutylphenyl)-propionsaeure DD278778A5 (de)

Applications Claiming Priority (1)

Application Number	Priority Date	Filing Date	Title
DE3802619A DE3802619C1 (fr)	1988-01-29	1988-01-29

Publications (1)

Publication Number	Publication Date
DD278778A5 true DD278778A5 (de)	1990-05-16

Family

ID=6346221

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
DD89325298A DD278778A5 (de)	1988-01-29	1989-01-27	Verfahren zur reinigung von 2-(4-isobutylphenyl)-propionsaeure

Country Status (22)

Country	Link
EP (1)	EP0326027B1 (fr)
JP (1)	JP2688515B2 (fr)
KR (1)	KR0129753B1 (fr)
CN (1)	CN1025609C (fr)
AR (1)	AR244196A1 (fr)
AT (1)	ATE83766T1 (fr)
AU (1)	AU607837B2 (fr)
CA (1)	CA1337553C (fr)
DD (1)	DD278778A5 (fr)
DE (2)	DE3802619C1 (fr)
DK (1)	DK175685B1 (fr)
ES (1)	ES2042811T3 (fr)
FI (1)	FI90656C (fr)
GR (1)	GR3007235T3 (fr)
HU (1)	HU202172B (fr)
IE (1)	IE63324B1 (fr)
IL (1)	IL89094A (fr)
NO (1)	NO169118C (fr)
NZ (1)	NZ227756A (fr)
PT (1)	PT89535B (fr)
RU (1)	RU1819257C (fr)
ZA (1)	ZA89619B (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE3833446A1 (de) *	1988-10-01	1990-04-05	Hoechst Ag	Verfahren zur herstellung von arzneimittelwirkstoff-partikeln mit verbesserten fliess-, lager- und formulierungseigenschaften sowie arzneimittel, die diese arzneimittelwirkstoff-partikeln enthalten
DE3833448A1 (de) *	1988-10-01	1990-04-12	Hoechst Ag	Verfahren zur gewinnung von ibuprofen fuer die direkttablettierung
US5151551A (en) *	1990-09-06	1992-09-29	Hoechst Celanese Corporation	Method for purification of ibuprofen comprising mixtures
GB0519350D0 (en)	2005-09-22	2005-11-02	Boots Healthcare Int Ltd	Therapeutic agents
CN204505103U (zh) *	2015-04-14	2015-07-29	杭州巨星科技股份有限公司	蜗轮夹持防松结构及防松活络扳手

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
GB971700A (en) *	1961-02-02	1964-09-30	Boots Pure Drug Co Ltd	Anti-Inflammatory Agents
US3344045A (en) *	1964-10-23	1967-09-26	Sun Oil Co	Electrolytic preparation of carboxylic acids
HU173576B (hu) *	1975-06-24	1979-06-28	Chinoin Gyogyszer Es Vegyeszet	Sposob poluchenija zamehhjonnykh fenil-alkil-karbonovykh kislot
DE2557011A1 (de) *	1975-12-18	1977-06-23	Dynamit Nobel Ag	Verfahren zur herstellung von alpha- arylsubstituierten propionsaeurealkylestern
US4694100A (en) *	1984-07-14	1987-09-15	Nippon Petrochemicals Company, Ltd.	Method for producing α-(p-isobutylphenyl)propionic acid or its alkyl esters

1988
- 1988-01-29 DE DE3802619A patent/DE3802619C1/de not_active Expired
1989
- 1989-01-20 EP EP89100912A patent/EP0326027B1/fr not_active Expired - Lifetime
- 1989-01-20 ES ES89100912T patent/ES2042811T3/es not_active Expired - Lifetime
- 1989-01-20 DE DE8989100912T patent/DE58903057D1/de not_active Expired - Fee Related
- 1989-01-20 AT AT89100912T patent/ATE83766T1/de not_active IP Right Cessation
- 1989-01-26 PT PT89535A patent/PT89535B/pt active IP Right Grant
- 1989-01-26 FI FI890386A patent/FI90656C/fi active IP Right Grant
- 1989-01-26 ZA ZA89619A patent/ZA89619B/xx unknown
- 1989-01-26 AR AR89313081A patent/AR244196A1/es active
- 1989-01-27 NZ NZ227756A patent/NZ227756A/en unknown
- 1989-01-27 DK DK198900376A patent/DK175685B1/da not_active IP Right Cessation
- 1989-01-27 CN CN89101467A patent/CN1025609C/zh not_active Expired - Fee Related
- 1989-01-27 KR KR1019890000868A patent/KR0129753B1/ko not_active Expired - Fee Related
- 1989-01-27 CA CA000589392A patent/CA1337553C/fr not_active Expired - Fee Related
- 1989-01-27 NO NO890344A patent/NO169118C/no unknown
- 1989-01-27 IE IE26889A patent/IE63324B1/en not_active IP Right Cessation
- 1989-01-27 AU AU28857/89A patent/AU607837B2/en not_active Ceased
- 1989-01-27 IL IL89094A patent/IL89094A/xx not_active IP Right Cessation
- 1989-01-27 HU HU89418A patent/HU202172B/hu not_active IP Right Cessation
- 1989-01-27 JP JP1016525A patent/JP2688515B2/ja not_active Expired - Fee Related
- 1989-01-27 DD DD89325298A patent/DD278778A5/de unknown
- 1989-01-28 RU SU894613357A patent/RU1819257C/ru not_active IP Right Cessation
1993
- 1993-03-05 GR GR930400198T patent/GR3007235T3/el unknown

Also Published As

Publication number	Publication date
CN1035821A (zh)	1989-09-27
KR890011816A (ko)	1989-08-22
NZ227756A (en)	1992-05-26
GR3007235T3 (fr)	1993-07-30
DK37689D0 (da)	1989-01-27
HU202172B (en)	1991-02-28
ES2042811T3 (es)	1993-12-16
IE63324B1 (en)	1995-04-05
CA1337553C (fr)	1995-11-14
FI890386L (fi)	1989-07-30
DK37689A (da)	1989-07-30
PT89535A (pt)	1989-10-04
FI890386A0 (fi)	1989-01-26
AR244196A1 (es)	1993-10-29
AU2885789A (en)	1989-08-03
FI90656C (fi)	1994-03-10
NO169118C (no)	1992-05-13
FI90656B (fi)	1993-11-30
NO169118B (no)	1992-02-03
DE58903057D1 (de)	1993-02-04
EP0326027B1 (fr)	1992-12-23
PT89535B (pt)	1994-02-28
IL89094A (en)	1993-02-21
NO890344D0 (no)	1989-01-27
DE3802619C1 (fr)	1989-09-07
KR0129753B1 (ko)	1998-04-07
IL89094A0 (en)	1989-08-15
JP2688515B2 (ja)	1997-12-10
CN1025609C (zh)	1994-08-10
RU1819257C (en)	1993-05-30
NO890344L (no)	1989-07-31
DK175685B1 (da)	2005-01-17
EP0326027A1 (fr)	1989-08-02
JPH01226848A (ja)	1989-09-11
ATE83766T1 (de)	1993-01-15
ZA89619B (en)	1989-09-27
IE890268L (en)	1989-07-29
AU607837B2 (en)	1991-03-14

Legal Events

Date	Code	Title	Description
2004-04-28	IF04	In force in the year 2004	Expiry date: 20090128

Publication	Publication Date	Title
DE4308087C2 (de)	1997-02-06	Verfahren zur Abtrennung von Acrylsäure aus den Reaktionsgasen der katalytischen Oxidation von Propylen und/oder Acrolein
DE69521230T2 (de)	2001-10-11	Herstellung von alpha-beta-ungesättigten C3-C6-Carbonsäuren
EP0792867A2 (fr)	1997-09-03	Procédé de purification de l'acide acrylique et méthacrylique
AT404832B (de)	1999-03-25	Verfahren zur kristallisation von iopamidol
EP2334631B1 (fr)	2017-03-01	Procede de separation de l'acide acrylique contenu comme constituant principal, et de glyoxal contenu comme produit secondaire d'un melange de gaz de produit d'une oxydation en phase gazeuse partielle par catalyse heterogene d'un compose precurseur en c3 d'acide acrylique
DE3428319A1 (de)	1986-02-13	Verfahren zur gewinnung wasserfreier bzw. weitgehendwasserfreier ameisensaeure
EP0017866A1 (fr)	1980-10-29	Procédé de préparation d'acide formique entièrement ou substantiellement anhydre
DE102008040799A1 (de)	2008-12-11	Verfahren zur Auftrennung von in einem Produktgasgemisch einer partiellen heterogen katalysierten Gasphasenoxidation einer C3-Vorläuferverbindung der Acrylsäure als Hauptbestandteil enthaltener Acrylsäure und als Nebenprodukt enthaltenem Glyoxal
DE2643000A1 (de)	1977-03-31	Reinigung von alkansulfonsaeuren durch destillation
DE2505471B2 (de)	1978-08-03	Verfahren zur "Gewinnung von Essigsäureanhydrid durch kontinuierliche fraktionierte Destillation von Rohessigsäureanhydrid
EP2059493A1 (fr)	2009-05-20	Recuperation de ligands phenol lors de la production d'isopulegol
EP0636620B1 (fr)	1997-10-15	Procédé d'obtention d'éthylène glycol-carbonate purifié
DE2547540A1 (de)	1976-05-13	Verfahren zur herstellung von hydroxypivaldehyd
DE69417728T2 (de)	1999-10-21	Verfahren zur herstellung von reinem vinyl pyrrolidon
EP0242778B1 (fr)	1989-09-13	Séparation de diastéréo-isomères
DE69114486T2 (de)	1996-03-21	Verfahren zur Reinigung von Glycidyl(meth)acrylat.
DE69106972T2 (de)	1995-07-20	Hochreines 1-Aminopropandiol-2,3 und Verfahren zur Reinigung dieser Verbindung.
DE3037476A1 (de)	1981-04-23	Verfahren zur trennung von resorcin und hydrochinon voneinander bzw. zur abtrennung und reinigung von hydrochinon aus verunreinigtem rohhydrochinon
EP0326027B1 (fr)	1992-12-23	Procédé de purification d'acide 2-(4-isobutylphényl)-propionique
DE2003684C3 (de)	1979-11-29	Kontinuierliches Verfahren zur Herstellung von Maleinsäureanhydrid aus einer wäßrigen Maleinsäurelösung
DE69204493T2 (de)	1996-03-21	Verfahren zur Reinigung von Dimethylcarbonat.
DE69501120T2 (de)	1998-03-26	Verfahren zur Gewinnung von Dipropylenglykol-Tert-Butylethern
EP1415964B1 (fr)	2013-02-13	Procédé pour la séparation de mélanges contenant du m- et p-dichlorobenzène
EP1309574B1 (fr)	2005-06-08	Procede de purification de 2-chloro-5-chloromethylthiazole
DE1695247C3 (de)	1975-05-28	Verfahren zur Reinigung von Lactamen durch Schmelzkristallisation