GB669903A - A method of isolating lactams - Google Patents

A method of isolating lactams

Info

Publication number
GB669903A
GB669903A GB5522/49A GB552249A GB669903A GB 669903 A GB669903 A GB 669903A GB 5522/49 A GB5522/49 A GB 5522/49A GB 552249 A GB552249 A GB 552249A GB 669903 A GB669903 A GB 669903A
Authority
GB
United Kingdom
Prior art keywords
lactam
raw
lactams
superheated steam
vacuum
Prior art date
Legal status (The legal status 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 status listed.)
Expired
Application number
GB5522/49A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CHEMICKE ZD Y NA SLOVENSKU
Original Assignee
CHEMICKE ZD Y NA SLOVENSKU
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.)
Filing date
Publication date
Application filed by CHEMICKE ZD Y NA SLOVENSKU filed Critical CHEMICKE ZD Y NA SLOVENSKU
Publication of GB669903A publication Critical patent/GB669903A/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
    • C07D201/02—Preparation of lactams
    • C07D201/08—Preparation of lactams from carboxylic acids or derivatives thereof, e.g. hydroxy carboxylic acids, lactones or nitriles
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
    • C07D201/02—Preparation of lactams
    • C07D201/04—Preparation of lactams from or via oximes by Beckmann rearrangement
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
    • C07D201/16—Separation or purification
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D223/00—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom
    • C07D223/02—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings
    • C07D223/06—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
    • C07D223/08—Oxygen atoms
    • C07D223/10—Oxygen atoms attached in position 2

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Pyrrole Compounds (AREA)

Abstract

Lactams made by the Beckmann re-arrangement of cyclic ketoximes in hot sulphuric acid or oleum are isolated by treating the raw lactam with superheated steam and are subsequently separated by known methods, e.g. by crystallization or vacuum distillation. Steam treatment is preferably effected at reduced pressure which is not low enough to produce boiling of the lactam. The treatment removes impurities which cause turbidity in aqueous solutions of lactams and to prevent turbidity it is also necessary to neutralize the acid lactam solutions with an alkali other than ammonia. The raw lactam may contain water. In an example raw 6-caprolactam is treated with superheated steam at 120 DEG C. and 200 m.ms. Hg. until dry when the vacuum is increased to 8-10 m.ms. Hg. and the lactam distilled at 140 DEG C. Specification 666,717 is referred to.ALSO:Lastams made by the Beckmann rearrangement of cyclic ketoximes in hot sulphuric acid or oleum are isolated by treating the raw lactam with superheated steam and are subsequently separated by known methods, e.g. by crystallization or vacuum distillation. Steam treatment is preferably effected at reduced pressure which is not low enough to make the lactam boil. The treatment removes impurities which cause turbidity in aqueous solutions of lactams. The raw lactam may contain water. In an example raw 6-capiolactam is treated with superheated steam at 120 DEG C. and 200 m.ms. Hg. until dry when the vacuum is increased to 8-10 m.ms. Hg. and the lactam distilled at 140 DEG C.
GB5522/49A 1948-03-02 1949-03-01 A method of isolating lactams Expired GB669903A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CS669903X 1948-03-02

Publications (1)

Publication Number Publication Date
GB669903A true GB669903A (en) 1952-04-09

Family

ID=5454572

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5522/49A Expired GB669903A (en) 1948-03-02 1949-03-01 A method of isolating lactams

Country Status (1)

Country Link
GB (1) GB669903A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1022591B (en) * 1953-06-27 1958-01-16 Inventa A G Fuer Forschung & P Process for the purification of lactams of the ªÏ-aminocarboxylic acids
US2866785A (en) * 1958-12-30 Process for preconcentrating

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2866785A (en) * 1958-12-30 Process for preconcentrating
DE1022591B (en) * 1953-06-27 1958-01-16 Inventa A G Fuer Forschung & P Process for the purification of lactams of the ªÏ-aminocarboxylic acids

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