Chelidonic acid → 1-Cyclopropyl-4-pyridone

HRID 2118595Notes

Reaction equation

HRID 2118595 reaction equation
C([C:4]1O[C:6](C(O)=O)=[CH:7][C:8](=[O:10])[CH:9]=1)(O)=O.[CH:14]1([NH2:17])[CH2:16][CH2:15]1>CO>[CH:14]1([N:17]2[CH:4]=[CH:9][C:8](=[O:10])[CH:7]=[CH:6]2)[CH2:16][CH2:15]1

Participants

4

Reactant 2

HCID 7431Chelidonic acidHCID 69828Cyclopropylamine

Product 1

HCID 152725471-Cyclopropyl-4-pyridone

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

The starting material may be obtained as follows. A solution of 2,6-dicarboxy-4-pyrone (10.0 g.) and cyclopropylamine (3.8 ml.) in MeOH (300 ml.) was stirred at room temperature overnight. The precipitated salt was filtered off, dried under vacuum and heated to 200° for 30 minutes. The resulting black gum was extracted with methylene chloride (3×150 ml.). The extracts were concentrated and purified by chromatography on Kieselgel 60 (100 g.) using methylene chloride/MeOH 100:0 to 80:20 v/v to give 1-cyclopropyl-4-pyridone (1.26 g.) as an oil having n.m.r. in CDCl3 : 1.03(m, 4H); 3.38(m, 1H); 6.3(d, 2H); 7.4(d, 2H). This material was chlorinated as described in the second part of Example 56 to give 4-chloro-1-cyclopropylpyridinium toluene-p-sulphonate.

Workup

  1. customThe starting material may be obtained
  2. filtrationThe precipitated salt was filtered off
  3. customdried under vacuum
  4. temperatureheated to 200° for 30 minutes
  5. extractionThe resulting black gum was extracted with methylene chloride (3×150 ml.)
  6. concentrationThe extracts were concentrated
  7. custompurified by chromatography on Kieselgel 60 (100 g.)

Sources & evidence

ORD record
ord-ba9257dba81140dfba9c5fd477cc2e95
Source dataset
uspto-grants-1987_07
Patent number
US04678781

Reaction notes

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