Tributylamine → 2H-1-Benzopyran-2-one, 4-chloro-6-methoxy-

HRID 1490256Notes

Reaction equation

HRID 1490256 reaction equation
O[C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([O:12][CH3:13])[CH:10]=2)[O:5][C:4](=[O:14])[CH:3]=1.O=P(Cl)(Cl)[Cl:17].C(N(CCCC)CCCC)CCC>C1(C)C=CC=CC=1>[Cl:17][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([O:12][CH3:13])[CH:10]=2)[O:5][C:4](=[O:14])[CH:3]=1

Participants

5

Reactant 3

HCID 7622TributylamineHCID 24813Phosphorus oxychlorideHCID 546765304-Hydroxy-6-methoxy-2H-1-benzopyran-2-one

Product 1

HCID 110850882H-1-Benzopyran-2-one, 4-chloro-6-methoxy-Yield 64%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A stirred mixture of 4-hydroxy-6-methoxycoumarin (116 g, 0.603 mole) and POCl3 (462.29 g, 3.015 mole) in toluene is treated dropwise with tri-n-butylamine (250 mL, 1.73 mole) at 25° C., heated at 100°-110° C. and monitored by HPLC analysis. When the reaction is complete, the mixture is cooled to room temperature, poured over ice, stirred mechanically for about 2 hours and filtered. The filtercake is washed with water and toluene, dissolved in methylene chloride and filtered through diatomaceous earth. The methylene chloride filtrate is concentrated and treated with a mixture of dimethylformamide and acetonitrile to afford crystallization. The mixture is filtered to give the title product, 81.7 g, (64% yield) identified by HPLC analysis.

Workup

  1. temperatureheated at 100°-110° C.
  2. additionpoured over ice
  3. filtrationfiltered
  4. washThe filtercake is washed with water and toluene
  5. dissolutiondissolved in methylene chloride
  6. filtrationfiltered through diatomaceous earth
  7. concentrationThe methylene chloride filtrate is concentrated
  8. additiontreated with a mixture of dimethylformamide and acetonitrile
  9. customto afford
  10. customcrystallization
  11. filtrationThe mixture is filtered

Sources & evidence

ORD record
ord-9f6a767d6fd04900b9e8fa4990e521f3
Source dataset
uspto-grants-1997_10
Patent number
US05681968

Reaction notes

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