Carbon Dioxide → Benzopyran

HRID 1030830Notes

Reaction equation

HRID 1030830 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][CH:2]1O.C(=O)=O>S([O-])([O-])(=O)=O.[Cu+2]>[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]=[CH:3][CH2:2]1

Participants

4

Reactant 2

HCID 280Carbon DioxideHCID 11171070Chroman-2-ol

Product 1

HCID 9211BenzopyranYield 72%

Reagents, catalysts & solvents 1

HCID 24462Copper SulfateCatalyst

Procedure

A solution was prepared by dissolving 10 g (0.0318 mole) of 5-n-octyloxy-1-hydroxy-2-acetonaphthone, 2.77 g (0.0477 mole) of acetone and 1.13 g (0.0159 mole) of pyrrolidine 100 ml of toluene, and the solution was boiled for 10 hours and water was separated. After termination of the reaction, toluene was removed under reduced pressure, and the remaining chromanone compound was dissolved in 100 ml of methanol and sodium boron hydride was gradually added to the solution to form a chromanol compound. Then, 6.0 g of the chromanol compound was heated at 150° C. to 160° C. together with 4.0 g of anhydrous copper sulfate in a carbon dioxide current for 10 minutes. The obtained brown viscous liquid was purified by the chromatography on silica gel to obtain 3.8 g of a chromene compound represented by the following formula: ##STR255##

Workup

  1. customThe obtained brown viscous liquid was purified by the chromatography on silica gel

Sources & evidence

ORD record
ord-02e0ce3ae0e3429fb81a5e01ab73612b
Source dataset
uspto-grants-1992_04
Patent number
US05106998

Reaction notes

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