Carbon Dioxide → Benzopyran

HRID 1030828Notes

Reaction equation

HRID 1030828 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 9211Benzopyran

Reagents, catalysts & solvents 1

HCID 24462Copper SulfateCatalyst

Procedure

In 50 cc of anhydrous ether was dissolved 3.06 g (0.01 mole) of the chromanone compound obtained in Example 32, represented by the following formula: ##STR163## and the solution was cooled to 0° C. and Grignard reagent CH3MgI (0.012 mole) newly prepared in 50 cc of anhydrous ether was dropped into the solution over a period of about 1 hour. After termination of the dropwise addition, the mixture was stirred at room temperature for 2 hours and quietly poured into cold water to extract the product with ether. The ether extract was dried on magnesium sulfate to form a chromanol compound from the chromanone compound. Then, the chromanol compound was heated at 200° C. together with anhydrous copper sulfate in a carbon dioxide current for about 10 minutes. The obtained brown viscous liquid was purified by the chromatography on silica gel to obtain 2.47 g of a chromene compound represented by the following formula: ##STR164##

Workup

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

Sources & evidence

ORD record
ord-e0357ae58afd42058bfa5cfb54e114da
Source dataset
uspto-grants-1992_04
Patent number
US05106998

Reaction notes

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