Trifluoroacetic acid → 6-bromo-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

HRID 1453636Notes

Reaction equation

HRID 1453636 reaction equation
[C:1]([C:4]1[CH:9]=[C:8]([Br:10])[CH:7]=[CH:6][C:5]=1[OH:11])(=[O:3])[CH3:2].N1CC[CH2:15][CH2:14][CH2:13]1.FC(F)(F)C(O)=O>CC(C)=O>[Br:10][C:8]1[CH:9]=[C:4]2[C:5](=[CH:6][CH:7]=1)[O:11][C:14]([CH3:15])([CH3:13])[CH2:2][C:1]2=[O:3]

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 8082PiperidineHCID 959915'-Bromo-2'-hydroxyacetophenone

Product 1

HCID 147553646-bromo-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

In another exemplary reaction sequence shown in Reaction Scheme 15, 4-bromophenol is reacted with acetyl chloride (AcCl) to provide the corresponding ester, and the ester made to undergo a Fries rearrangement under Friedel Crafts conditions to provide 2-acetyl-4-bromophenol. 2-Acetyl-4-bromophenol is reacted with acetone in the presence of piperidine and trifluoroacetic acid (TFA) to give 6-bromo-2,2-dimethyl-chroman-4-one. The latter compound is reacted with the Grignard reagent of the formula R1MgX and then with acid to provide the 6-bromo-2,2-dimethyl-chromene derivative of Formula 17.

Sources & evidence

ORD record
ord-497c2558ff0d4d21b59cdeffcd31710d
Source dataset
uspto-grants-2009_01
Patent number
US07476673B2

Reaction notes

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