Ethyl trifluoroacetate → 1-Tetralone

HRID 864534Notes

Reaction equation

HRID 864534 reaction equation
N1[C:9]2[C:8]3[CH:10]=[CH:11][CH:12]=[CH:13][C:7]=3[CH2:6][CH2:5][C:4]=2C=N1.FC(F)(F)C(OCC)=[O:17].C[O-].[Na+]>CO>[C:9]1(=[O:17])[C:8]2[C:7](=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH2:6][CH2:5][CH2:4]1

Participants

5

Reactant 3

HCID 9794Ethyl trifluoroacetateHCID 3398588HCID 3398588, compoundHCID 10942334Sodium Methoxide

Product 1

HCID 107241-Tetralone

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Synthetic Scheme III shows the procedure for preparation of 4,5-dihydrobenz[g]indazole compounds embraced by Formula I. In step 1, ethyl trifluoroacetate is reacted with base, such as 25% sodium methoxide in a protic solvent, such as methanol, and a 1-tetralone derivative (9) to give the intermediate diketone (10). In step 2, the diketone (10) in an anhydrous protic solvent, such as absolute ethanol or acetic acid, is treated with the free base or hydrochloride salt of a phenylhydrazine at reflux for 24 hours to afford a mixture of pyrazoles (11) and (12). Recrystallization gives the 4,5-dihydro benz[g]indazolyl-benzenesulfonamide (11). ##STR12##

Sources & evidence

ORD record
ord-cb54288ffe9941a9b41b63116aed65f2
Source dataset
uspto-grants-1996_10
Patent number
US05563165

Reaction notes

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