Ethyl trifluoroacetate → 1-Tetralone

HRID 2227399Notes

Reaction equation

HRID 2227399 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

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 stem 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 substituted hydrazine at reflux for 24 hours to afford a mixture of pyrazoles (11) and (12). Recrystallization gives the 4,5-dihydrobenz[g]indazolyl-benzenesulfonamide (11).

Sources & evidence

ORD record
ord-1fc64fdc11a84faf9cd52064646a2ed8
Source dataset
uspto-grants-2002_07
Patent number
US06413960B1

Reaction notes

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