1H-Indazole → 1-Tetralone

HRID 1720104Notes

Reaction equation

HRID 1720104 reaction equation
N1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=N1.FC(F)(F)C([O:14][CH2:15][CH3:16])=O.[CH3:19][O-].[Na+]>CO>[C:15]1(=[O:14])[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][CH2:19][CH2:16]1

Participants

5

Reactant 3

HCID 92211H-IndazoleHCID 9794Ethyl trifluoroacetateHCID 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##

Workup

  1. customfor preparation of 4,5-dihydrobenz g

Sources & evidence

ORD record
ord-1e0f7ef93445453db45b3485f7b5b2d3
Source dataset
uspto-grants-1996_04
Patent number
US05504215

Reaction notes

Loading…