2-Hydrazinoethanol → methyl 1-(2-hydroxyethyl)-1H-indazole-7-carboxylate

HRID 2168556Notes

Reaction equation

HRID 2168556 reaction equation
F[C:2]1[C:11]([CH:12]=O)=[CH:10][CH:9]=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].[OH:14][CH2:15][CH2:16][NH:17][NH2:18]>CO>[OH:14][CH2:15][CH2:16][N:17]1[C:2]2[C:11](=[CH:10][CH:9]=[CH:8][C:3]=2[C:4]([O:6][CH3:7])=[O:5])[CH:12]=[N:18]1

Participants

4

Reactant 2

HCID 80172-HydrazinoethanolHCID 57423810Methyl 2-fluoro-3-formylbenzoate

Product 1

HCID 66899478methyl 1-(2-hydroxyethyl)-1H-indazole-7-carboxylateYield 65%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of methyl 2-fluoro-3-formylbenzoate (3.6 g, 19.9 mmol) from Step C above and hydroxy ethyl hydrazine (1.5 g, 19.9 mmol) in MeOH (16 mL) was irradiated with microwaves at 150° C. for 1.5 h. The reaction mixture was cooled and partitioned between H2O and ethyl acetate. The aqueous phase was extracted with additional ethyl acetate and then the combined organic extracts were dried (Na2SO4) filtered, concentrated and purified by column chromatography (silica gel, 70:30 hexanes/ethyl acetate) to afford methyl 1-(2-hydroxyethyl)-1H-indazole-7-carboxylate as a yellow solid (2.83 g, 65%): 1H NMR (500 MHz, CDCl3) δ 8.13 (s, 1H), 7.99 (d, J=7.5 Hz, 1H), 7.94 (d, J=8.0 Hz, 1H), 7.18 (t, J=8.5 Hz, 1H), 4.84 (t, J=5.0 Hz, 2H), 4.13-4.07 (m, 2H), 3.99 (s, 3H), 3.20-3.10 (m, 1H).

Workup

  1. customwas irradiated with microwaves at 150° C. for 1.5 h
  2. temperatureThe reaction mixture was cooled
  3. custompartitioned between H2O and ethyl acetate
  4. extractionThe aqueous phase was extracted with additional ethyl acetate
  5. dry with materialthe combined organic extracts were dried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated
  8. custompurified by column chromatography (silica gel, 70:30 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-50ffc04a1e5c49899b5986eb4f65eded
Source dataset
uspto-grants-2015_06
Patent number
US09045501B2

Reaction notes

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