Sodium Carbonate → methyl 7-ethyl-3-methyl-1H-indazole-5-carboxylic acid

HRID 1880409Notes

Reaction equation

[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][C:7]([C:13]([OH:15])=[O:14])=[CH:8][C:9]=2[CH2:11][CH3:12])[C:4](I)=[N:3]1.[C:17]([O-])([O-])=O.[Na+].[Na+]>COCCOC>[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][C:7]([C:13]([OH:15])=[O:14])=[CH:8][C:9]=2[CH2:11][CH3:12])[C:4]([CH3:17])=[N:3]1

Participants

Conditions

Temperature: 125 °C

Procedure

To a degassed solution of methyl 7-ethyl-3-iodo-1H-indazole-5-carboxylic acid (100 mg, 0.30 mmol) in DME (2.5 mL) was added degassed boroxine solution (50%, 0.28 mL) followed by palladium tetrakistriphenylphosphine (3.5 mg, 0.003 mmol) and 2 M Na2CO3 (0.57 mL). The mixture was heated in a microwave reactor (very high absorption setting) at 125° C. for 10 minutes and then at 165° C. for 10 minutes. The reaction was extracted with EtOAc and washed with saturated aqueous NaCl. The organic extract was reduced and the crude material was purified by silica gel chromatography (40 g column) using 0-40% EtOAc/heptane to afford methyl 7-ethyl-3-methyl-1H-indazole-5-carboxylic acid (18 mg, 27%).

Workup

customdegassed boroxine solution (50%, 0.28 mL)
extractionThe reaction was extracted with EtOAc
washwashed with saturated aqueous NaCl
extractionThe organic extract
customthe crude material was purified by silica gel chromatography (40 g column)

Sources & evidence

ORD record: ord-096c397ff8024a718a673e27f4f1414e
Source dataset: uspto-grants-2012_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08318762B2

Reaction notes

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