Sodium Chloride → methyl 1-benzyl-1H-indazole-3-carboxylate

HRID 1743362Notes

Reaction equation

[H-].[Na+].[CH3:3][O:4][C:5]([C:7]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[NH:9][N:8]=1)=[O:6].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.[Na+].[Cl-]>C1COCC1>[CH3:3][O:4][C:5]([C:7]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[N:9]([CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[N:8]=1)=[O:6]

Participants

Conditions

Temperature: 25 °C

Procedure

Sodium hydride (0.37 g, 60%, 9.3 mmol) was added to a solution of indazole-3-carboxylic acid methyl ester (1.5 g, 8.5 mmol) in dry THF (50 mL) at 0° C. Benzyl bromide (1.59 g, 9.3 mmol) was then added and the reaction mixture was warmed to 25° C. and stirred for 8 h. The reaction mixture was poured onto saturated NaCl solution (100 mL) and extracted with 3×200 mL of diethyl ether. The combined extracts were dried (MgSO4) and concentrated under reduced pressure. The crude compound was purified by flash chromatography using cyclohexane/ethyl acetate (70:30) and recrystallised from cyclohexane/ethyl acetate to afford the title compound as a yellow solid (1.89 g,84%). Mp 72–73° C. 1H NMR (300 MHz, CDCl3) ppm 4.07 (s, 3H), 5.72 (s, 2H), 7.22–7.40 (m, 8H), 8.24–8.27 (m, 1H). MS(EI) m/z 266 [M+]. Anal. Calcd. for C16H14N2O2: C, 72.17; H, 5.30; N, 10.52. Found: C, 72.12; H, 5.15; N, 10.85.

Workup

extractionextracted with 3×200 mL of diethyl ether
dry with materialThe combined extracts were dried (MgSO4)
concentrationconcentrated under reduced pressure
customThe crude compound was purified by flash chromatography
customrecrystallised from cyclohexane/ethyl acetate

Sources & evidence

ORD record: ord-500e0b79f1aa4e1489938c4e1a490d18
Source dataset: uspto-grants-2006_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07009056B2

Reaction notes

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