Acetic Acid → 1H-Indazole

HRID 2181559Notes

Reaction equation

HRID 2181559 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3](C=O)=[N:2]1.NN1C=CC=C1.C(O)(=O)C>C(O)C>[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[N:2]1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 1365891-AminopyrroleHCID 178520025HCID 178520025, compound

Product 1

HCID 92211H-IndazoleYield 200.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 6-pyridin-4-yl-1-(2-trimethylsilanyl)-ethoxymethyl)-1H-indazole-3-carbaldehyde (208 mg, 0.59 mmol), N-aminopyrrole (145 mg, 1.76 mmol), and acetic acid (5.8 μl) in ethanol (1 ml) was held at 95° C. for 16 h. The solution was then evaporated under reduced pressure, and purified by silica gel chromatography to give 1H-indazole as an oil (140 mg, 57%). 1H NMR (300 MHz, CDCl3) 9.08 (s, 1H), 8.71 (d, 2H, J=6.1 Hz), 8.46 (d, 1H, J=85 Hz), 834 (s, 1H), 7.85 (d, 2H, J=6.2 Hz), 7.80 (d, 1H, J=8.5 Hz), 7.56 (t, 2H, J=23 Hz), 6.25 (t, 2H, J=2.3 Hz), 5.93 (s, 1H), 5.74 (s, 2H), 3.64 (t, 2H, J=7.9 Hz), 0.86 (t, 2H, J=7.9 Hz), 0.00 (s, 9H).

Workup

  1. customThe solution was then evaporated under reduced pressure
  2. custompurified by silica gel chromatography

Sources & evidence

ORD record
ord-724e9fe38a1b4c33ab564da5f6a31de4
Source dataset
uspto-grants-2005_05
Patent number
US06891044B2

Reaction notes

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