Acetic Acid → 5,7-Dimethyl-1H-indazole

Participants

Reaction Steps

N-(2,4,6-trimethyl-phenyl)-acetamide (23.8 g, 133 mmol) (prepared as described in Example 12) was dissolved in a mixture of toluene (300 mL) and glacial AcOH (10.4 g, 173 mmol, 1.3 eq) and then treated slowly with isoamyl nitrite (20.3 g, 23.2 mL, 173 mmol, 1.3 eq). The mixture was heated at reflux overnight or until all the starting material was consumed as judged by TLC (30% EtOAc-hexanes). The solution was then poured into H2O (1.3 L) and extracted with EtOAc (2×300 mL). The combined organic extracts were then washed with saturated aq. NaHCO3 solution (2×200 mL) and brine (1×100 mL). The extracts were dried (MgSO4), filtered, and concentrated to provide 19.5 g of 5,7-dimethyl-1H-indazole 2 as a red waxy solid. This material was carried on without additional purification. RP-HPLC Method: 2-100% B in 2 minutes

Provenance & Evidence