Ethylene Glycol → 5-(1,3-Dioxolan-2-yl)-3-iodo-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-indazole

Participants

Reaction Steps

6.11 g (15.2 mmol) 3-iodo-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-indazole-5-carbaldehyde (Example 4A), 2.82 g (45.6 mmol) ethylene glycol and a trace amount of p-toluenesulfonic acid in toluene (100 ml) were heated to reflux overnight using a Dean-Stark trap. After cooling, the mixture was extracted twice with saturated aqueous sodium bicarbonate solution and washed with brine. The organic layer was dried with sodium sulfate, filtered and evaporated to dryness. The remaining substance was purified by preparative RP-HPLC (acetonitrile/water gradient) yielding 3.94 g (58% of th.) of the pure title compound.

Provenance & Evidence