Sodium hydride → methyl 6-bromo-1-cyclobutyl-1H-indole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

In an oven dried 100 ml RBF, equipped with a stir bar, septum, nitrogen inlet was added methyl 6-bromo-1H-indole-4-carboxylate (1.0 g, 3.94 mmol) and (cyanomethyl)(trimethyl)phosphonium chloride (1.491 g, 9.84 mmol). Added in THF (40 mL) and stirred suspension for 5 min. The reaction was cooled with an ice bath for 10 min, then was added cyclobutanol (0.616 mL, 7.87 mmol), followed by sodium hydride (0.346 g, 8.66 mmol) portionwise. The ice bath was removed and the reaction stirred at ambient temperature for 45 min, then heated at 50° C. for 18 h. LCMS showed mostly SM. Heated at 75° C. for 24 h. The reaction was allowed to cool to RT, then poured into water (200 ml) and extracted with EtOAc (2x). The combined organics were dried over magnesium sulfate, filtered, and concnentrated. Purification of the residue by column chromatography (40 g Isco silica column; gradient B: 2-25%; A: hexane, B: EtOAc) gave methyl 6-bromo-1-cyclobutyl-1H-indole-4-carboxylate (0.3 g, 25% yield, ˜45% pure by HPLC). MS(ES) [M+H]+ 308.2.

Provenance & Evidence