3-Methyl-2-butanone → 5-Methoxy-2,3,3-trimethyl-3H-indole

Participants

Reaction Conditions

Reaction Steps

A mixture of (4-methoxyphenyl)hydrazine (0.98 g, 7.1 mmol) and 3-methylbutan-2-one (1.53 g, 17.8 mmol) in 20 mL of HOAc was heated at 100° C. overnight. The mixture was concentrated and 1N NaOH was added until pH 9 to 10. The aqueous solution was extracted with ethyl acetate (50 mL×3). The combined organic layers were dried over Na2SO4. After filtration and concentration, the residue was purified by flash column chromatography to give 610 mg of 5-methoxy-2,3,3-trimethyl-3H-indole (45%). 1H NMR (CDCl3) δppm: 7.43 (dd, 1H), 6.81 (m, 2H), 3.83 (s, 3H), 2.26 (s, 3H), 1.28 (s, 6H). LC-MS (M+H): 190.16

Provenance & Evidence