Ethyl 4-iodobenzoate → Ethyl 4-[(2,2,4,4,7-pentamethylchroman-6-yl)-ethynyl]benzoate

Participants

Reaction Conditions

Reaction Steps

Nitrogen was bubbled for 15 min through a solution of 200 (0.877 mmol) of 2,2,4,4,7-pentamethyl-6-ethynylchroman (Compound 9) and 245.3 mg (0.888 mmol) of ethyl 4-iodobenzonate (Compound 97) in 2 ml of triethylamine. The mixture was then placed under an argon atmosphere and treated with a finely ground mixture of 50 mg (0.2625 mmol) of cuprous iodide and 100 mg (0.1425 mmol) of bis(triphenylphosphine) palladium (II) chloride. The reaction vessel was then fitted with a reflux condenser and the mixture was heated at 55 degrees C. under argon for 72 hours. The triethylamine was then removed under vacuum and the residue purified by flash chromatography (silica, 5% ethyl acetate in hexane) to give the title compound as a yellow oil. PMR (CDCl3) : & 1.32 (12H, s), 1.37 (3H, t, J~7.0 Hz), 1.80 (2H, s) 2.40 (3H, s), 4.36 (2H, q, J~7.0 Hz), 6.66 (1H, s, 7.42 (1H, s), 7.54 (2H, d, J~8.6 Hz), 7.99 (2H, d, J~8.6 Hz). MS exact mass, m/e 376.2 038 (calcd. for C25H28O3, 376 2038).

Provenance & Evidence