2-Methylfuran → N-[5-(2-methyl-5-furyl)thiophene-2-sulfonyl]pyrrole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

t-BuLi (1.7 m solution in hexane, 7.9 ml, 14.6 mmol) was added dropwise under constant stirring under a nitrogen atmosphere to a solution of 2-methylfuran (1.0 g, 12 mmol) in THF (20 ml) at −78° C. The solution was then warmed to −10° C. and stirring continued for 45 min. The solution was then added to a solution of zinc chloride (27 ml of a 0.5 M solution in THF) at −30° C. and then warmed to room temperature where stirring continued for 1 hr. resulting in a pale yellow clear solution. The solution was then transferred via a steel canula under nitrogen to a solution of N-(5-bromothiophene-2-sulfonyl)pyrrole (Example 33A, 3.5 g, 12 mmol) and tetrakis(triphenylphosphine)-palladium (0) (693 mg, 0.6 mmol) in THF (15 ml) at −78° C. The solution was then warmed to room temperature and stirred for a period of 2 hours. Purification by column chromatography using 2% ethyl acetate gave 680 mg of N-[5-(2-methyl-5-furyl)thiophene-2-sulfonyl]pyrrole as a pale yellow powder (19% yield).

Herkunft & Nachweise