反应详情

温度

100 °C

tert-Butyl 4-iodobenzoate (25.9 g, 85.2 mmol) and 2,2,6,6-tetramethyl-3,5-heptanedione (7.01 mL, 34.1 mmol) were diluted with NMP (70 mL) and bubbled with Argon for 20 minutes. Copper (I) chloride (16.9 g, 170 mmol), ethyl 6-chloro-7-hydroxychroman-4-carboxylate (24.0 g, 93.7 mmol) and cesium carbonate (55.5 g, 170 mmol) were combined and added to the reaction using a small funnel which was rinsed with NMP (30 mL). The reaction was purged for an additional 10 minutes and then heated to 100° C. and stirred for 5 hours under Argon. The reaction was cooled and loaded directly onto a silica plug (2 kg) and eluted with 10% ethyl acetate/hexanes to yield 10 g of crude product. The crude material was purified by silica gel column chromatography, eluting with 5% ethyl acetate/hexanes to 50% ethyl acetate/hexanes to provide the desired product (14 g, 32.3 mmol, 38.0% yield) as a viscous oil.

1. custombubbled with Argon for 20 minutes
2. additionadded to the reaction
3. washwas rinsed with NMP (30 mL)
4. customThe reaction was purged for an additional 10 minutes
5. temperatureThe reaction was cooled
6. washeluted with 10% ethyl acetate/hexanes
7. customto yield 10 g of crude product
8. customThe crude material was purified by silica gel column chromatography
9. washeluting with 5% ethyl acetate/hexanes to 50% ethyl acetate/hexanes