2-Acetylfuran → Lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate

Temperature

-78 °C

A 1-L flame-dried flask was charged with 130 mL of LiHMDS (130 mmol; 1.0 M in THF) and 410 mL of ethyl ether. The resulting solution was cooled to −78° C. and 2-acetylfuran (14 g, 12 m mmol) was added in one portion. After 5 min, di-tert-butyl oxalate was added dropwise over 1 h as a solution in 100 mL of ether. The resulting mixture was warmed to 23° C. over a period of 3 h and was maintained at room temperature for 20 h. The mixture was then filtered, and the resulting beige precipitate was washed with 100 mL of ether. The filter cake was dried in a vacuum oven for 1 h to afford lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate (25 g, 83%) as a cream colored solid. 1HNMR (DMSO-d6) δ 7.75 (t, 1H), 6.96 (m, 1H), 6.56 (m, 1H), 3.34 (s, 2H), 1.46 (s, 9H).

1. dry with materialA 1-L flame-dried flask
2. temperatureThe resulting mixture was warmed to 23° C. over a period of 3 h
3. temperaturewas maintained at room temperature for 20 h
4. filtrationThe mixture was then filtered
5. washthe resulting beige precipitate was washed with 100 mL of ether
6. customThe filter cake was dried in a vacuum oven for 1 h

ORD record

ord-a9fc6d12acce4f4e93c90754ef5b15fa

Source dataset

uspto-grants-2005_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06949550B2