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 rt for 20 h. The mixture was then filtered, and the resulting beige precipitate was washed with 100 mL of ether. The filter cake was then 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. 1H NMR (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 rt 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 then dried in a vacuum oven for 1 h

ORD record

ord-b14efd3505b54a07bbd2d0576b9e12ca

Source dataset

uspto-grants-2005_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06967208B2