Cesium carbonate → Ethyl 3-(4-chlorophenyl)propiolate

Temperature

35 °C

A mixture of 1-chloro-4-iodobenzene (120.4 g, 0.50 mol) and cesium carbonate (352.8 g, 1.0 mol) in tetrahydrofuran (1.275 L) was evaporated and flushed with argon. Then cuprous iodide (3.81 g, 20.0 mmol) and bis(triphenylphosphine)palladium(II) chloride (7.02 g, 10.0 mmol) were added and then ethyl propiolate (100 g, 1.01 mol) was added dropwise over a period of 20 min. The resulting dark brown suspension was stirred for 41 h at 35° C., then filtrated over Hyflo® and washed with THF (5 L). The solution was concentrated and treated with toluene/heptane 1:2 (1.5 L) and stirred for 1 h at 45° C. under reduced pressure (250 mbar). The resulting suspension was filtered and the residue was washed with further toluene/heptane 1:2 (1.5 L). The solid was dried affording 181.64 g (MS m/e: 209.0/211.2 [M+H]+) of a dark brown oil as crude product which was used without further purification.

1. customwas evaporated
2. customflushed with argon
3. filtrationfiltrated over Hyflo®
4. washwashed with THF (5 L)
5. concentrationThe solution was concentrated
6. additiontreated with toluene/heptane 1:2 (1.5 L)
7. stirringstirred for 1 h at 45° C. under reduced pressure (250 mbar)
8. filtrationThe resulting suspension was filtered
9. washthe residue was washed with further toluene/heptane 1:2 (1.5 L)
10. customThe solid was dried
11. customaffording 181.64 g (MS m/e: 209.0/211.2 [M+H]+) of a dark brown oil as crude product which
12. customwas used without further purification

ORD record

ord-a75741212b6a46e3a4540f3d75a5e654

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09226916B2