Toluene → methyl 2-(2-bromo-E-ethenyl)-delta-oxobenzenepentanoate

Temperature

120 °C

To 10 ml of toluene was added 6.0g (9.9 mmol) of trans-1,2-bis(tri-n-butylstannyl)ethylene, which was prepared according to the procedure of Corey, et al., J. Org. Chem., 40, 3788 (1975), and 0.5 g (1.8 mmol) of the product of Example 3. To the solution was then added 0.040 g (0.035 mmol) of 2 mole% tetrakis(triphenylphosphine)palladium(0) and the solution was degassed with argon. The reaction mixture was heated under argon for 1 hour at 120 ° C. (oil bath). Thereafter, the reaction mixture was cooled to -20° C. To the reaction mixture was added dropwise with stirring, a solution of 1.5 ml (29.1 mmol) of Br2 in 30 ml of CCl4 until thin layer chromatography of the reaction mixture indicated that all of the product of Example 3 was consumed. The volatile components were removed in vacuo. The residue was flash chromatographed on a silica gel column. Sequential elution with hexane, 5% diethyl ether in hexane, and 10% diethyl ether in hexane produced 0.48 g of the titled product. The product was triturated with cold hexane to give a white solid, m.p. 52°-55° C.

1. customwas prepared
2. customthe solution was degassed with argon
3. temperatureThereafter, the reaction mixture was cooled to -20° C
4. additionTo the reaction mixture was added dropwise
5. customwas consumed
6. customThe volatile components were removed in vacuo
7. customchromatographed on a silica gel column
8. washSequential elution with hexane, 5% diethyl ether in hexane, and 10% diethyl ether in hexane

ORD record

ord-7fa6f60eb32f42aebb4854c5cd83410d

Source dataset

uspto-grants-1990_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04970229