1-Tridecyne → Methyl 3-[2-(1-tridecynyl)phenyl]-2-E-(diethoxyphosphinyl)-2-propenoate

Participants

Reaction Steps

Methyl 3-(2-bromophenyl)-2-E-(diethoxyphosphinyl)-2-propenoate (11.31 g, 29.99 mmol) prepared according to Example 16 was mixed with 1-tridecyne (9.50 g, 52.68 mmol) and triphenylphosphine (0.214 g, 0.82 mmol) in a 500 ml four-neck round bottom flask equipped with a magnetic stir bar, condenser topped with an argon inlet, and an internal thermometer. Dry triethylamine (156 ml) was added, and the flask was closed. The system was inerted and a bubbler was connected to the argon line. Palladium acetate (0.0733 g, 0.33 mmol) was added, and the reaction mixture was heated in an oil bath (T=100° to 105° C.). The reaction was refluxed for 50 hours. At the end of this time, the reaction mixture was cooled to room temperature and was filtered. The white precipitate was washed with triethyl amine (100 ml). The filtrates were stripped down to a dark oil. This oil was extracted three times with acetonitrile (50 ml). The combined acetonitrile extracts were stripped down to an orange oil which was chromatographed on silica eluting with petroleum ether-dichloromethane (68:32) increasing to pure dichloromethane, then with hexanesethyl acetate (1:1) increasing to pure ethyl acetate. Fractions containing a spot with Rf =0.20 on silica developed with hexane-dichloromethane (68:32) were combined and stripped. Reverse phase chromatography on C18 silica, eluting with 10% water in methanol, was done. Fractions were combined which showed the above Rf. These fractions were rechromatographed on silica eluting with hexanes-ethyl acetate (66:34) and progressing to hexanes-ethyl acetate (60:40). Additional rechromatography of impure fractions gave 4.18 g (8.77 mmol, 29% yield) of pure product as a pale yellow oil. 1H NMR (CDCl3) ∂ 0.88 (t, J=6.7 Hz, 3H), 1.17 to 1.50 (several m, 22H), 1.63 quintet, J=7.6 Hz, 2H), 2.43 (t, J=7.2 Hz, 2H), 3.72 (s, 3H), 4.21 (m, 4H), 7.19 to 7.36 (several m, 3H), 7.44 (dm, J=7.6 Hz, 1H), 8.05 (d, J=23.8 Hz); EI mass spectrum m/z 476 (M+).

Provenance & Evidence