Water → Ethyl E-2-phosphono-3-[2-(1-tridecynyl)phenyl]propenoate

Participants

Reaction Conditions

Reaction Steps

Ethyl 2-(diethoxyphosphinyl)-3-[2-(1-tridecynyl)phenyl]-2-E-propenoate (0.50 g, 1.02 mmol) prepared according to Example 5 was dissolved in dry CH2Cl2 (3 ml) and CD2Cl2 (2 ml, dried over activated neutral alumina) and cooled to 0° C. Bromotrimethylsilane (0.31 ml, 2.35 mmol) was added over a two to three minute period. The progress of the reaction was monitored by 31P NMR, to follow disappearance of the starting material. After about 5 hours, the solvent was removed under reduced pressure. Acetone-heptane (5.5 ml, 10:1) containing 0.045 ml (2.5 mmol) water was added and the reaction was stirred for 1.5 hours. At the end of this time the solvent was stripped. Since NMR indicated incomplete reaction, acetone (5 ml) containing water (0.05 ml, 2.8 mmol) was added and stirring was continued for two hours. After stripping the solvent, the reaction was still incomplete. It required 2.5 more hours under these conditions to complete the reaction. The solvent was stripped off and the residue was chromatographed on silica eluting with 10% chloroform and 20% methanol in heptane. Fractions containing product were recrystallized from heptane yielding a white solid, 0.211 g, 0.486 mmol, 47.6% yield; mp 68°-69° C.; 1H NMR (CDCl3) ∂ 0.86 (m, 3H), 1.09 to 1.63 (several m, 21H), 2.40 (t, J=7.1 Hz, 2H), 4.19 (q, J=7.1 Hz, 2H), 7.17 to 7.44 (several m, 4H), 8.15 (d, J=24.7 Hz, 1H), 8.81 (br s, 2.7H); FAB mass spectrum m/z 434 (M+H)+.

Provenance & Evidence