Triphenylphosphine → 4-(2-Ethoxy-vinyl)-2-methylsulfanyl-pyrimidine

Temperature

0 °C

Ethyl ethynyl ether (2.50 g, 35.7 mmol) was dissolved in 50 mL anhydrous THF under N2. The solution was cooled to 0° C. and BH3-THF (1.0 M in THF, 11.9 mL, 11.9 mmol) was added drop-wise. The reaction was allowed to warm to RT and after 2 h the tris-(2-ethoxy-vinyl)borane that was generated was used in the next step. A flame dried flask under N2 was charged with 4-chloro-2-(methylthio)pyrimidine (0.200 g, 1.25 mmol), Pd(OAc)2 (0.003 g, 0.01 mmol), PPh3 (0.010 g, 0.040 mmol), NaOH (0.149 g, 3.73 mmol). Anhydrous THF, 2 mL, was added followed by the addition of 0.700 mL (0.50 mmol) of the solution of tris-(2-ethoxy-vinyl)borane generated above. The reaction was heated at reflux for 16 h, then was cooled to RT and quenched with sat NaHCO3 (aq). The mixture was extracted 3× with EtOAc and the combined organic extracts were dried over Na2SO4, filtered and concentrated. The product was purified to moderate purity by flash column chromatography and used in the next step.

1. customA flame dried flask under N2
2. temperatureThe reaction was heated
3. temperatureat reflux for 16 h
4. temperaturewas cooled to RT
5. customquenched with sat NaHCO3 (aq)
6. extractionThe mixture was extracted 3× with EtOAc
7. dry with materialthe combined organic extracts were dried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe product was purified to moderate purity by flash column chromatography

ORD record

ord-5ddcead28a714814bbf1a5f089217c83

Source dataset

uspto-grants-2003_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06586423B2