Tributylvinyltin → Ethyl 2-vinylthiazole-5-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of tributyl(vinyl)stannane (0.92 mL, 3.14 mmol) and ethyl 2-bromothiazole-5-carboxylate (0.38 mL, 2.54 mmol) in dioxane (33 mL) is added Pd(PPh3)2Cl2 (182 mg, 0.26 mmol) at room temperature. After stirring at 100° C. under nitrogen for 4 hours, the solution is cooled to ambient temperature and then quenched with H2O. The crude is diluted with EtOAc, the organic layer is washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The obtained residue is purified by flash column chromatography on silica gel (eluent: heptane/EtOAc=90:10 to 80:20) to give ethyl 2-vinylthiazole-5-carboxylate (418 mg). HPLC retention time=0.45 minutes (condition B); MS (m+1)=184.1; 1H NMR (400 MHz, CD3OD) δ ppm 1.37 (t, J=7.2 Hz, 3 H) 4.35 (q, J=7.1 Hz, 2 H) 5.71 (d, J=10.9 Hz, 1 H) 6.24 (d, J=17.4 Hz, 1 H) 6.93 (dd, J=17.4, 10.9 Hz, 1 H) 8.29 (s, 1 H)

Herkunft & Nachweise