Tributylstannane → 4-Chloro-2-(tributylstannyl)pyrimidine

Temperatur

-20 °C

To a solution of LDA (251 ml, 502 mmol) in THF (650 mL) at −20° C. was added SnBu3H (108.5 ml, 402 mmol) dropwise. The mixture was maintained at −20° C. for 15 min, then cooled to −78° C. 2,4-dichloro pyrimidine (50 g, 335 mmol) was added and the reaction was stirred at −78° C. for 5 h. The cooling bath was removed and the reaction was slowly warmed to 0° C. within 30 min. The mixture was poured into 10% NH4Cl at 0° C., and the aqueous layer was extracted with Et2O. The combined organic layers were washed with brine, dried, filtered and concentrated. The residue was purified with silica gel chromatography (eluting with 1% EtOAc in Hex) to give 4-chloro-2-(tributylstannyl)pyrimidine (18.5 g, 24%) as a pale yellow color syrup. MS (ESI, pos. ion) m/z: 405.1 (M+1); 1H-NMR (400 MHz, CDCl3): δ 8.54 (d, J=8 Hz, 1H), 7.17 (d, J=8 Hz, 1H), 1.61-1.54 (m, 6H), 1.37-1.28 (m, 6H), 1.21-1.17 (m, 6H), 0.90 (m, 9H).

1. temperaturecooled to −78° C
2. customThe cooling bath was removed
3. temperaturethe reaction was slowly warmed to 0° C. within 30 min
4. additionThe mixture was poured into 10% NH4Cl at 0° C.
5. extractionthe aqueous layer was extracted with Et2O
6. washThe combined organic layers were washed with brine
7. customdried
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified with silica gel chromatography (eluting with 1% EtOAc in Hex)

ORD-Eintrag

ord-5ddfb110bfdb4f97adfc2b9b2924af16

Quelldatensatz

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09321756B2