Lithium Hexamethyldisilazide → 1-Bromo-5-(4-Cyanophenyl]-4-Pentene

Temperatur

-20 °C

Add (4-cyanophenylmethyl)triphenylphosphonium bromide (27.25 g) to dry THF (65 ml) and cool to -20° C. under an argon atmosphere. With stirring, dropwise add 65 ml of a solution of 1 molar lithium bis(trimethylsilyl)amide in THF, maintaining the temperature at -20° C. Stir for 30 minutes at -20° C.; then for 30 minutes at 0° C. Cool to -20° C. and add freshly distilled 4-bromobutanal (10.50 g) dropwise with stirring. Stir at -20° C. for 1 hour, then at room temperature for 16 hours. Remove the solid material by filtration and wash with THF. Vacuum evaporate the solvent from the filtrate and purify the resultant residue by chromatography on silica gel, eluting with CH2Cl2 :hexane(4:1). Combine the desired fractions and vacuum evaporate the solvent to obtain the title compound.

1. stirringStir for 30 minutes at -20° C.
2. temperatureCool to -20° C.
3. stirringwith stirring
4. stirringStir at -20° C. for 1 hour
5. waitat room temperature for 16 hours
6. customRemove the solid material
7. filtrationby filtration
8. washwash with THF
9. customVacuum evaporate the solvent from the filtrate
10. custompurify the resultant residue by chromatography on silica gel
11. washeluting with CH2Cl2 :hexane(4:1)
12. customCombine the desired fractions and vacuum evaporate the solvent

ORD-Eintrag

ord-95ec76cba9974f7089f7625cf3e0cc85

Quelldatensatz

uspto-grants-1987_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04634689