[Li].[CH2:2](Cl)[C:3]([CH3:6])([CH3:5])[CH3:4].[F:8][C:9]1[CH:14]=[CH:13][CH:12]=[C:11](F)[C:10]=1[C:16]1[O:17][CH2:18][C:19](C)(C)[N:20]=1.C([O-])(O)=O.[Na+]>C1COCC1>[CH3:4][C:3]([CH3:6])([CH3:5])[CH2:2][C:11]1[CH:12]=[CH:13][CH:14]=[C:9]([F:8])[C:10]=1[C:16]([NH:20][CH2:19][CH3:18])=[O:17]
A solution of p,p'-di-t-butyl biphenyl (5.559 g, 0.021 mol) and THF (100 mL) was stirred at 0° C. under an atmosphere of argon. Lithium wire (0.021 mol, 0.15 g) was added in small pieces and the mixture was allowed to stir at 0° C. for 24 h. The mixture was cooled to -78° C. and neopentyl chloride (2.0 g, 0.01875 mol) was added dropwise. The mixture was stirred at -78° C. for 1 h, and the compound of Example g (3.17 g, 0.015 mol) was added all at once. The mixture was continuously stirred or 4 h and 50 mL sat aq NaHCO3 was added. This mixture as extracted with three 50 mL portions of ethyl acetate. The combined extracts were washed twice with water, dried (MgSO4), and concentrated. The crude concentrate was purified by HPLC eluting with 1:4 ethyl acetate/hexanes. The oxazoline was as a clear oil in 27% yield.
Loading…
