反应详情

The benzophenone imine of glycine t-butyl ester 3 (1.8 mmol), tetra-n-butyl-ammonium bromide (0.2 mmol), dichloromethane (6 mL), and 4-chlorobenzyl bromide 136 (2 mmol) were added to a three-necked round-bottom flask equipped with a stirring bar. 50% aqueous NaOH (36.5 mmol) was added at once and the resulting mixture was stirred vigorously at room temperature until starting Schiff base had disappeared by TLC (4:1 hexane/EtOAc) (approximately 8 h). Water (3 mL) and dichloromethane (3 mL) were added and the mixture was transferred to a separatory funnel. The organic layer was separated and evaporated in vacuo. The residue was taken up in ether (10 mL) and water (6 mL), and the ether layer was separated and washed with water (3×3.0 mL). The organic layer was dried (Na2SO4), filtered, and evaporated in vacuo. The resulting crude product (95%) was purified by flash chromatography (dichloromethane) to afford white crystals 141 (90%): m.p. 102–103° C., which was analyzed by NMR.

1. customequipped with a stirring bar
2. customthe mixture was transferred to a separatory funnel
3. customThe organic layer was separated
4. customevaporated in vacuo
5. customwater (6 mL), and the ether layer was separated
6. washwashed with water (3×3.0 mL)
7. dry with materialThe organic layer was dried (Na2SO4)
8. filtrationfiltered
9. customevaporated in vacuo
10. customThe resulting crude product (95%) was purified by flash chromatography (dichloromethane)