反应详情

To a stirred mixture of 3′,5′-difluoroacetophenone (86.8 g, 0.556 mol) and 2 M NH3 in EtOH (1.4 L, 2.8 mol) was added titanium(IV) isopropoxide (326 mL, 1.11 mol) dropwise over 15 min stirring was continued at ambient temperature for 20 h. The mixture was cooled in an ice-water bath and sodium borohydride (31.5 g, 0.834 mol) was added in portions over 60 min. The reaction mixture was stirred for an additional 1 h, and then quenched with aqueous NH4OH (2 M, 1.3 L) followed by EtOAc (1 L). The resulting mixture was aged for 18 h and filtered through a pad of celite, washing with EtOAc (1 L). To the filtrate was added EtOAc (2 L) and H2O (1 L) containing NaCl (ca. 100 g). The mixture was shaken and allowed to separate. The organic layer was concentrated in vacuo to a volume of about 500 mL and partitioned between EtOAc (2 L) and saturated aqueous Na2CO3 (300 mL). The organic layer was dried (Na2SO4), filtered, and concentrated in vacuo to give the title compound. MS: m/z=182 (M+CH3CN−NH2).

1. temperatureThe mixture was cooled in an ice-water bath
2. stirringThe reaction mixture was stirred for an additional 1 h
3. customquenched with aqueous NH4OH (2 M, 1.3 L)
4. waitThe resulting mixture was aged for 18 h
5. filtrationfiltered through a pad of celite
6. washwashing with EtOAc (1 L)
7. additionTo the filtrate was added EtOAc (2 L) and H2O (1 L)
8. additioncontaining NaCl (ca. 100 g)
9. stirringThe mixture was shaken
10. customto separate
11. concentrationThe organic layer was concentrated in vacuo to a volume of about 500 mL
12. custompartitioned between EtOAc (2 L) and saturated aqueous Na2CO3 (300 mL)
13. dry with materialThe organic layer was dried (Na2SO4)
14. filtrationfiltered
15. concentrationconcentrated in vacuo