Boron tribromide → Erbstatin

To a stirred solution of (E)-N-[2-(2,5-dimethoxyphenyl) ethenyl] formamide (2.071 g, 10 mmol) in anhydrous dichloromethane (100 ml) is added, at -78° C. under nitrogen over a period of 10 min, a 1.0M solution of boron tribromide in dichloromethane (30 ml, 30 mmol). The resulting mixture is stirred for another 1 h at -78° and then allowed to warm to room temperature. After stirring for 1.5 h at 20°-25° C. the mixture is cooled to -10° C. and then quenched by the dropwise addition of water (100 ml) over a 10 min period. After addition of ethyl acetate (100 ml) the organic layer is separated, washed with water, dried with Na2SO4 and evaporated under vacuum to dryness. After venting with nitrogen the residue is dissolved in 80 ml of CHCl3 /MeOH 10% and the solution diluted with CHCl3 (60 ml) to faint turbidity. The mixture is kept for 5 h at 0°-5° C., the precipitate filtered and dried at 20°-25° C. under vacuum. Thus 14.34 g (80% yield) of pure title compound is obtained with m.p. 149°-153° C.

1. stirringAfter stirring for 1.5 h at 20°-25° C. the mixture
2. temperatureis cooled to -10° C.
3. customquenched by the dropwise addition of water (100 ml) over a 10 min period
4. additionAfter addition of ethyl acetate (100 ml) the organic layer
5. customis separated
6. washwashed with water
7. dry with materialdried with Na2SO4
8. customevaporated under vacuum to dryness
9. dissolutionis dissolved in 80 ml of CHCl3 /MeOH 10%
10. additionthe solution diluted with CHCl3 (60 ml) to faint turbidity
11. waitThe mixture is kept for 5 h at 0°-5° C.
12. filtrationthe precipitate filtered
13. customdried at 20°-25° C. under vacuum

ORD record

ord-a7358820a09c43689bacc869d465c441

Source dataset

uspto-grants-1992_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05130472