反应详情

A solution of 5.85 g (25 mmole) of 4-azidomethyl-2'-cyanobiphenyl (from Step A) in 50 ml of dry tetrahydrofuran was treated portionwise with 6.55 g (25 mmole) of triphenylphospine over 3-4 minutes. The solution was stirred at ambient temperature under N2, and gas evolution proceeded at a moderate rate. A mild exotherm occurred, and the solution was cooled in a water bath as necessary. After 2 hours, by which time gas evolution had ceased, 675 μl (37.5 mmole) of H2O was added, and stirring was continued at room temperature under N2. After 22 hours, the solution was concentrated in vacuo, and the residual oil was chromatographed on a column of silica gel (gradient elution with 2-10% methanol in CH2Cl2). The residue from evaporation of the pooled product fractions was partitioned between ether-CH2Cl2 and saturated Na2CO3 (aqueous). The organic phase was dried (Na2SO4), filtered, and concentrated in vacuo to yield 4.64 g (89%) of air-sensitive, nearly white crystals, mp 54°-55° C., homogeneous by TLC in 9:1 CH2Cl2 --MeOH; mass spectrum (FAB) m/e 209(M+1)+.

1. temperaturethe solution was cooled in a water bath as necessary
2. stirringstirring
3. customwas continued at room temperature under N2
4. waitAfter 22 hours
5. concentrationthe solution was concentrated in vacuo
6. customthe residual oil was chromatographed on a column of silica gel (gradient elution with 2-10% methanol in CH2Cl2)
7. customThe residue from evaporation of the pooled product fractions
8. customwas partitioned between ether-CH2Cl2 and saturated Na2CO3 (aqueous)
9. dry with materialThe organic phase was dried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customto yield 4.64 g (89%) of air-sensitive, nearly white crystals, mp 54°-55° C.