反应详情

Diethyl azodicarboxylate (13.4 g) was added over a period of 20 minutes to a stirred solution of 4-bromophenol (12 g), 2-methylthioethanol (6.4 g) and triphenylphospine (18.2 g) in tetrahydrofuran (250 ml) at -5° C. under an atmosphere of argon. The mixture was stirred at ambient temperature for 1 hour and the solvent was then removed by evaporation. The residue was partitioned between dichloromethane (150 ml) and water (150 ml). The aqueous phase was separated and extracted with dichloromethane (150 ml). The dichloromethane extracts were combined, washed with water (2×100 ml), dried (MgSO4) and evaporated. The residue was dissolved in a boiling mixture of toluene (50 ml) and n-heptane (50 ml). The solution was chilled and the precipitated triphenylphosphine oxide removed by filtration. The filtrate was evaporated and purified by medium pressure chromatography on silica gel using a 1:1 (v/v) mixture of toluene/n-heptane as eluent to give 1-(4-bromophenoxy)-2-methylthioethane as an oil (10.2 g); NMR(CDCl3): 2.2(3H,s), 2.88(2H,t), 4.12(2H,t), 6.77(2H,d) and 7.37(2H,d).

1. customthe solvent was then removed by evaporation
2. customThe residue was partitioned between dichloromethane (150 ml) and water (150 ml)
3. customThe aqueous phase was separated
4. extractionextracted with dichloromethane (150 ml)
5. washwashed with water (2×100 ml)
6. dry with materialdried (MgSO4)
7. customevaporated
8. dissolutionThe residue was dissolved in a boiling mixture of toluene (50 ml) and n-heptane (50 ml)
9. temperatureThe solution was chilled
10. customthe precipitated triphenylphosphine oxide removed by filtration
11. customThe filtrate was evaporated
12. custompurified by medium pressure chromatography on silica gel using
13. additiona 1:1 (v/v) mixture of toluene/n-heptane as eluent