反应详情

5-bromo-2-(2,5-dimethyl-pyrrol-1-yl)-pyridine (1.5 g 5.9 mmol) was azeotroped with toluene and dissolved in THF (20 ml). This mixture was cooled to −78 C. and t-butyllithium (1.7M in pentane, 7 ml, 11.9 mmol) was added maintaining the temperature below −70 C. The material from example 62 was dissolved in THF (20 ml) and added to the mixture immediately on completion of the t-butyllithium addition. The mixture was allowed to stir at −78° C. for 30 minutes at which time NH4Cl (10% aq, 150ml) was added and the mixture extracted into EtOAc (200 ml), dried with magnesium sulphate, filtered and evaporated. Flash chromatography on SiO2 eluting with a stepped gradient from 25% EtOAc/pentane to 50% EtOAc/pentane gave the title compound as mixture of diastereoisomers in approximately 3.5:1 ratio as a yellow oil (480 mg).

1. temperatureThis mixture was cooled to −78 C
2. temperaturemaintaining the temperature below −70 C
3. additionwas added
4. extractionthe mixture extracted into EtOAc (200 ml)
5. dry with materialdried with magnesium sulphate
6. filtrationfiltered
7. customevaporated