反应详情

150 mg (0.28 mmol) of the compound of Example 20, 89 mg (0.34 mmol) of tert-butyl 3-[(methyl-sulphonyl)oxy]pyrrolidine-1-carboxylate [lit. e.g.: P. Kocalka et al., Tetrahedron 2006, 62 (24), 5763-5774] and 201 mg (0.62 mmol) of caesium carbonate in 3 ml of DMF were heated at 90° C. for 6 h. The reaction was then stirred into 15 ml of 0.1 M aqueous sodium hydroxide solution and the mixture was stirred at RT for another 10 min. The precipitate formed was filtered off, washed with water and dried under reduced pressure. The intermediate obtained in this manner was stirred in 3 ml of dichloromethane and 1 ml of trifluoroacetic acid at RT for 1 h. The mixture was then concentrated under reduced pressure and the residue was purified by preparative HPLC (Method 18). After concentration of the product-containing fractions, the residue was dissolved in ethyl acetate and washed successively with saturated potassium carbonate solution and saturated sodium chloride solution. The organic phase was dried over sodium sulphate, filtered and concentrated under reduced pressure. Drying of the residue gave 101 mg (90% pure, 60% of theory) of the title compound.

1. customThe precipitate formed
2. filtrationwas filtered off
3. washwashed with water
4. customdried under reduced pressure
5. customThe intermediate obtained in this manner
6. concentrationThe mixture was then concentrated under reduced pressure
7. customthe residue was purified by preparative HPLC (Method 18)
8. dissolutionAfter concentration of the product-containing fractions, the residue was dissolved in ethyl acetate
9. washwashed successively with saturated potassium carbonate solution and saturated sodium chloride solution
10. dry with materialThe organic phase was dried over sodium sulphate
11. filtrationfiltered
12. concentrationconcentrated under reduced pressure
13. customDrying of the residue