反应详情

温度

30 °C

A solution of 2-(2-methyl-4-nitrophenylimino)-3-thia-1-azaspiro[4.4]nonane (Method C2a; 33.2 g, 114 mmol) in DMF (1 L) was treated with NaOH (690 g, 17.3 mol) and cyclopentyl bromide (865 mL, 6.3 mol) and the resulting mixture was stirred at 20-40° C. for 18 h, then cooled to 4° C., and treated with water (1.5 L). A conc. HCl solution was added to adjust the pH to 0, and the mixture was extracted with EtOAc (80 mL). The organic phase was washed with a 1N HCl solution (1 L), dried (MgSO4) and concentrated under reduced pressure. The residue was dissolved in CH2Cl2 (500 mL) and filtered through a pad of silica gel (9×4 cm). Hexane was added to the resulting solution and volatiles were slowly removed by partial vacuum until crystals formed. The solids were collected to yield 1-cyclopentyl-2-(2-methyl-4-nitrophenylimino)-3-thia-1-azaspiro[4.4]nonane as yellow crystals (10.9 g, 26%): mp 118-9° C.; TLC (5% EtOAc/hex) Rf0.34.

1. temperaturecooled to 4° C.
2. extractionthe mixture was extracted with EtOAc (80 mL)
3. washThe organic phase was washed with a 1N HCl solution (1 L)
4. dry with materialdried (MgSO4)
5. concentrationconcentrated under reduced pressure
6. dissolutionThe residue was dissolved in CH2Cl2 (500 mL)
7. filtrationfiltered through a pad of silica gel (9×4 cm)
8. additionHexane was added to the resulting solution and volatiles
9. customwere slowly removed by partial vacuum until crystals
10. customformed
11. customThe solids were collected