反应详情

Add slowly a solution of sodium nitrite (1.40 g, 20.3 mmol) in water (11 mL) to a flask containing 2,2-difluoro-benzo[1,3]dioxol-5-ylamine (3.41 g, 19.7 mmol), water (14 mL), and concentrated hydrochloric acid (5 mL) at −5° C. Cool the reaction to −10° C. then add tin(II) chloride (11.20 g, 49.6 mmol) in concentrated hydrochloric acid (9 mL). Stir the reaction for one hour and collect the resultant solid by filtration. Dissolve the solid in methylene chloride (20 mL) and treat with acetone (5 mL). Wash the resultant organic solution with water (50 mL), dry over magnesium sulfate, filter, and evaporate under reduced pressure. Stir the resultant oil with 2N hydrochloric acid (100 mL) for 12 h. Collect a solid by filtration, wash with water and dry in a vacuum oven at 40° C. overnight to give the subtitled compound (1.14 g, 26%) as a red powder. 1H NMR (300 MHz, DMSO-d6): δ 10.32 (br s, 3H), 8.45 (br s, 1H), 7.34 (d, J=8.7 Hz, 1H), 7.11 (d, J=2.3 Hz, 1H), 6.79 (dd, J=8.7, 2.3 Hz, 1H).

1. temperatureCool
2. customthe reaction to −10° C.
3. customthe reaction for one hour
4. customcollect the resultant solid
5. filtrationby filtration
6. dissolutionDissolve the solid in methylene chloride (20 mL)
7. additiontreat with acetone (5 mL)
8. washWash the resultant organic solution with water (50 mL)
9. dry with materialdry over magnesium sulfate
10. filtrationfilter
11. customevaporate under reduced pressure
12. stirringStir the resultant oil with 2N hydrochloric acid (100 mL) for 12 h
13. customCollect a solid
14. filtrationby filtration
15. washwash with water
16. customdry in a vacuum oven at 40° C. overnight