反应详情

Tin-Hydrochloric Acid Reduction of 6-Chloro-2,3-dihydro-1,3-dioxo-2-(2-pyridinylmethyl)-1H-isoindole-5-sulfonamide. A mixture of the above part (a) 1,3-dioxoisoindole (18 g., 0.051 mole), 120 ml. of methanol and 60 ml. of concentrated hydrochloric acid was heated with 30 mesh granulated tin metal added as indicated: 15 g. at 65°-70° for 6 hr., then 8 g. at 60°-65° for 16 hr. and finally 6 g. at 70°-75° for a 7 hr. period. The reaction mixture is cooled, filtered and concentrated to about 60 ml. volume. Addition of about 60 ml. of methanol to the concentrated mixture provided on standing 10 g., of a tin salt complex. This material was further purified by stirring with 1 liter of 50% methanol and 20 ml. of 1N hydrochloric acid while slowly introducing a gaseous stream of hydrogen sulfide (H2S) during a 1 hr. period at 45°-50°. The mixture is stirred at 40°-45° for 16 hr. and then concentrated slightly to remove excess H2S. Activated charcoal was added and the mixture filtered. Concentration of the filtrate to about 50 ml. and dilution with 1 ml. of 6N hydrochloric acid and cooling yielded 2.2 g. (12%) of white solid. Crystallization from aqueous methanol afforded analytically pure 6-chloro-2,3-dihydro-3-oxo-2-(2-pyridinylmethyl)-1H-isoindole-5-sulfonamide as the hydrochloride salt, m.p. 264°-266°.

1. additionadded
2. waitat 60°-65° for 16 hr
3. waitat 70°-75° for a 7 hr
4. temperatureThe reaction mixture is cooled
5. filtrationfiltered
6. concentrationconcentrated to about 60 ml
7. additionAddition of about 60 ml
8. customof methanol to the concentrated mixture provided
9. customThis material was further purified
10. additionof 1N hydrochloric acid while slowly introducing a gaseous stream of hydrogen sulfide (H2S) during a 1 hr
11. customat 45°-50°
12. stirringThe mixture is stirred at 40°-45° for 16 hr
13. concentrationand then concentrated slightly
14. customto remove excess H2S
15. additionActivated charcoal was added
16. filtrationthe mixture filtered
17. temperatureof 6N hydrochloric acid and cooling
18. customyielded 2.2 g
19. customCrystallization from aqueous methanol