反应详情

3,8-Dibromo-6-nitroquinoline (48.5 g, prepared as described in J Am Chem Soc (1955), 77, 4175-4176) was suspended in concentrated hydrochloric acid (400 ml) at ambient temperature and iron powder (27 g, reduced by hydrogen) was added in portions allowing the reaction temperature to rise to 73° C. during the additions. The bright yellow suspension that was initially produced became dark brown during the final stages of the reaction. The mixture was cooled to 0° C. and basified with aqueous sodium hydroxide (10M) until the reaction was at pH10. Ethyl acetate was added to the suspension and the mixture was thoroughly mixed then filtered through a bed of kieselguhr. The organic fraction was separated and the aqueous fraction re-extracted with further ethyl acetate. The insoluble material that was filtered from solution was further extracted with hot acetone and the organic fractions combined, washed with aqueous sodium hydrogen carbonate, dried over sodium sulphate and evaporated under reduced pressure to give 6-amino-3,8-dibromoquinoline as a brown solid, 34.7 g.

1. customto rise to 73° C. during the additions
2. customThe bright yellow suspension that was initially produced
3. customstages of the reaction
4. additionthe mixture was thoroughly mixed
5. filtrationthen filtered through a bed of kieselguhr
6. customThe organic fraction was separated
7. extractionthe aqueous fraction re-extracted with further ethyl acetate
8. filtrationThe insoluble material that was filtered from solution
9. extractionwas further extracted with hot acetone
10. washwashed with aqueous sodium hydrogen carbonate
11. dry with materialdried over sodium sulphate
12. customevaporated under reduced pressure