Ethyl Acetate → 3,8-Dibromoquinolin-6-amine

Participants

Reaction Steps

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.

Provenance & Evidence