Synthesis of sodium hypobromite
A cold solution of sodium hypobromite is prepared from 1.6 g. of sodium hydroxide, 3.2 g of bromine, and 10 g of ice and water. To this solution is added with stirring 1-[7-chloro-4,10-dihydro-1-methyl-10-oxo-1Hbenzoxepino[4,3-b]pyrrole-2-yl]propan-2-one (Q) (1.5 g, 0.005 m), while keeping the temperature below 10° C.
The resulting mixture is stirred at low temperature for an additional 4 hours before water and ether are added. The layers are separated and the aqueous layer is treated with a sufficient amount of sodium bisulfite. The treated aqueous layer is filtered and the filtrate acidified with 2 N hydrochloric acid to give crude 7-chloro-4,10-dihydro-1-methyl-10-oxo-1Hbenzoxepino[4,3-b]pyrrol-2-acetic acid.
Literature source US04440779