Sodium Hydroxide → HCID 178524411, compound

Participants

Reaction Steps

Sodium hydroxide, 336 g of 50% solution (4.2 mole) in 1 kg of ice was treated with bubbling chlorine gas while stirring until 78 g (1.1 mole) of chlorine was taken into the solution. To the resulting cold, basic sodium hypochlorite solution was added 142 g (1.0 mole) of 2-hydroxynicotinic acid in one portion. Within 1/2 hr the temperature had risen to 35° C. and dissolution had occurred. The mixture was stirred overnight after which time 13CNMR analysis indicated the ratio of starting material to desired product (as the disodium salt) was about 30:70%. Another solution of basic sodium hypochlorite was prepared by the above procedure by absorbing 35 g (0.5 mole) of chlorine gas in a mixture of 100 g of 50% solution (1.25 mole) of sodium hydroxide and 278 g of ice. This hypochlorite solution was added to the main reaction mixture and stirring was continued overnight. 13CNMR analysis indicated the starting 2-hydroxynicotinic acid had all reacted and the desired 5-chloro-2-hydroxynicotinic acid was present as the disodium salt. Sodium bisulfite, 14 g was added and stirring was continued for 1.5 hr. The reaction mixture was gradually added to a cooled, stirred solution of 337 ml of concentrated (37%) hydrochloric acid. The maximum temperature of the acidified mixture was 25° C. The yield of title compound on separation and drying was 146 g (84%).

Provenance & Evidence