Hydrochloric Acid → Methyl 2-(chlorosulfonyl)-6-fluorobenzoate

Participants

Reaction Conditions

Reaction Steps

At 5° C. and while stirring, 108 g (0.64 mol) of methyl 6-fluoroanthranilate and 45 g (0.65 mol) of sodium nitrite in 106 ml of water were added separately but simultaneously over a period of 1 hour in such a manner to 250 ml of concentrated hydrochloric acid that the ester component was in an excess. After the reaction mixture had been stirred for 20 minutes at 5 to 8° C., it was poured all at once into a prepared solution of 53 g of sulfur dioxide, 1.7 g of copper (II) chloride in a small amount of water and 200 ml of 1,2-dichloroethane, and stirred for a further 10 minutes. The mixture was heated slowly to 50° C. and stirred for ninety minutes while passing in 46 g of sulfur dioxide. The mixture was then cooled to 20° C. and 5.5 g of chlorine was passed in over a 20-minute period while stirring. The organic phase was then separated, washed with water and dried. There was obtained 65% of theory of the title compound as a brownish oil.

Provenance & Evidence