Manufacturing Process
4-Chloro-2-hydroxy-benzoic acid n-butyl-amide
A mixture consisting of 114 g of 4-chloro-2-hydroxy-benzoic acid n-butylester,
64 grams of methanol and 130 g of n-butyl-amine is heated for 22
hours at 80°C; then the parts volatile up to 130°C are distilled off under
reduced pressure. The residue crystallizing in the cold is dissolved in 200 ml
of methanol and the solution obtained is slowly added dropwise and while
stirring into dilute hydrochloric acid, if necessary, after treatment with animal
charcoal. The precipitate which is at first semi-solid soon crystallizes
completely. It is filtered with suction, washed with dilute hydrochloric acid,
then thoroughly washed again with water, and the product obtained in good
yield is dried in the air. After having been recrystallized twice from carbon
tetrachloride the 4-chloro-2-hydroxybenzene acid n-butylamide melts at 90-
92°C.
