Manufacturing Process
10 parts by weight of isonicotinoyl hydrazine was dissolved in 200 by volume of methanol by stirring at 60°C. Then 11.2 parts 4-aminosalycylic acid was added at 60°C. On cooling a salt of both compounds crystallized as yellow prisms with MP: 135°-140°C (decomposed).
Isonicotinic acid hydrazide compound with 4-aminosalicylic acid may be prepared from the same components by using 750 parts of water by volume as a solvent.
10 parts 4-aminosalicylic acid was dissolved in 600 volume parts of water containing 39 parts by volume 2 N ammonium hydroxide. 9 parts by weight isonicotinoyl hydrazide was added and the mixture was heated to 30°C. The solution was acidified with 49 parts by volume of 2 N acetic acid. On cooling isonicotinic acid hydrazide compound with 4-amino-salicylic acid crystallized, which decomposed at 135°-140°C.
The yield was almost quantitative
