2-Fluoroisoniazid and para-aminosalicylic acid isoniazid have become alternative drugs, but the vast majority of doctors still consider 2-fluoroisoniazid an indispensable primary drug for the treatment of tuberculosis. It is considered a first-line anti-tuberculosis drug, along with rifampicin, ethambutol, streptomycin, and pyrazinamide.
To 2000ml three-necked bottle add 1.62mol 2-fluoroisonicotinic acid, 1200g ethanol, 16.4g (0.162mol) triethylamine, stirring to lower the temperature to 0 C ~ 5 C, slowly drop 212g (1.78mol) sulfoxide chloride, dropletting is completed, controlled temperature 0 C ~ 5 C insulation for 2 hours, and then warmed up to 20 C ~ 25 C insulation for 20 hours, the reaction is complete, the Decompression concentration of the oil, will be 119g (2.43mol) hydrazine hydrate to add, warming to 70 ~ 75 , holding 10 hours, add diluent (water 350g), appropriate warming, dissolution, to get aqueous solution of 2-fluoroisonicotinic acid hydrazide crude, add 10g of activated charcoal, 70 ~ 75 holding time of half an hour, filtration, filtrate is naturally cooled for 6 hours, and then slowly cooled to 0 , filtration The filtrate was naturally cooled for 6 hours, then slowly cooled to 0C, filtered and dried to obtain the finished product of isoniazid with the purity of 99.94%, the single impurities were all less than 0.10%, the impurity J was not detected, and the total yield of 2-fluoroisonicotinic acid hydrazide was 86%.
