Novel synthesis of 2-[18F]-fluoroisonicotinic acid hydrazide and initial biological evaluation.

2-[18F]-Fluoroisonicotinic acid hydrazide was synthesized by nucleophilic displacement reaction on ethyl-2- (trimethylammonium)-isonicotinate precursor in acetonitrile. Kryptofix 222 was used as the phase transfer catalyst. The intermediate fluorinated ethyl ester reacted with hydrazine hydrate to produce the hydrazide in excellent radiochemical yield. The overall radiochemical yield was greater than 70% with total synthesis time of approximately 60 minutes. Biological evaluation was performed in bacterial cells and biodistribution in normal CBA/J mice. It was found that the S. pneumoniae cells retained the radiotracer in an in vitro assay.