Study On The Separation And Determinations Of 5-halonicotinic Acids And Ethyl 5-halonicotinates With HPLC

Halo-substituted nicotinic acid and its derivatives, which have special characters and various pharmaceutical activities, have a broad foreground of application. These compounds can inhibit cozymase synthesis from cozymase precursors and lead to a 'lethal synthesis'. These compounds are widely used as anti-lipolytic agents because of its activity in reducing free fatty acids and cholesterol in serum. Halo-substituted nicotinic acid and its derivatives can effect on isoprenaline-induced myocardial necrosis and protecte heart. These compounds can be utilized to synthesize a novel chemical delivery system, and so on.The dissertation was mainly focused on the determination of three 5-halonicotinic acids and their ethyl esters, which include 5-bromonicotinic acid, ethyl 5-bromonicotinate, 5-chloronicotinic acid, ethyl 5-chloronicotinate, 5-fluoroicotinic acid and ethyl 5-fluoronicotinate, with HPLC-UV method.The HPLC with UV detector at 279 nm was applied to determination of 5-bromonicotinic acid and ethyl 5-bromonicotinate on a C18 column using acetonitrile and 0.005mol/L KH₂PO₄ (75 + 25) as a mobile phase. The RSD, average recovery, linear concentration range of 5-bromonicotinic acid were 1.6 %, 99.4%, 0.050-3.40 mg/ml (r = 0.9996), and that of ethyl 5-bromonicotinate were 0.82%. 100.1%, 0.13-6.50 mg/ml (r = 0.9999). respectively. The HPLC with UV detector at 277 nm was applied to determination of 5-chloronicotinic acid and ethyl 5-chloronicotinate on a C18 column using methanol and 0.01mol/L KH₂PO₄ (75 + 25) as a mobile phase. The RSD, average recovery, linear concentration range of 5-chloronicotinic acid were 1.7 %, 99.2%, 0.030-1.40 mg/ml (r = 0.9995), and that of ethyl 5-chloronicotinate were 1.5%, 99.7%, 0.017-0.54 mg/ml (r = 0.9999), respectively. The HPLC with UV detector at 271 nm was applied to determination of 5-fluoronicotinic acid and ethyl 5-fluoronicotinate on a C18 column using methanol and 0.025mol/L KH₂PO₄ (75 + 25) as a mobile phase. The RSD, average recovery, linear concentration range of 5-fluoronicotinic acid were 1.9 %, 99.1%, 0.05-1.50...