Determination of the antiallergenic agent, N-[4-(1H-imidazol-1-yl)butyl]-2-(1-methylethyl)-11-oxo-11H- pyrido [2,1-b]quinazoline-8-carboxamide, in plasma by reversed-phase high-performance liquid chromatographic analysis using fluorometric detection

A rapid, sensitive and selective high-performance liquid chromatographic (HPLC) assay was developed for the determination of the antiallergenic compound N-[4-(1H-imidazol-1-yl)butyl]-2-(1-methylethyl)-11-oxo-11H-pyrido[ 2,1-b] quinazoline-8-carboxamide (I), and its major metabolite, 2-(1-methylethyl)-11-oxo-11H-pyrido[2,1-b] quinazoline-8-carboxylic acid (I-A), in plasma. The assay involves precipitation of the plasma proteins with acetonitrile--methanol (9:1), followed by the analysis of an aliquot of the protein-free filtrate by reversed-phase ion-pair HPLC with fluorescence detection for quantitation. The analogous compound, N-[6-(1H-imidazol-1-yl)hexyl]-2-(1-methylethyl)-11-oxo-11H-pyrido [2,1-b]-quinazoline-8-carboxamide (II), is used as the internal standard. The overall recovery of compounds I and I-A from plasma is 107.0 +/- 8.6% and 107.0 +/- 10.0%, respectively. The sensitivity limits of quantitation are 20 ng of I, and 10 ng of I-A per ml of plasma using a 0.5-ml aliquot. The assay was used to monitor the plasma concentrations of I and of I-A in a dog following a 5 mg/kg intravenous infusion of I . 2HCl, a 10 mg/kg oral dose of I . 2HCl and of metabolite I-A.     

Synthesis of 6-[[(hydroxyimino)phenyl]methyl]-1-[(1-methylethyl)sulfonyl]-1H-imidazo[4,5-b]pyridin-2-amine. An aza analogue of enviroxime

6-[[(Hydroxyimino)phenyl]methyl]-1-[(1-methylethyl)sulfonyl]-1H-imidazo[4,5-b]pyridin-2-amine ( 1 ), an aza analogue of enviroxime, was synthesized in eight steps from 6-hydroxynicotinic acid ( 2 ). Acid 2 was nitrated, chlorinated with phosphorus pentachloride, and subjected to Friedel-Crafts aroylation to give 6-chloro-5-nitro-3-pyridyl phenyl ketone ( 5 ). Amination of 5 was followed by reduction of the nitro group and condensation with ethoxycarbonylisothiocyanate to give 6-benzyl-2-ethoxycarbonylamino-1H-imidazo[4,5-d]pyridine ( 8 ). The ethoxycarbonyl moiety of 8 was cleaved, N-1 was isopropylsulfonylated, and the carbonyl moiety was condensed with hydroxylamine to give 1 . Compound 1 was inactive against rhinovirus 1B and poliovirus type 1 .     

Copper complexes of 1-[(2-carboxyethyl)benzene]-3-[2-pyridine]triazene

The triazenide, 1-[(2-carboxyethyl)benzene]-3-[2-pyridine]triazene (HL), has been synthesized. In the presence of Et₃N, the reaction of HL with Cu(OAc)₂·H₂O or CuCl₂·2H₂O gives the tetranuclear copper(II) complexes {Cu₄(L)₂(μ₂-OH)₂(OAc)₄} 1 and {Cu₄L₄(μ₄-O)Cl₂} 2, respectively. The X-ray crystal structures of both complexes have been obtained. Magnetic studies indicate significant antiferromagnetic coupling between the copper(II) centers for both complexes, with coupling constants (J) of −493.4 cm⁻¹ for 1 and −165 cm⁻¹ for 2.     

Synthesis of 9-[(2-hydroxy-1-phosphonylethoxy)ethyl]guanine, 1-[(2-hydroxy-1-phosphonylethoxy)ethyl]cytosine and 9-[(2-hydroxy-1-phosphonylethoxy)ethyl] adenine

The acyclic nucleoside phosphonate analogues, 9-[(2-hydroxy-1-phosphonylethoxy)ethyl]guanine 6 , 1-[(2-hydroxy-1-phosphonylethoxy)ethyl]cytosine 7 and 9-[(2-hydroxy-1-phosphonylethoxy)ethyl]adenine 8 , have been prepared by the coupling of a tosylate of the phosphonate side chain 12 with a purine or pyrimidine base followed by deprotection of the blocking groups.     

New Synthesis of peri-Fused Tetrahydro[1,3]diazepino[1,2-a]benzimidazoles from 1-Aroylmethyl-2-[(4-hydroxybutyl)amino]benzimidazoles

Russian Journal of Organic Chemistry - Treatment of 2-[(4-hydroxybutyl)amino]-1H-benzimidazole with ω-bromoacetophenones gave 1-aroylmethyl-substituted derivatives which underwent cyclization...     

Gas chromatographic-mass spectrometric determination of two new antimycotic agents, 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole and 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole, in rabbit plasma following topical administration: a preliminary comparison with bifonazole

A method for the analysis of the antimycotic drugs 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole, 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole and bifonazole in rabbit plasma, employing gas chromatography-mass spectrometry with selected-ion monitoring, was developed. The procedure involved single-step purification of the biological matrix via liquid-liquid extraction on Extrelut columns and use of a carrier substance to minimize the negative effects of adsorption sites during the gas chromatographic process. The limits of detection ranged from 0.1 to 1.4 ng/ml, starting from a 200-microliter sample. The method was applied to a preliminary evaluation of percutaneous absorption of both drugs in the rabbit after a single administration, in comparison with bifonazole.