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In this work, carbon-nanotube-assisted electromembrane extraction in the two-phase mode combined with GC was developed for the preconcentration and determination of basic drugs in body fluids. The multiwalled carbon nanotubes dispersed in organic solvent are held in the pores of the porous fiber wall by capillary forces and sonification. The membrane with immobilized carbon nanotubes acts as a sorbent and provides an additional pathway for analyte transport. This study demonstrates that the immobilization of carbon nanotubes in the supported liquid membrane is an excellent approach to enhance the performance of the extraction. Optimization of the variables affecting this method was carried out in order to achieve the best extraction efficiency. Optimal extractions were accomplished with octanol as the extraction solvent, 50 V as the driving force and pH 7.4 in the sample solution with the whole assembly agitated at 1000 rpm for 20 min. Under the optimized extraction conditions, the proposed technique provided good linearity (R(2) > 0.9990), repeatability (3.5-3.8%), low LODs (1.5 ng/mL), good preconcentration factors (292-316) and high recoveries (80-87%). Finally, this method was successfully used for the determination of tramadol and methadone in different body fluids including plasma and urine samples.

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Thio-and thiazoloquinazolinones were synthesized efficiently by the anodic oxidation of catechols in the presence of 2-mercapto-4(3H)-quinazolinone in aqueous solution. 4-Methylcatechol and 3-methoxycatechol convert into thioquinazolinones via an EC (E: electron transfer, C: chemical reaction) pathway. Catechol, 3-methylcatechol, and 3,4-dihydroxybenzoic acid convert into thiazoloquinazolinones via an ECEC pathway.Quinazolinone A and its derivatives ( Figure 1) are known to have a broad range of pharmaceutical properties, such as anticancer, anti-inflammatory, anticonvulsant, and antidiuretic activities. 1-7 The presence of the thiazole ring in many natural and synthetic quinazolinones has generated interesting biological properties. 8,9 Moreover, thiazolo[2,3-b]quinazolinones B (Figure 1) are potentially interesting from a biological and synthetic point of view. A number of classic methods for the preparation of thiazoloquinazolinones have been developed. These include the reaction of heteroaromatic 2-aminoesters with 2-(methylthio)-2-thiazoline, 10 solid-phase methods, 11 condensation of o-aminobenzoic acid hydrochloride with the appropriate a-or w-thiocyanato ketone, 12 condensation of substituted anthranilic acids or esters with methyl 2-chlorothiazole-5-carboxylate, 13 reaction of anthranilic acid with 2-chlorobenzothiazole, and the reaction of ethylanthranilate with 2-chlorobenzothiazole. 14,15