Pyridine extract characterization

CHARACTERIZATION of the PYRIDINE-EXTRACT. Pyridine is known to cling to coals. The extract was therefore stirred with a methanol/water/HCl mixture for two days as suggested by Buchanan.(lS) Elemental analysis of the extract revealed 1.85% N. The original coal contained 1.92% N (daf) so it is apparent that the methanol/water/HCl treatment followed by drying successfully removed pyridine from the extract. The FTIR spectrum of the extract did not reveal the presence of pyridine. 

In general terms, lignite and anthracite coals appear to contain much lower proportions of the volatile organic componnds (10) than the bituminous coals, although alkaline extraction of lignite (and bituminous coal) will yield organic acids of various types that can be characterized. On the other hand, the hexane-soluble portion of the pyridine extracts that were obtained at 50°C (120°F) from coal (carbon content 83.6% w/w) have been identified as alkylated chrysenes as well as alkylated picenes in addition to a mixture of C2g, C29, and C30 paraffins. There were also indicates of the presence of an alicyclic or methyl-substituted five-ring (cat-condensed) system as well as l,2,5,6-dibenzanthracene(s) (Table 10.1). 

Methyl isocyanate (1.14 g, 20 mmol) was dissolved in 70% HF/pyridine (20 mL) in a polyethylene bottle at 0 C. The mixture was then stirred at rt for 24 h and extracted with CHC1, the CHC13 was then carefully removed by distillation on a rotary evaporator. The residue was distilled under reduced pressure yield 0.6 g (40%) bp 48 50 C/6 Torr the product was characterized by H NMR and IR spectroscopy. 

Harman itself is the most abundant alkaloid found in the plants studied. As an example, it represents about 16, 8, and 5% of the alkaloids extracted from the root bark, trunk bark, and leaves, respectively, of P. Lyallii. Along with the harman compounds, the substituted pyridine 6, already characterized by McLean and Murray (77), has been isolated from P. Lyallii. 

In another method for isolating the carbohydrate fraction of wood, chlorine dioxide is used, instead of chlorine, and the lignin derivatives formed are extracted out with pyridine-water. This method was first reported by Schmidt and Graumann. Several years later, Jayme modified the procedure by using sodium chlorite and acetic acid in place of the explosive, chlorine dioxide gas. Jayme s method was subsequently modified by Wise and coworkers, " and, in this form, has been used extensively in the characterization of wood. The procedure may be applied directly to air-dried wood without previous extraction, except in the case of resinous woods, where a preliminary treatment with alcohol and ether is desirable. 

Unchanged Ticlopidine (25) and three metabolites Ticlopidine N-oxide, (T-NO), Tetrahydrothieno pyridine (THTP), and 2,chloro-hyppuric acid (CI-HPA) were isolated from rat urine by differencial solvent extraction and characterized by their behaviour on TLC and GLC. Their identities were confirmed by comparison with authentic standards. A fourth metabolite (T-M) gave rise upon acid hydrolysis to a compound, which co-chromatographed with authentic (T), both on TLC and GLC. The original structure of this metabolites is not yet elucidated. (T) and (T-M) were also found in bile wxtracts, whereas (T-NO), (THTPj, and (CL-HPA) were not detected in the bile, under the conditions used. 

Preparation of sulfonamide 4 A mixture of thiol compound (1 2 mmol), 30% hydrogen peroxide (6 mmol, 0.6 mL) and thionyl chloride (2 mmol, 0.14 mL) was stirred in acetonitrile at room temperature for an appropriate time. After completion of the reaction as indicated by TLC, a solution of amine (3 2 mmol) in pyridine (1 mL) was added to the reaction mixture. The resulting mixture was then continued to stir at room temperature until completion of the reaction. On completion of the reaction, the resulting mixture was acidified with 2 N HCl solution, and extracted with EtOAc. The organic layer was washed with water and brine, and dried over magnesium sulfate. The filtrate was evaporated to obtain pure sulfonamide derivative 4 crystalline solid. Recrystallization from a mixture of ethanol and water afforded analytically pure product. AU the products were characterized by analytical and spectral studies. 

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