1-oxidopyridin-1-ium

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-[3-(6-Bromo-hexyl)-2-(2-ethoxycarbonyl-ethyl)-phenoxy]-butyric acid ethyl ester (10.0 g, 21.2 mmol), pyridine N-oxide (10.06 g, 106 mmol), and sodium bicarbonate (10.0 g, 1 19 mmol) were heated at reflux with vigorous stirring in toluene (100 mL) for 24 hr. The mixture was cooled down and filtered. The filtrate was then evaporated under vacuo and the crude material was purified by column chromatography using 30% EtOAc-Hexane as eluant to give the title compound (7.0 g, 81%) as an oil. HR-MS-EI(+): calculated for C23H34O6 [M] 406.2350, found 406.2355. at reflux The mixture was cooled down filtered The filtrate was then evaporated under vacuo the crude material was purified by column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3.84 g (0.02 mole) of 5,6-dimethyl-2-mercaptomethylbenzimidazole and 1.9 g (0.02 mole) of pyridine N-oxide in 50 ml of acetic anhydride is heated to 100° C. for 4 hours. The acetic anhydride is evaporated off, the residue taken up with acetone and the mixture filtered and concentrated to a volume of 20 ml. From this solution, 2.6 g (48%) of 5,6-dimethyl-2-(2-pyridylthiomethyl)benzimidazole crystallize. The product thereby obtained is identical to that obtained by Method A, and the data for the identification appear in Tables 1 and 2. The acetic anhydride is evaporated off the mixture filtered concentrated to a volume of 20 ml From this solution, 2.6 g (48%) of 5,6-dimethyl-2-(2-pyridylthiomethyl)benzimidazole crystallize The product thereby obtained that obtained by Method A

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Synthetic Scheme XXVIII shows the 4-step preparation of the alkylating reagent 2-cyano-3-(4-bromomethylphenyl)pyridine (79) from 3-bromopyridine (80) (Aldrich). In step 1, the pyridine 80 was reacted with hydrogen peroxide in acetic acid at reflux to give the pyridine N-oxide 81. In step 2, the N-oxide 81 was converted to 3-bromo-2-cyanopyridine (82) by reaction with trimethysilylcyanide and triethyl anine in acetonitrile at reflux. In step 3, the nitrile 82 was coupled with 4-methylphenylboronic acid (56) (Scheme XXIV) using Snieckus conditions (Scheme XIII) to give 2-cyano-3-(4-methylphenyl) pyridine (83). In step 4, 83 was brominated with NBS/AIBN in carbon tetrachloride at reflux to give the desired alkylating reagent 79. ##STR91## at reflux

Conditions: temp:0.00; pressure:0.00; stir: