1-(1-oxidopyridin-1-ium-4-yl)ethanone

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

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

Procedure: A mixture of 5.48 gm (0.04 mole) of 4-acetylpyridine 1-oxide, 4.09 gm (0.04 mole) of butyric acid hydrazide and 100 ml of absolute ethanol is refluxed 6 hours. The reactions mixture is evaporated in vacuo to give a solid. The crude product is crystallized from ethyl acetate/ethanol to yield 7.41 gm (84%) of the title compound; mp 209.7°. is refluxed 6 hours The reactions mixture is evaporated in vacuo to give a solid The crude product is crystallized from ethyl acetate/ethanol

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

Procedure: A mixture of 5.48 gm (0.04 mole) of 4-acetylpyridine 1-oxide, 5.68 gm (0.04 mole) of cyclohexanecarboxylic acid hydrazide and 100 ml of absolute ethanol is refluxed 4 hours. The reaction mixture is concentrated in vacuo to dryness to give a solid. The solid is crystallized from isopropanol to furnish 8.20 gm (79%) of the title compound; mp 245.3°. is refluxed 4 hours The reaction mixture is concentrated in vacuo to dryness to give a solid The solid is crystallized from isopropanol

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

Procedure: A mixture of 5.48 gm (0.04 mole) of 4-acetylpyridine 1-oxide, 5.68 gm (0.04 mole) of cyclohexanecarboxylic acid hydrazide and 100 ml of absolute ethanol is refluxed 4 hours. The reaction mixture is concentrated in vacuo to dryness to give a solid. The solid is crystallized from isopropanol to furnish 8.20 gm (79%) of the title compound; mp 245.3°. is refluxed 4 hours The reaction mixture is concentrated in vacuo to dryness to give a solid The solid is crystallized from isopropanol

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

Procedure: A mixture of 5.48 gm (0.04 mole) of 4-acetylpyridine 1-oxide, 5.45 gm (0.04 mole) of benzhydrazide and 100 ml of absolute ethanol is refluxed for a total of 4 hr and cooled. The reaction mixture is evaporated in vacuo to yield a solid which is crystallized from ethanol to yield 7.82 gm (77%) of the title compound having a melting point of 248.9° C. (decomp). is refluxed for a total of 4 hr cooled The reaction mixture is evaporated in vacuo to yield a solid which is crystallized from ethanol

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

Procedure: In a manner analogous to the preparation of the compound of Example 1, from 3,4,5-trimethoxyphenylguanidine nitrate (2.25 g, 7.81 mmol), 3-dimethylamino-1-(1-oxo-pyrid-4-yl)-2-propen-1-one (880 mg, 7.81 mmol) and sodium hydroxide (344 mg, 8.6 mmol) to give the title compound (1.2 g) as a green solid m.p. 220°. MS m/z 355 (M+H). The 3-dimethylamino-1-(1-oxopyrid-4-yl)-2-propen-1-one used as starting material was prepared by heating a solution of 4-acetylpyridine-N-oxide (2.5 g, 18.2 mmol) in dimethylformamide diethylacetal (30 ml) at reflux for 0.5 h. On cooling the resulting solid was collected and washed with diethyl ether to give the desired product (3.18 g) as an orange solid m.p. 181°. The 4-acetylpyridine-N-oxide was prepared by treating a solution of 4-acetylpyridine (3.0 g, 24.8 mmol) in CH2Cl2 with 3-chloro-peroxybenzoic acid [Aldrich 57-86%] (8.4 g) at room temperature for 12 h. The reaction was filtered, the filtrate concentrated under reduced pressure and the resulting residue subjected to column chromatography [silica 10% methanol-ethyl acetate] to give the desired product (3.2 g) as a white solid m.p. 101°. The reaction was filtered the filtrate concentrated under reduced pressure

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

Procedure: In a manner analogous to the preparation of the compound of Example 1, from 3,4,5-trimethoxyphenylguanidine nitrate (2.25 g, 7.81 mmol), 3-dimethylamino-1-(1-oxo-pyrid-4-yl)-2-propen-1-one (880 mg, 7.81 mmol) and sodium hydroxide (344 mg, 8.6 mmol) to give the title compound (1.2 g) as a green solid m.p. 220°. MS m/z 355 (M+H). The 3-dimethylamino-1-(1-oxopyrid-4-yl)-2-propen-1-one used as starting material was prepared by heating a solution of 4-acetylpyridine-N-oxide (2.5 g, 18.2 mmol) in dimethylformamide diethylacetal (30 ml) at reflux for 0.5 h. On cooling the resulting solid was collected and washed with diethyl ether to give the desired product (3.18 g) as an orange solid m.p. 181°. The 4-acetylpyridine-N-oxide was prepared by treating a solution of 4-acetylpyridine (3.0 g, 24.8 mmol) in CH2Cl2 with 3-chloro-peroxybenzoic acid [Aldrich 57-86%] (8.4 g) at room temperature for 12 h. The reaction was filtered, the filtrate concentrated under reduced pressure and the resulting residue subjected to column chromatography [silica 10% methanol-ethyl acetate] to give the desired product (3.2 g) as a white solid m.p. 101°. The reaction was filtered the filtrate concentrated under reduced pressure

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

Procedure: The 4-acetyl-pyridine N-oxide used is prepared in the following manner: 11.0 ml (100 mmol) of 4-acetyl-pyridine and 31.3 g (100 mmol) of 55% m-chloro-perbenzoic acid are boiled under RF for 16 h in 200 ml of methylene chloride. Precipitation with 200 ml of diethyl ether gives 4-acetyl-pyridine N-oxide; m.p. 132°-133°. The 4-acetyl-pyridine N-oxide used is prepared in the following manner Precipitation with 200 ml of diethyl ether

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

Procedure: 5.0 g (36.5 mmol) of 4-acetyl-pyridine N-oxide and 6.64 ml (73 mmol) of phosphorus oxychloride are stirred in 50 ml of toluene for 2 h at 100°. The reaction mixture is stirred at 50° into 500 ml of 10N sodium hydroxide solution, extracted with ethyl acetate and treated with Tonsil (Fluka; bentonite--colloidal aqueous aluminium silicate). Concentration and crystallisation (diethyl ether/n-hexane) give 4-acetyl-2-chloro-pyridine; extracted with ethyl acetate treated with Tonsil (Fluka; bentonite--colloidal aqueous aluminium silicate) Concentration and crystallisation (diethyl ether/n-hexane)

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

Procedure: The 4-acetyl-pyridine N-oxide used is prepared in the following manner: 11.0 ml (100 mmol) of 4-acetyl-pyridine and 31.3 g (100 mmol) of 55% m-chloro-perbenzoic acid are boiled under RF for 16 h in 200 ml of methylene chloride. Precipitation with 200 ml of diethyl ether gives 4-acetyl-pyridine N-oxide; m.p. 132°-133°. The 4-acetyl-pyridine N-oxide used is prepared in the following manner Precipitation with 200 ml of diethyl ether

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

Procedure: 5.0 g (36.5 mmol) of 4-acetyl-pyridine N-oxide and 6.64 ml (73 mmol) of phosphorus oxychloride are stirred in 50 ml of toluene for 2 h at 100°. The reaction mixture is stirred at 50° into 500 ml of 10N sodium hydroxide solution, extracted with ethyl acetate and treated with Tonsil (Fluka; bentonite--colloidal aqueous aluminium silicate). Concentration and crystallisation (diethyl ether/n-hexane) give 4-acetyl-2-chloro-pyridine; extracted with ethyl acetate treated with Tonsil (Fluka; bentonite--colloidal aqueous aluminium silicate) Concentration and crystallisation (diethyl ether/n-hexane)

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

Procedure: The 4-acetyl-pyridine N-oxide used is prepared in the following manner: 11.0 ml (100 mmol) of 4-acetyl-pyridine and 31.3 g (100 mmol) of 55% m-chloro-perbenzoic acid are boiled under RF for 16 h in 200 ml of methylene chloride. Precipitation with 200 ml of diethyl ether gives 4-acetyl-pyridine N-oxide; m.p. 132°-133°. The 4-acetyl-pyridine N-oxide used is prepared in the following manner Precipitation with 200 ml of diethyl ether