2-chloro-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:; See reaction.notes.procedure_details.

Procedure: A solution of 2-methyl-2-trifluoromethyl-6-phenylsulfonyl-3,4-dihydro-2H-1,4-benzoxazine (200 mg) and 2-chloropyridine N-oxide.HCl (121 mg;) in dimethylsulfoxide (8 mL) was treated with sodium hydride (60% dispersion in oil, 58 mg), and stirred under a nitrogen atmosphere for 18 hours. The mixture was then poured into a solution containing aqueous sodium hydroxide (0.5N, 150 mL) and saturated sodium chloride (20 mL.) and extracted with ethyl acetate. (3×150 mL). The combined organic portions were washed with aqueous sodium hydroxide (0.5N, 30 mL) and saturated sodium chloride (5 mL) and evaporated to yield a black semi-solid. Chromatography of this solid on silica gel eluting with ethyl acetate then ethyl acetate/methanol (97:3) yielded the title compound (110 mg) as a white solid; mp 192°-193° C.; NMR (250 MHz, d6-DMSO): 1.55 (s,3), 3.98 (dd,2), 6.81 (s,1), 7.20 (d,1), 7.40 (dd,1), 7.45 (m,2), 7.62 (m,4) 7.85 (dd,2), 8.42 (d,1); MS: m/z=451(M+1). Analysis for C21H17F3N2O4S: Calculated: C, 56.00; H, 3.78; N, 6.22; Found: C, 56.10; H, 3.88; N, 6.02. The mixture was then poured into a solution extracted with ethyl acetate The combined organic portions were washed with aqueous sodium hydroxide (0.5N, 30 mL) and saturated sodium chloride (5 mL) evaporated to yield a black semi-solid

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

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

Procedure: 2-Chloro-pyridine-1-oxide (10 g) is cooled in an ice bath and treated with concentrated H2SO4 (15 ml), followed by the dropwise addition of a mixture of concentrated H2SO4 (15 ml) and fuming HNO3 (27 ml, s.g. 1.5) over a 70 minute period. The acidic solution is heated in a steam bath for 2.5 hours, then allowed to reach room temperature and poured onto ice water (600 ml), stirring being continued until all the ice has melted. The resultant solid is filtered off and dissolved in hot chloroform, the solution being dried and the solvent evaporated in vacuo to give a yellow solid. The aqueous filtrate obtained after the removal of the original solid is neutralised with saturated aqueous Na2CO3 and extracted continuously with chloroform, the extract being dried and evaporated in vacuo to yield a yellow solid. The two yellow solids are combined and recrystallised from ethanol to give 2-chloro-4-nitro-pyridine-1-oxide as yellow crystals (7.46 g, 56%). The acidic solution is heated in a steam bath for 2.5 hours to reach room temperature poured onto ice water (600 ml) The resultant solid is filtered off dissolved in hot chloroform the solution being dried the solvent evaporated in vacuo to give a yellow solid The aqueous filtrate obtained after the removal of the original solid extracted continuously with chloroform the extract being dried evaporated in vacuo to yield a yellow solid recrystallised from ethanol

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

Procedure: 2-Chloro-pyridine-1-oxide (10 g) is cooled in an ice bath and treated with concentrated H2SO4 (15 ml), followed by the dropwise addition of a mixture of concentrated H2SO4 (15 ml) and fuming HNO3 (27 ml, s.g. 1.5) over a 70 minute period. The acidic solution is heated in a steam bath for 2.5 hours, then allowed to reach room temperature and poured onto ice water (600 ml), stirring being continued until all the ice has melted. The resultant solid is filtered off and dissolved in hot chloroform, the solution being dried and the solvent evaporated in vacuo to give a yellow solid. The aqueous filtrate obtained after the removal of the original solid is neutralised with saturated aqueous Na2CO3 and extracted continuously with chloroform, the extract being dried and evaporated in vacuo to yield a yellow solid. The two yellow solids are combined and recrystallised from ethanol to give 2-chloro-4-nitro-pyridine-1-oxide as yellow crystals (7.46 g, 56%). The acidic solution is heated in a steam bath for 2.5 hours to reach room temperature poured onto ice water (600 ml) The resultant solid is filtered off dissolved in hot chloroform the solution being dried the solvent evaporated in vacuo to give a yellow solid The aqueous filtrate obtained after the removal of the original solid extracted continuously with chloroform the extract being dried evaporated in vacuo to yield a yellow solid recrystallised from ethanol

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

Procedure: A mixture of 2-chloropyridine-N-oxide (1 6.6 g, 0.1 mole), 3-amino-1-propanol (15.3 mL, 0.2 mole), NaHCO3 (42 g, 0.5 mole), and tert-amyl alcohol (100 mL) was heated to reflux. After 21 hr, the reaction was cooled, diluted with CH2Cl2 (300 mnL), and suction filtered to remove insoluble materials. The filtrate was concentrated and reconcentrated from toluene to leave a yellow oil. Silica gel chromatography (20% MeOH/CHCl3) gave the title compound (15.62 g, 93%) as a yellow solid: TLC (20% MeOH/CHCl3) Rf 0.48; 1H NMR (250, CDCl3) δ 8.07 (dd, J=6.6, 1.2 Hz, 1 H), 7.34 (br t, 1 H), 7.10-7.30 (m, 1 H), 6.64 (dd, J=8.5, 1.4 Hz, 1 H), 6.40-6.60 (m, 1 H), 4.49 (br s, 1 H), 3.65-3.90 (m, 2 H), 3.35-3.60 (m, 2 H), 1.75-2.00 (m, 2 H); MS (ES) m/e 169 (M+H)+. was heated to reflux the reaction was cooled filtered to remove insoluble materials The filtrate was concentrated to leave a yellow oil

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

Procedure: A mixture of 2-chloropyridine-N-oxide (1 6.6 g, 0.1 mole), 3-amino-1-propanol (15.3 mL, 0.2 mole), NaHCO3 (42 g, 0.5 mole), and tert-amyl alcohol (100 mL) was heated to reflux. After 21 hr, the reaction was cooled, diluted with CH2Cl2 (300 mnL), and suction filtered to remove insoluble materials. The filtrate was concentrated and reconcentrated from toluene to leave a yellow oil. Silica gel chromatography (20% MeOH/CHCl3) gave the title compound (15.62 g, 93%) as a yellow solid: TLC (20% MeOH/CHCl3) Rf 0.48; 1H NMR (250, CDCl3) δ 8.07 (dd, J=6.6, 1.2 Hz, 1 H), 7.34 (br t, 1 H), 7.10-7.30 (m, 1 H), 6.64 (dd, J=8.5, 1.4 Hz, 1 H), 6.40-6.60 (m, 1 H), 4.49 (br s, 1 H), 3.65-3.90 (m, 2 H), 3.35-3.60 (m, 2 H), 1.75-2.00 (m, 2 H); MS (ES) m/e 169 (M+H)+. was heated to reflux the reaction was cooled filtered to remove insoluble materials The filtrate was concentrated to leave a yellow oil

Conditions: temp:67.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-chloropyridine-N-oxide (16.6 g, 100 mmoles), 3-amino-1-propanol (15.3 ml, 200 mmoles), NaHCO3 (42 g, 0.5 mole), and tert-amyl alcohol (100 ml) was heated to reflux. After 23 hours, the reaction was cooled, diluted with CH2Cl2 (300 ml), and filtered to remove insoluble materials. The filtrate was concentrated to afford a brown oil. The oil was dried under vacuum overnight. Ether (100 ml) was added to give a brown solid. The ether was decanted and the solid was washed further with ether/acetonitrile (3/1). The resulting solid was heated at 67° C. under vacuum to give the desired product (13.5 g). 1H NMR was consistent with the proposed structure. was heated to reflux the reaction was cooled filtered to remove insoluble materials The filtrate was concentrated to afford a brown oil The oil was dried under vacuum overnight Ether (100 ml) was added to give a brown solid The ether was decanted the solid was washed further with ether/acetonitrile (3/1)

Conditions: temp:67.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2-chloropyridine-N-oxide (16.6 g, 100 mmoles), 3-amino-1-propanol (15.3 ml, 200 mmoles), NaHCO3 (42 g, 0.5 mole), and tert-amyl alcohol (100 ml) was heated to reflux. After 23 hours, the reaction was cooled, diluted with CH2Cl2 (300 ml), and filtered to remove insoluble materials. The filtrate was concentrated to afford a brown oil. The oil was dried under vacuum overnight. Ether (100 ml) was added to give a brown solid. The ether was decanted and the solid was washed further with ether/acetonitrile (3/1). The resulting solid was heated at 67° C. under vacuum to give the desired product (13.5 g). 1H NMR was consistent with the proposed structure. was heated to reflux the reaction was cooled filtered to remove insoluble materials The filtrate was concentrated to afford a brown oil The oil was dried under vacuum overnight Ether (100 ml) was added to give a brown solid The ether was decanted the solid was washed further with ether/acetonitrile (3/1)