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With phthalic anhydride; urea-hydrogen peroxide; In water; ethyl acetate; at 45℃; |
tert-Butyl-3-(3-methylpyridin-2-yl)benzoate (1.0 eq) is dissolved in EtOAc (6 vol). Water (0. 3 vol) is added followed by urea-hydrogen peroxide (3 eq). The phthalic anhydride (3 eq) is added portion-wise as a solid to maintain the temperature in the reactor below 45 0C. After completion of phthalic anhydride addition, the mixture is heated to 45 0C. After stirring for an additional 4 hours, the heat is turned off. 10% w/w aqueous Na2Stheta3 (1.5 eq) is added via addition funnel. After completion of Na2Stheta3 addition, the mixture is stirred for an additional 30 minutes and the layers separated. The organic layer is stirred and 10% w/w aq. Na2Ctheta3 (2 eq) is added. After stirring for 30 minutes, the layers are allowed to separate. The organic phase is washed 13% w/v aq NaCl. The organic phase is then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3- methylpyridine- 1 -oxide (95%) that is used directly in the next step. |
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With phthalic anhydride; urea hydrogen peroxide adduct; In water; ethyl acetate; at 45℃; for 4h; |
Preparation of 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide tert-Butyl-3-(3-methylpyridin-2-yl)benzoate (1.0 eq) was dissolved in EtOAc (6 vol). Water (0.3 vol) was added, followed by urea-hydrogen peroxide (3 eq). Phthalic anhydride (3 eq) was then added portionwise to the mixture as a solid at a rate to maintain the temperature in the reactor below 45 C. After completion of the phthalic anhydride addition, the mixture was heated to 45 C. After stirring for an additional 4 hours, the heat was turned off. 10% w/w aqueous Na2SO3 (1.5 eq) was added via addition funnel. After completion of Na2SO3 addition, the mixture was stirred for an additional 30 min and the layers separated. The organic layer was stirred and 10% wt/wt aqueous. Na2CO3 (2 eq) was added. After stirring for 30 minutes, the layers were allowed to separate. The organic phase was washed 13% w/v aq NaCl. The organic phase was then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide (95%) that was used directly in the next step. |
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With phthalic anhydride; water; urea hydrogen peroxide adduct; In ethyl acetate; |
tert-Butyl-3-(3-methylpyridin-2-yl)benzoate (1 .0 eq) was dissolved in EtOAc (6 vol).Water (0. 3 vol) was added, followed by urea-hydrogen peroxide (3 eq). Phthalic anhydride (3eq) was then added portionwise to the mixture as a solid at a rate to maintain the temperature inthe reactor below 45 "C. After completion of the phthalic anhydride addition, the mixture washeated to 45 oc After stirring for an additional 4 hours, the heat was turned off. 10% w/waqueous Na2S03 (1.5 eq) was added via addition funnel. After completion ofNa2S03 addition,the mixture was stirred for an additional 30 min and the layers separated. The organic layer wasstirred and 10% vtlwt aqueous. Na2C03 (2 eq) was added. After stirring for 30 minutes, thelayers were allowed to separate. The organic phase was washed 13% w/v aq NaCl. The organicphase was then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide (95%) that was used directly in the next step. |
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With phthalic anhydride; urea hydrogen peroxide adduct; In water; ethyl acetate; at 45℃; |
[00301] tert-Butyl-3-(3-methylpyridin-2-yl)benzoate (1.0 eq) was dissolved in EtOAc (6 vol).Water (0. 3 vol) was added, followed by urea-hydrogen peroxide (3 eq). Phthalic anhydride (3eq) was then added portionwise to the mixture as a solid at a rate to maintain the temperature inthe reactor below 45 C. After completion of the phthalic anhydride addition, the mixture washeated to 45 C. After stirring for an additional 4 hours, the heat was turned off. 10% w/waqueous Na2S03 (1.5 eq) was added via addition funnel. After completion ofNa2S03 addition,the mixture was stirred for an additional30 min and the layers separated. The organic layer wasstirred and 10% wt/wt aqueous. Na2C03 (2 eq) was added. After stirring for 30 minutes, thelayers were allowed to separate. The organic phase was washed 13% w/v aq NaCl. The organicphase was then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide (95%) that was used directly in the next step. |
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With phthalic anhydride; urea hydrogen peroxide adduct; In water; ethyl acetate; at 45℃; |
[00316] fer -Butyl-3-(3-methylpyridin-2-yl)benzoate (1.0 eq) was dissolved in EtOAc (6 vol). Water (0. 3 vol) was added, followed by urea-hydrogen peroxide (3 eq). Phthalic anhydride (3 eq) was then added portionwise to the mixture as a solid at a rate to maintain the temperature in the reactor below 45 C. After completion of the phthalic anhydride addition, the mixture was heated to 45 C. After stirring for an additional 4 hours, the heat was turned off. 10% w/w aqueous Na2S03 (1.5 eq) was added via addition funnel. After completion of Na2S03 addition, the mixture was stirred for an additional 30 min and the layers separated. The organic layer was stirred and 10% wt/wt aqueous. Na2C03 (2 eq) was added. After stirring for 30 minutes, the layers were allowed to separate. The organic phase was washed 13% w/v aq NaCl. The organic phase was then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3- methylpyridine-1 -oxide (95%) that was used directly in the next step. |
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With phthalic anhydride; urea hydrogen peroxide adduct; In water; ethyl acetate; at 45℃; for 4h; |
Tert-butyl-3-(3-methylpyridin-2-yl)benzoate (1.0 eq) was dissolved in EtOAc (6 vol). Water (0.3 vol) was added, followed by urea-hydrogen peroxide (3 eq). Phthalic anhydride (3 eq) was then added portionwise to the mixture as a solid at a rate to maintain the temperature in the reactor below 45 C. After completion of the phthalic anhydride addition, the mixture was heated to 45 C. After stirring for an additional 4 hours, the heat was turned off. 10% w/w aqueous Na2SO3 (1.5 eq) was added via addition funnel. After completion of Na2SO3 addition, the mixture was stirred for an additional 30 min and the layers separated. The organic layer was stirred and 10% wt/wt aqueous. Na2CO3 (2 eq) was added. After stirring for 30 minutes, the layers were allowed to separate. The organic phase was washed 13% w/v aq NaCl. The organic phase was then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide (95%) that was used directly in the next step. |
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With phthalic anhydride; urea hydrogen peroxide adduct; In water; ethyl acetate; at 45℃; for 4h; |
Preparation of 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide tert-Butyl-3-(3-methylpyridin-2-yl)benzoate (1.0 eq) was dissolved in EtOAc (6 vol). Water (0.3 vol) was added, followed by urea-hydrogen peroxide (3 eq). Phthalic anhydride (3 eq) was then added portionwise to the mixture as a solid at a rate to maintain the temperature in the reactor below 45 C. After completion of the phthalic anhydride addition, the mixture was heated to 45 C. After stirring for an additional 4 hours, the heat was turned off. 10% w/w aqueous Na2SO3 (1.5 eq) was added via addition funnel. After completion of Na2SO3 addition, the mixture was stirred for an additional 30 min and the layers separated. The organic layer was stirred and 10% wt/wt aqueous. Na2CO3 (2 eq) was added. After stirring for 30 minutes, the layers were allowed to separate. The organic phase was washed 13% w/v aq NaCl. The organic phase was then filtered and concentrated to afford crude 2-(3-(tert-butoxycarbonyl)phenyl)-3-methylpyridine-1-oxide (95%) that was used directly in the next step. |
13 g |
With phthalic anhydride; urea hydrogen peroxide; In water; ethyl acetate; at 45℃; for 4h; |
13 g of tert-butyl-3(3-methylpyridin-2-yl)benzoate was dissolved in 80 ml ethyl acetate, then 4 ml water and 15 g ureahydrogen peroxide were added. 22 g of phthalic anhydride was added portion wise and the reaction temperature was maintained below 45 C. Thereaction mixture was heated to 45 C and stined for 4 hours. After completion of reaction, the reaction mass was cooled to room temperature. 100 ml of 10% sodium sulphite solution was added slowly and the reaction mixture was stined for 30 minutes. The layers were separated and organic layer was washed with 100 ml 10% sodium carbonate and 100 ml 10% sodium chloride solution. The organic phase is then filteredand concentrated under vacuum to afford 2-(3-(tert-butoxycarbonyl)phenyl)-3- methylpyridine-1-oxide (13 g, 94.8 %). |