tert-butyl 1-hydroxycyclopropane-1-carboxylate

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Under ice cooling, to a toluene suspension (60 ml) of 63% sodium hydride (2.81 g) was added dropwise a toluene solution (30 ml) of tert-butyl 1-hydroxycyclopropanecarboxylate (11.65 g) over 15 minutes, followed by stirring as it stood for 30 minutes, and further at room temperature for 2 hours. After cooling again using an ice bath, a toluene solution (30 ml) of 2,5-dichloro-3-nitropyridine (7.13 g) was added, and the temperature was brought back to room temperature, followed by stirring for 3 hours. After a 10% aqueous citric acid solution was added, the separated organic layer was washed with saturated sodium chloride solution, and the aqueous layer was extracted with ethyl acetate. The collected organic layer was dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford tert-butyl 1-[(5-chloro-3-nitropyridin-2-yl)oxy]cyclopropanecarboxylate (9.61 g). further at room temperature for 2 hours After cooling again was brought back to room temperature by stirring for 3 hours the separated organic layer was washed with saturated sodium chloride solution the aqueous layer was extracted with ethyl acetate The collected organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Under ice cooling, to a toluene suspension (60 ml) of 63% sodium hydride (2.81 g) was added dropwise a toluene solution (30 ml) of tert-butyl 1-hydroxycyclopropanecarboxylate (11.65 g) over 15 minutes, followed by stirring as it stood for 30 minutes, and further at room temperature for 2 hours. After cooling again using an ice bath, a toluene solution (30 ml) of 2,5-dichloro-3-nitropyridine (7.13 g) was added, and the temperature was brought back to room temperature, followed by stirring for 3 hours. After a 10% aqueous citric acid solution was added, the separated organic layer was washed with saturated sodium chloride solution, and the aqueous layer was extracted with ethyl acetate. The collected organic layer was dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford tert-butyl 1-[(5-chloro-3-nitropyridin-2-yl)oxy]cyclopropanecarboxylate (9.61 g). further at room temperature for 2 hours After cooling again was brought back to room temperature by stirring for 3 hours the separated organic layer was washed with saturated sodium chloride solution the aqueous layer was extracted with ethyl acetate The collected organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: At room temperature under shielded light, to N,N′-diisopropylcarbodiimide (99.75 g) was added copper(I) chloride (1.57 g), and then tert-butanol (83 ml) was added dropwise over 20 minutes, followed by stirring for 4 days. The supernatant (48 ml) was added dropwise to a dichloromethane suspension (120 ml) of 1-hydroxycyclopropanecarboxylic acid (17.12 g) using an ice bath over 15 minutes. The temperature was brought back to room temperature, followed by stirring for 40 hours, and then acetic acid (11.5 ml) was added and stirred for 1 hour. The reaction suspension was filtered, and ice water and sodium hydrogen carbonate were added to the filtrate for neutralization. After the precipitate was filtered off, the organic layer separated from the filtrate was washed with saturated sodium hydrogen carbonate, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. After pentane was added to the residue, insolubles were filtered off, and the filtrate was concentrated under reduced pressure to afford tert-butyl 1-hydroxycyclopropanecarboxylate (11.65 g). over 15 minutes was brought back to room temperature by stirring for 40 hours stirred for 1 hour The reaction suspension was filtered ice water and sodium hydrogen carbonate were added to the filtrate for neutralization After the precipitate was filtered off the organic layer separated from the filtrate was washed with saturated sodium hydrogen carbonate dried over anhydrous sodium sulfate concentrated under reduced pressure After pentane was added to the residue, insolubles were filtered off the filtrate was concentrated under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Under ice cooling, to a toluene suspension (60 ml) of 63% sodium hydride (2.81 g) was added dropwise a toluene solution (30 ml) of tert-butyl 1-hydroxycyclopropanecarboxylate (11.65 g) over 15 minutes, followed by stirring as it stood for 30 minutes, and further at room temperature for 2 hours. After cooling again using an ice bath, a toluene solution (30 ml) of 2,5-dichloro-3-nitropyridine (7.13 g) was added, and the temperature was brought back to room temperature, followed by stirring for 3 hours. After a 10% aqueous citric acid solution was added, the separated organic layer was washed with saturated sodium chloride solution, and the aqueous layer was extracted with ethyl acetate. The collected organic layer was dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford tert-butyl 1-[(5-chloro-3-nitropyridin-2-yl)oxy]cyclopropanecarboxylate (9.61 g). further at room temperature for 2 hours After cooling again was brought back to room temperature by stirring for 3 hours the separated organic layer was washed with saturated sodium chloride solution the aqueous layer was extracted with ethyl acetate The collected organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: At room temperature under shielded light, to N,N′-diisopropylcarbodiimide (99.75 g) was added copper(I) chloride (1.57 g), and then tert-butanol (83 ml) was added dropwise over 20 minutes, followed by stirring for 4 days. The supernatant (48 ml) was added dropwise to a dichloromethane suspension (120 ml) of 1-hydroxycyclopropanecarboxylic acid (17.12 g) using an ice bath over 15 minutes. The temperature was brought back to room temperature, followed by stirring for 40 hours, and then acetic acid (11.5 ml) was added and stirred for 1 hour. The reaction suspension was filtered, and ice water and sodium hydrogen carbonate were added to the filtrate for neutralization. After the precipitate was filtered off, the organic layer separated from the filtrate was washed with saturated sodium hydrogen carbonate, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. After pentane was added to the residue, insolubles were filtered off, and the filtrate was concentrated under reduced pressure to afford tert-butyl 1-hydroxycyclopropanecarboxylate (11.65 g). over 15 minutes was brought back to room temperature by stirring for 40 hours stirred for 1 hour The reaction suspension was filtered ice water and sodium hydrogen carbonate were added to the filtrate for neutralization After the precipitate was filtered off the organic layer separated from the filtrate was washed with saturated sodium hydrogen carbonate dried over anhydrous sodium sulfate concentrated under reduced pressure After pentane was added to the residue, insolubles were filtered off the filtrate was concentrated under reduced pressure