ethyl 1-hydroxycyclopropane-1-carboxylate

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

Procedure: 20 mg of t-butyl 4-[7-(2-butynyl)-2-chloro-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate and 20 mg of ethyl 1-hydroxycyclopropanecarboxylate were dissolved in 0.2 ml of N-methylpyrrolidone, and 10 mg of sodium hydride was added thereto. The mixture was stirred at room temperature overnight. 1N hydrochloric acid was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was concentrated to give 63 mg of t-butyl 4-[7-(2-butynyl)-2-(1-ethoxycarbonylcyclopropyloxy)-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate. This compound was dissolved in a solution consisting of 0.4 ml of ethanol and 0.1 ml of a 5N aqueous sodium hydroxide solution, and the mixture was stirred at 50° C. overnight. 1N hydrochloric acid solution was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was concentrated to give 22 mg of t-butyl 4-[7-(2-butynyl)-2-(1-carboxycyclopropyloxy)-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate. 11 mg of this compound was dissolved in trifluoroacetic acid, and the mixture was concentrated. The residue was purified by reverse-phase high performance liquid chromatography (using an acetonitrile-water mobile phase (containing 0.1% trifluoroacetic acid)) to give 1.64 mg of the title compound. the mixture was extracted with ethyl acetate The organic layer was concentrated

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

Procedure: 20 mg of t-butyl 4-[7-(2-butynyl)-2-chloro-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate and 20 mg of ethyl 1-hydroxycyclopropanecarboxylate were dissolved in 0.2 ml of N-methylpyrrolidone, and 10 mg of sodium hydride was added thereto. The mixture was stirred at room temperature overnight. 1N hydrochloric acid was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was concentrated to give 63 mg of t-butyl 4-[7-(2-butynyl)-2-(1-ethoxycarbonylcyclopropyloxy)-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate. This compound was dissolved in a solution consisting of 0.4 ml of ethanol and 0.1 ml of a 5N aqueous sodium hydroxide solution, and the mixture was stirred at 50° C. overnight. 1N hydrochloric acid solution was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was concentrated to give 22 mg of t-butyl 4-[7-(2-butynyl)-2-(1-carboxycyclopropyloxy)-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate. 11 mg of this compound was dissolved in trifluoroacetic acid, and the mixture was concentrated. The residue was purified by reverse-phase high performance liquid chromatography (using an acetonitrile-water mobile phase (containing 0.1% trifluoroacetic acid)) to give 1.64 mg of the title compound. the mixture was extracted with ethyl acetate The organic layer was concentrated

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

Procedure: Sodium hydride (60%, 166 mg, 4.15 mmol) was added to a solution of ethyl 1-hydroxycyclopropanecarboxylate (0.41 mL, 3.59 mmol) in THF (10 mL) at room temperature. After 15 min, 3 drops of 15-crown-5 were added followed by 4-bromo-1-fluoro-2-nitrobenzene (0.42 mL, 3.41 mmol). Mixture was stirred at room temperature for 24 hours. After diluting with 50 mL of ethyl acetate, mixture was quenched by addition of brine (25 mL) and layers were separated. Aqueous phase was extracted with ethyl acetate and combined organics were dried (MgSO4), filtered, and concentrated under reduced pressure. Resulting residue was purified via silica gel column chromatography (0-30% ethyl acetate/hexanes) to yield ethyl 1-(4-bromo-2-nitrophenoxy)cyclopropanecarboxylate 7.20 (750 mg) was quenched by addition of brine (25 mL) and layers were separated Aqueous phase was extracted with ethyl acetate combined organics were dried (MgSO4) filtered concentrated under reduced pressure Resulting residue was purified via silica gel column chromatography (0-30% ethyl acetate/hexanes)

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

Procedure: Sodium hydride (60%, 166 mg, 4.15 mmol) was added to a solution of ethyl 1-hydroxycyclopropanecarboxylate (0.41 mL, 3.59 mmol) in THF (10 mL) at room temperature. After 15 min, 3 drops of 15-crown-5 were added followed by 4-bromo-1-fluoro-2-nitrobenzene (0.42 mL, 3.41 mmol). Mixture was stirred at room temperature for 24 hours. After diluting with 50 mL of ethyl acetate, mixture was quenched by addition of brine (25 mL) and layers were separated. Aqueous phase was extracted with ethyl acetate and combined organics were dried (MgSO4), filtered, and concentrated under reduced pressure. Resulting residue was purified via silica gel column chromatography (0-30% ethyl acetate/hexanes) to yield ethyl 1-(4-bromo-2-nitrophenoxy)cyclopropanecarboxylate 7.20 (750 mg) was quenched by addition of brine (25 mL) and layers were separated Aqueous phase was extracted with ethyl acetate combined organics were dried (MgSO4) filtered concentrated under reduced pressure Resulting residue was purified via silica gel column chromatography (0-30% ethyl acetate/hexanes)

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

Procedure: Sodium hydride (60%, 166 mg, 4.15 mmol) was added to a solution of ethyl 1-hydroxycyclopropanecarboxylate (0.41 mL, 3.59 mmol) in THF (10 mL) at room temperature. After 15 min, 3 drops of 15-crown-5 were added followed by 4-bromo-1-fluoro-2-nitrobenzene (0.42 mL, 3.41 mmol). Mixture was stirred at room temperature for 24 hours. After diluting with 50 mL of ethyl acetate, mixture was quenched by addition of brine (25 mL) and layers were separated. Aqueous phase was extracted with ethyl acetate and combined organics were dried (MgSO4), filtered, and concentrated under reduced pressure. Resulting residue was purified via silica gel column chromatography (0-30% ethyl acetate/hexanes) to yield ethyl 1-(4-bromo-2-nitrophenoxy)cyclopropanecarboxylate 7.20 (750 mg) was quenched by addition of brine (25 mL) and layers were separated Aqueous phase was extracted with ethyl acetate combined organics were dried (MgSO4) filtered concentrated under reduced pressure Resulting residue was purified via silica gel column chromatography (0-30% ethyl acetate/hexanes)

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

Procedure: Step 81) A THF solution (50 mL) of 1-hydroxy-cyclopropanecarboxylic acid ethyl ester (5 g, 38.4 mmol) and pyridine (3.3 mL, 41 mmol) was added dropwise a phosgen/toleune solution (25 mL, 47.5 mmol) at 0° C. in 5-10 min. the reaction mixture was allowed slowly warm up overnite. The solid was filtered off and the filtration was concentrated in vacuo. The residue was dissolved in hexane, refiltered, and concentrated in vacuo to afford.7.4 g (100%) the product. The product was dissolved in CH2Cl2 (100 mL) as a stack solution: 1H NMR (300 MHz, CHLOROFORM-D) □ ppm 1.25 (t, J=7.14 Hz, 3H), 1.37 (m, 2H), 1.57 (m, 2H), 4.21 (q, J=6.95 Hz, 2H); (ppm) 13.97, 15.75, 62.07, 62.13, 150.54, 168.71. was allowed slowly warm up overnite The solid was filtered off the filtration was concentrated in vacuo The residue was dissolved in hexane concentrated in vacuo to afford

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

Procedure: To a stirred solution of ethyl-1-hydroxycyclopropane carboxylate (2.93 g, 20.5 mmol) in THF (50 mL) was added sodium hydride (60% in mineral oil, 981 mg, 24.5 mmol) under argon atmosphere. After 10 min, 15-crown-5 (0.2 mL) followed by 4-bromo-2-nitro-fluorophenol (4.5 g, 20.5 mmol) were added. The reaction mixture was stirred at room temperature overnight then quenched by the addition of methanol (1.5 mL) and diluted with ethyl acetate. The mixture was washed with brine, and the organic layer was dried over anhydrous sodium sulfate, concentrated and purified by silica gel column chromatography to give 1-(4-bromo-2-nitro-phenoxy)-cyclopropanecarboxylic acid ethyl ester (3.51 g). were added then quenched by the addition of methanol (1.5 mL) diluted with ethyl acetate The mixture was washed with brine the organic layer was dried over anhydrous sodium sulfate concentrated purified by silica gel column chromatography

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

Procedure: To a stirred solution of ethyl-1-hydroxycyclopropane carboxylate (2.93 g, 20.5 mmol) in THF (50 mL) was added sodium hydride (60% in mineral oil, 981 mg, 24.5 mmol) under argon atmosphere. After 10 min, 15-crown-5 (0.2 mL) followed by 4-bromo-2-nitro-fluorphenol (4.5 g, 20.5 mmol) were added. The reaction mixture was stirred at room temperature overnight then quenched by the addition of methanol (1.5 mL) and diluted with ethyl acetate. The mixture was washed with brine, and the organic layer was dried over anhydrous sodium sulfate, concentrated and purified by silica gel column chromatography to give 1-(4-bromo-2-nitro-phenoxy)-cyclopropanecarboxylic acid ethyl ester (3.51 g). were added then quenched by the addition of methanol (1.5 mL) diluted with ethyl acetate The mixture was washed with brine the organic layer was dried over anhydrous sodium sulfate concentrated purified by silica gel column chromatography

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

Procedure: To a solution of ethyl 1-hydroxycyclopropanecarboxylate (1040 mg, 8.000 mmol) and PTSA (137 mg, 0.800 mmol) in DCM (20 mL) was added a solution of DHP (1344 mg, 16.00 mmol) in DCM (10 mL) dropwise at 0° C. The mixture was stirred for 20 h at room temperature. After concentration, the residue was purified by silica gel column chromatography eluting with petroleum ether/ethyl acetate (10/1) to afford the title compound (1500 mg, 85%) as oil. LC-MS (ESI): m/z=215 (M+H)+. After concentration the residue was purified by silica gel column chromatography eluting with petroleum ether/ethyl acetate (10/1)

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

Procedure: To a stirred solution of ethyl-1-hydroxycyclopropane carboxylate (2.93 g, 20.5 mmol) in THF (50 mL) was added sodium hydride (60% in mineral oil, 981 mg, 24.5 mmol) under argon atmosphere. After 10 min, 15-crown-5 (0.2 mL) followed by 4-bromo-2-nitro-fluorophenol (4.5 g, 20.5 mmol) were added. The reaction mixture was stirred at room temperature overnight then quenched by the addition of methanol (1.5 mL) and diluted with ethyl acetate. The mixture was washed with brine, and the organic layer was dried over anhydrous sodium sulfate, concentrated and purified by silica gel column chromatography to give 1-(4-bromo-2-nitro-phenoxy)-cyclopropanecarboxylic acid ethyl ester (3.51 g). were added then quenched by the addition of methanol (1.5 mL) diluted with ethyl acetate The mixture was washed with brine the organic layer was dried over anhydrous sodium sulfate concentrated purified by silica gel column chromatography

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

Procedure: 20 mg of t-butyl 4-[7-(2-butynyl)-2-chloro-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate and 20 mg of ethyl 1-hydroxycyclopropanecarboxylate were dissolved in 0.2 ml of N-methylpyrrolidone, and 10 mg of sodium hydride was added thereto. The mixture was stirred at room temperature overnight. 1N hydrochloric acid was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was concentrated to give 63 mg of t-butyl 4-[7-(2-butynyl)-2-(1-ethoxycarbonylcyclopropyloxy)-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate. This compound was dissolved in a solution consisting of 0.4 ml of ethanol and 0.1 ml of a 5N aqueous sodium hydroxide solution, and the mixture was stirred at 50° C. overnight. 1N hydrochloric acid solution was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was concentrated to give 22 mg of t-butyl 4-[7-(2-butynyl)-2-(1-carboxycyclopropyloxy)-1-methyl-6-oxo-6,7-dihydro-1H-purin-8-yl]piperazine-1-carboxylate. 11 mg of this compound was dissolved in trifluoroacetic acid, and the mixture was concentrated. The residue was purified by reverse-phase high performance liquid chromatography (using an acetonitrile-water mobile phase (containing 0.1% trifluoroacetic acid)) to give 1.64 mg of the title compound. the mixture was extracted with ethyl acetate The organic layer was concentrated