methyl 3-oxopropanoate

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

Procedure: A solution of the respective 3-oxo-propionic acid methyl ester derivative (4.8 mmol, 1.0 eq.) in glacial acetic acid (1.9 mL) was cooled to 10° C. and at this temperature was added a solution of NaNO2 (5.6 mmol, 1.16 eq.) in water (0.68 mL). After the addition was complete (15 min), the solution was allowed to warm to room temperature and stirred for 2 h. Then the solution was poured into water (10 mL) and after a few minutes crystals begun to appear. This suspension was cooled in an ice-bath and crystals were collected by filtration. The cake was washed several times with cold water and the water was removed by the azeotrope of toluene-water in vacuo to give 2-hydroxyimino-3-oxo-propionic acid methyl ester derivatives which were dissolved in a mixture of acetic anhydride (1.375 mL) and glacial acetic acid (1.8 mL). To this solution was added sodium acetate (0.296 mmol, 0.06 eq.) and HgCl2 (0.01 mmol, 0.002 eq.). The mixture was refluxed for 1 h, then cooled to room temperature and filtered. The solid was rinsed with ether, the organic filtrate was recovered, washed 3 times with water and one time with 1M aq. K2CO3. The organic layer was dried over MgSO4, filtered and concentrated. The crude products were purified by flash chromatography to afford the corresponding 2-acetylamino-3-oxo-propionic acid methyl ester derivatives. After the addition (15 min) This suspension was cooled in an ice-bath crystals were collected by filtration The cake was washed several times with cold water the water was removed by the azeotrope of toluene-water in vacuo

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

Procedure: A solution of the respective 3-oxo-propionic acid methyl ester derivative (4.8 mmol, 1.0 eq.) in glacial acetic acid (1.9 mL) was cooled to 10° C. and at this temperature was added a solution of NaNO2 (5.6 mmol, 1.16 eq.) in water (0.68 mL). After the addition was complete (15 min), the solution was allowed to warm to room temperature and stirred for 2 h. Then the solution was poured into water (10 mL) and after a few minutes crystals begun to appear. This suspension was cooled in an ice-bath and crystals were collected by filtration. The cake was washed several times with cold water and the water was removed by the azeotrope of toluene-water in vacuo to give 2-hydroxyimino-3-oxo-propionic acid methyl ester derivatives which were dissolved in a mixture of acetic anhydride (1.375 mL) and glacial acetic acid (1.8 mL). To this solution was added sodium acetate (0.296 mmol, 0.06 eq.) and HgCl2 (0.01 mmol, 0.002 eq.). The mixture was refluxed for 1 h, then cooled to room temperature and filtered. The solid was rinsed with ether, the organic filtrate was recovered, washed 3 times with water and one time with 1M aq. K2CO3. The organic layer was dried over MgSO4, filtered and concentrated. The crude products were purified by flash chromatography to afford the corresponding 2-acetylamino-3-oxo-propionic acid methyl ester derivatives. After the addition (15 min) This suspension was cooled in an ice-bath crystals were collected by filtration The cake was washed several times with cold water the water was removed by the azeotrope of toluene-water in vacuo

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

Procedure: A solution of the respective 3-oxo-propionic acid methyl ester derivative (4.8 mmol, 1.0 eq.) in glacial acetic acid (1.9 mL) was cooled to 10° C. and at this temperature was added a solution of NaNO2 (5.6 mmol, 1.16 eq.) in water (0.68 mL). After the addition was complete (15 min), the solution was allowed to warm to rt and stirred for 2 h. Then the solution was poured into water (10 mL) and after a few minutes crystals begun to appear. This suspension was cooled in an ice-bath and crystals were collected by filtration. The cake was washed several times with cold water and the water was removed by the azeotrope of toluene-water in vacuo to give 2-hydroxyimino-3-oxo-propionic acid methyl ester derivatives which were dissolved in a mixture of acetic anhydride (1.4 mL) and glacial acetic acid (1.8 mL). To this solution was added sodium acetate (0.296 mmol, 0.06 eq.) and HgCl2 (0.01 mmol, 0.002 eq.). The mixture was refluxed for 1 h, then cooled to rt and filtered. The solid was rinsed with ether, the organic filtrate was recovered, washed 3 times with water and one time with 1M aq. K2CO3. The organic layer was dried over MgSO4, filtered and concentrated. The crude products were purified by flash chromatography to afford the corresponding 2-acetylamino-3-oxo-propionic acid methyl ester derivatives. After the addition (15 min) This suspension was cooled in an ice-bath crystals were collected by filtration The cake was washed several times with cold water the water was removed by the azeotrope of toluene-water in vacuo

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

Procedure: A solution of the respective 3-oxo-propionic acid methyl ester derivative (4.8 mmol, 1.0 eq.) in glacial acetic acid (1.9 mL) was cooled to 10° C. and at this temperature was added a solution of NaNO2 (5.6 mmol, 1.16 eq.) in water (0.68 mL). After the addition was complete (15 min), the solution was allowed to warm to room temperature and stirred for 2 h. Then the solution was poured into water (10 mL) and after a few minutes crystals begun to appear. This suspension was cooled in an ice-bath and crystals were collected by filtration. The cake was washed several times with cold water and the water was removed by the azeotrope of toluene-water in vacuo to give 2-hydroxyimino-3-oxo-propionic acid methyl ester derivatives which were dissolved in a mixture of acetic anhydride (1.375 mL) and glacial acetic acid (1.8 mL). To this solution was added sodium acetate (0.296 mmol, 0.06 eq.) and HgCl2 (0.01 mmol, 0.002 eq.). The mixture was refluxed for 1 h, then cooled to room temperature and filtered. The solid was rinsed with ether, the organic filtrate was recovered, washed 3 times with water and one time with 1M aq. K2CO3. The organic layer was dried over MgSO4, filtered and concentrated. The crude products were purified by flash chromatography to afford the corresponding 2-acetylamino-3-oxo-propionic acid methyl ester derivatives. After the addition (15 min) This suspension was cooled in an ice-bath crystals were collected by filtration The cake was washed several times with cold water the water was removed by the azeotrope of toluene-water in vacuo

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

Procedure: A solution of the respective 3-oxo-propionic acid methyl ester derivative (4.8 mmol, 1.0 eq.) in glacial acetic acid (1.9 mL) was cooled to 10° C. and at this temperature was added a solution of NaNO2 (5.6 mmol, 1.16 eq.) in water (0.68 mL). After the addition was complete (15 min), the solution was allowed to warm to room temperature and stirred for 2 h. Then the solution was poured into water (10 mL) and after a few minutes crystals begun to appear. This suspension was cooled in an ice-bath and crystals were collected by filtration. The cake was washed several times with cold water and the water was removed by the azeotrope of toluene-water in vacuo to give 2-hydroxyimino-3-oxo-propionic acid methyl ester derivatives which were dissolved in a mixture of acetic anhydride (1.375 mL) and glacial acetic acid (1.8 mL). To this solution was added sodium acetate (0.296 mmol, 0.06 eq.) and HgCl2 (0.01 mmol, 0.002 eq.). The mixture was refluxed for 1 h, then cooled to room temperature and filtered. The solid was rinsed with ether, the organic filtrate was recovered, washed 3 times with water and one time with 1M aq. K2CO3. The organic layer was dried over MgSO4, filtered and concentrated. The crude products were purified by flash chromatography to afford the corresponding 2-acetylamino-3-oxo-propionic acid methyl ester derivatives. After the addition (15 min) This suspension was cooled in an ice-bath crystals were collected by filtration The cake was washed several times with cold water the water was removed by the azeotrope of toluene-water in vacuo

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

Procedure: A solution of the respective 3-oxo-propionic acid methyl ester derivative (4.8 mmol, 1.0 eq.) in glacial acetic acid (1.9 mL) was cooled to 10° C. and at this temperature was added a solution of NaNO2 (5.6 mmol, 1.16 eq.) in water (0.68 mL). After the addition was complete (15 min), the solution was allowed to warm to rt and stirred for 2 h. Then the solution was poured into water (10 mL) and after a few minutes crystals begun to appear. This suspension was cooled in an ice-bath and crystals were collected by filtration. The cake was washed several times with cold water and the water was removed by the azeotrope of toluene-water in vacuo to give 2-hydroxyimino-3-oxo-propionic acid methyl ester derivatives which were dissolved in a mixture of acetic anhydride (1.4 mL) and glacial acetic acid (1.8 mL). To this solution was added sodium acetate (0.296 mmol, 0.06 eq.) and HgCl2 (0.01 mmol, 0.002 eq.). The mixture was refluxed for 1 h, then cooled to rt and filtered. The solid was rinsed with ether, the organic filtrate was recovered, washed 3 times with water and one time with 1M aq. K2CO3. The organic layer was dried over MgSO4, filtered and concentrated. The crude products were purified by flash chromatography to afford the corresponding 2-acetylamino-3-oxo-propionic acid methyl ester derivatives. After the addition (15 min) This suspension was cooled in an ice-bath crystals were collected by filtration The cake was washed several times with cold water the water was removed by the azeotrope of toluene-water in vacuo