3-乙酰基-4-氧代戊酸乙酯

反应条件: temp:0.00; pressure:0.00; stir:

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

实验步骤: A solution of 5-aminoindazole in 50 ml. of ethanol, 100 ml. of water and 8 ml. of 12M hydrochloric acid was cooled to 0° C. and a previously cooled solution of 3.41 g. (49.5 mmoles) of sodium nitrite in 10 ml. of water was added dropwise. After 30 minutes, the dark red mixture was added to the solution of 9.2 g, (49.5 mmoles) of ethyl 3-acetyl-4-oxopentanoate in 20 ml. of ethanol and 14.2 ml. of pyridine. The resulting mixture was stirred at 0° for 30 minutes and then at room temperature for an additional 30 minutes and finally the solid collected by filtration to give 11.2 g. of solid. at room temperature for an additional 30 minutes finally the solid collected by filtration to give 11.2 g

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

实验步骤: A solution of 1.06 gm. (6.58 mmoles) of 2-(4-aminophenyl)tetrazole in 20 ml. of ethanol and 1.18 ml. of concentrated hydrochloric acid and 10 ml. of water was cooled in an ice bath and treated dropwise with a solution of 500 mg. of sodium nitrite in 10 ml. of water. After the addition of an additional 10 ml. of water, the mixture was stirred for 25 minutes at room temperature. The mixture was then added to a solution of 1.35 gm. (7.2 mmoles) of ethyl 3-acetyl-4-oxopentanoate and 2.66 ml. of pyridine in 15 ml. of ethanol. A solid began to separate. After 1 hour, 10 ml. of 1 M hydrochloric acid was added to adjust the pH to 2-3. An additional 50 ml. of water was added and the solid was collected and washed thoroughly with water and dried. 1.74 g. was obtained. treated dropwise with a solution of 500 mg After the addition of an additional 10 ml The mixture was then added to a solution of 1.35 gm to separate of 1 M hydrochloric acid was added of water was added the solid was collected washed thoroughly with water dried was obtained

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

实验步骤: To a suspension of 10 g. (58.1 mmoles) of 4-aminobenzenesulfonamide in 50 ml of 1:1 ethanol/water was added 7.3 ml. of concentrated hydrochloric acid. To the cooled mixture was added in portions 4.41 g (63.9 mmoles) of sodium nitrite in 5 ml. of water. The mixture was allowed to come to room temperature and after 15 minutes was poured into a solution of 11.9 g. (63.9 mmoles) of ethyl-3-acetyl-4-oxopentanoate in 12.2 ml. of pyridine and 25 ml. of ethanol. An orange solid began to separate which was collected after 30 minutes by filtration. After drying, 24.3 g. of material was obtained. To a suspension of 10 g was poured into a solution of 11.9 g to separate which was collected after 30 minutes by filtration After drying of material was obtained

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

实验步骤: To a suspension of 1 gm. (5.8 mmoles) of 3 -amino-4-chlorobenzoic acid in 20 ml. of ethanol was added 5 ml. of water and 1 ml. of 12 N hydrochloric acid. The resultant solution was cooled in an ice bath and to the cooled solution was added in small portions 442 mg. (6.4 mmoles) of sodium nitrite in 3 ml. of water. The mixture was allowed to warm to room temperature and after 30 minutes was added to a suspension of 1.19 gm. (6.4 mmole) of ethyl 3-acetyl-4-oxopentanoate, 1.8 gm. of sodium acetate, 20 ml. of ethanol and 5 ml. of water. The reaction mixture turned dark orange. After stirring for one hour, the mixture was acidified with 3 N hydrochloric acid and the resultant solids collected by filtration. After drying the material, 2.53 g. was obtained. To a suspension of 1 gm was added in small portions 442 mg was added to a suspension of 1.19 gm the resultant solids collected by filtration After drying the material, 2.53 g was obtained

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

实验步骤: A mixture of 3 g. (19.8 mmol) of 4-amino-3-methylbenzoic acid in 50 ml. of water and 50 ml. of ethanol and 3.56 ml. of concentrated hydrochloric acid was cooled in an ice bath and then 1.5 g. of NaNO2 (21.8 mmol.) in 10 ml. of water was added portionwise. The mixture was allowed to come to room temperature and then added to a solution of 4.06 g. (21.8 mmol.) of ethyl 3-acetyl-4-oxopentanoate and 8 ml. of pyridine in 25 ml. of ethanol. The reaction mixture was left for 24 hours at room temperature with stirring. The mixture was acidified with concentrated hydrochloric acid and diluted with 20 ml. of water. The resulting solid was collected and washed with water and pentane to yield 5.2 g. A mixture of 3 g to come to room temperature added to a solution of 4.06 g diluted with 20 ml The resulting solid was collected washed with water and pentane to yield 5.2 g

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

实验步骤: To a solution of ethyl 3-acetyl-4-oxopentanoate (synthesized as described D. P. Shrout and D. A. Lightner, Synth. Commun. 20 (1990), 2075) (9.676 g, 51.96 mmol) in ethanol, at 0° C., was added slowly a solution of hydrazine hydrate (2.990 g, 59.75 g) in absolute ethanol. The reaction mixture was warmed to room temperature and stirred for 2 hours. After removing ethanol under vacuum, dichloromethane and water were added to the crude product and the organic layer was separated. The aqueous layer was extracted further with dichloromethane and the combined organic extracts were washed with water. After drying over MgSO4 and evaporation of the solvent under reduced pressure, the pyrazole was isolated as a yellow oil. Yield: 72% (6.777 g, 37.2 mmol). After removing ethanol under vacuum, dichloromethane and water were added to the crude product the organic layer was separated The aqueous layer was extracted further with dichloromethane the combined organic extracts were washed with water After drying over MgSO4 and evaporation of the solvent under reduced pressure

反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 5-aminoindazole in 50 ml. of ethanol, 100 ml. of water and 8 ml. of 12 M hydrochloric acid was cooled to 0° C. and a previously cooled solution of 3.41 g. (49.5 mmoles) of sodium nitrite in 10 ml. of water was added dropwise. After 30 minutes, the dark red mixture was added to the solution of 9.2 g, (49.5 mmoles) of ethyl 3-acetyl-4-oxopentanoate in 20 ml. of ethanol and 14.2 ml. of pyridine. The resulting mixture was stirred at 0° C. for 30 minutes and then at room temperature for an additional 30 minutes and finally the solid collected by filtration to give 11.2 g. of solid. at room temperature for an additional 30 minutes finally the solid collected by filtration to give 11.2 g

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

实验步骤: A solution of 1.06 gm. (6.58 mmoles) of 2-(4-aminophenyl)tetrazole in 20 ml. of ethanol and 1.18 ml. of concentrated hydrochloric acid and 10 ml. of water was cooled in an ice bath and treated dropwise with a solution of 500 mg. of sodium nitrite in 10 ml. of water. After the addition of an additional 10 ml. of water, the mixture was stirred for 25 minutes at room temperature. The mixture was then added to a solution of 1.35 gm. (7.2 mmoles) of ethyl 3-acetyl-4-oxopentanoate and 2.66 ml. of pyridine in 15 ml. of ethanol. A solid began to separate. After 1 hour, 10 ml. of 1 M hydrochloric acid was added to adjust the pH to 2-3. An additional 50 ml. of water was added and the solid was collected and washed thoroughly with water and dried. 1.74 g. was obtained. treated dropwise with a solution of 500 mg After the addition of an additional 10 ml The mixture was then added to a solution of 1.35 gm to separate of 1 M hydrochloric acid was added of water was added the solid was collected washed thoroughly with water dried was obtained

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

实验步骤: To a suspension of 10 g. (58.1 mmoles) of 4-aminobenzenesulfonamide in 50 ml of 1:1 ethanol/water was added 7.3 ml. of concentrated hydrochloric acid. To the cooled mixture was added in portions 4.41. g (63.9 mmoles) of sodium nitrite in 5 ml. of water. The mixture was allowed to come to room temperature and after 15 minutes was poured into a solution of 11.9 g. (63.9 mmoles) of ethyl-3-acetyl-4-oxopentanoate in 12.2 ml. of pyridine, in 25 ml. of ethanol. An orange solid began to separate which was collected after 30 minutes by filtration. After drying, 24.3 g. of material was obtained. To a suspension of 10 g To the cooled mixture was added in portions 4.41 was poured into a solution of 11.9 g to separate which was collected after 30 minutes by filtration After drying of material was obtained

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

实验步骤: To a suspension of 1 gm. (5.8 mmoles) of 3-amino-4-chlorobenzoic acid in 20 ml. of ethanol was added 5 ml. of water and 1 ml. of 12 N hydrochloric acid. The resultant solution was cooled in an ice bath and to the cooled solution was added in small portions 442 mg. (6.4 mmoles) of sodium nitrite in 3 ml. of water. The mixture was allowed to warm to room temperature and after 30 minutes was added to a suspension of 1.19 gm. (6.4 mmole) of ethyl 3-acetyl-4-oxopentanoate, 1.8 gm. of sodium acetate, 20 ml. of ethanol and 5 ml. of water. The reaction mixture turned dark orange. After stirring for one hour, the mixture was acidified with 3 N hydrochloric acid and the resultant solids collected by filtration. After drying the material, 2.53 g. was obtained. To a suspension of 1 gm was added in small portions 442 mg was added to a suspension of 1.19 gm the resultant solids collected by filtration After drying the material, 2.53 g was obtained

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

实验步骤: To a suspension of 1 gm. (5.8 mmoles) of 3-amino-4-chlorobenzoic acid in 20 ml. of ethanol was added 5 ml. of water and 1 ml. of 12 N hydrochloric acid. The resultant solution was cooled in an ice bath and to the cooled solution was added in small portions 442 mg. (6.4 mmoles) of sodium nitrite in 3 ml. of water. The mixture was allowed to warm to room temperature and after 30 minutes was added to a suspension of 1.19 gm. (6.4 mmole) of ethyl 3-acetyl-4-oxopentanoate, 1.8 gm. of sodium acetate, 20 ml. of ethanol and 5 ml. of water. The reaction mixture turned dark orange. After stirring for one hour, the mixture was acidified with 3 N hydrochloric acid and the resultant solids collected by filtration. After drying the material, 2.53 g. was obtained. To a suspension of 1 gm was added in small portions 442 mg was added to a suspension of 1.19 gm the resultant solids collected by filtration After drying the material, 2.53 g was obtained