3-甲基-2-氧代丁酰乙酯

反应条件: temp:0.00; pressure:0.00; stir:

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: 146 mg (0.435 mmol) of the compound from example 43A were initially charged in ethanol (8 ml), then 69 mg (0.48 mmol) of ethyl 3-methyl-2-oxobutanoate were added and the reaction mixture was heated to reflux overnight. Thereafter, a catalytic amount of conc. sulfuric acid was added and the mixture was again heated to reflux overnight. Subsequently, the mixture was cooled to RT, and the solid formed was filtered off, washed with methanol and dried under high vacuum. This gave 26 mg (14% of theory) of the title compound in solid form. the reaction mixture was heated to reflux overnight the mixture was again heated to reflux overnight the solid formed was filtered off washed with methanol dried under high vacuum

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

实验步骤: 146 mg (0.435 mmol) of the compound from example 43A were initially charged in ethanol (8 ml), then 69 mg (0.48 mmol) of ethyl 3-methyl-2-oxobutanoate were added and the reaction mixture was heated to reflux overnight. Thereafter, a catalytic amount of conc. sulfuric acid was added and the mixture was again heated to reflux overnight. Subsequently, the mixture was cooled to RT, and the solid formed was filtered off, washed with methanol and dried under high vacuum. This gave 26 mg (14% of theory) of the title compound in solid form. the reaction mixture was heated to reflux overnight the mixture was again heated to reflux overnight the solid formed was filtered off washed with methanol dried under high vacuum

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

实验步骤: To a solution of 3-Methyl-2-oxo-butyric acid ethyl ester (1c) (1.88 g, 13.04 mmol) in 45 mL of CHCl3, butyl-hydrazine oxalate salt (2.11 g, 11.85 mmol) was added followed by NaOAc (1.94 g, 23.4 mmol) and MgSO4 (1.43 g, 11.88 mmol). The mixture was heated to reflux for 3.5 hours under N2 atmosphere with stirring. After cooling, the solid was filtered off and the filtrate was concentrated under reduced vacuum. The residue was first cleaned by an extraction between EtOAc (50 mL×3) and H2O (20 mL). The organic layer was concentrated under reduced pressure and dried under high vacuum overnight to give 2.17 g of the crude product (3b) in 85.4% yield as a mixture of the E- and Z-isomers. This crude product was directly used in the next step without further purification. LC-MS (ESI+): m/e=215.4 [M+1]+, 237.1 [M+Na]+ (exact ms: 214.17). The mixture was heated to reflux for 3.5 hours under N2 atmosphere After cooling the solid was filtered off the filtrate was concentrated under reduced vacuum The residue was first cleaned by an extraction between EtOAc (50 mL×3) and H2O (20 mL) The organic layer was concentrated under reduced pressure dried under high vacuum overnight

反应条件: temp:0.00; pressure:0.00; stir:

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: To a solution of 3-Methyl-2-oxo-butyric acid ethyl ester (1c) (1.88 g, 13.04 mmol) in 45 mL of CHCl3, butyl-hydrazine oxalate salt (2.11 g, 11.85 mmol) was added followed by NaOAc (1.94 g, 23.4 mmol) and MgSO4 (1.43 g, 11.88 mmol). The mixture was heated to reflux for 3.5 hours under N2 atmosphere with stirring. After cooling, the solid was filtered off and the filtrate was concentrated under reduced vacuum. The residue was first cleaned by an extraction between EtOAc (50 mL×3) and H2O (20 mL). The organic layer was concentrated under reduced pressure and dried under high vacuum overnight to give 2.17 g of the crude product (3b) in 85.4% yield as a mixture of the E- and Z-isomers. This crude product was directly used in the next step without further purification. LC-MS (ESI+): m/e=215.4 [M+1]+, 237.1 [M+Na]+ (exact ms: 214.17). The mixture was heated to reflux for 3.5 hours under N2 atmosphere After cooling the solid was filtered off the filtrate was concentrated under reduced vacuum The residue was first cleaned by an extraction between EtOAc (50 mL×3) and H2O (20 mL) The organic layer was concentrated under reduced pressure dried under high vacuum overnight

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

实验步骤: 1.014 g (7.035 mmol) of ethyl 3-methyl-2-oxobutanoate in 15 ml of ethanol were initially introduced and heated to reflux. Then, 2.000 g (7.035 mmol) of 1-(2-fluorobenzyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carboximidohydrazide suspended in 20 ml of ethanol were added and the mixture was heated under reflux overnight. After cooling, the mixture was filtered off with suction, and the filtercake was washed with a little ethanol and dried under high vacuum. This gave 918 mg of the target compound (36% of theory). heated to reflux were added the mixture was heated under reflux overnight After cooling the mixture was filtered off with suction the filtercake was washed with a little ethanol dried under high vacuum

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

实验步骤: A mixture of ethyl 2-oxo-3-methylbutanoate (23.76 g) and phenylhydrazine (25 ml) was heated at 60° C. in toluene for about one hour, during which time a slight vacuum was used in order to remove the water. After removing the solvent, the residue was chromatographed on silica gel, using a 4/1 petroleum ether/ethyl acetate mixture as eluent, in order to give the desired product in the form of a yellow oil. to remove the water After removing the solvent the residue was chromatographed on silica gel

反应条件: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Isopropylmagnesium chloride (2.0M in ether, 200 mmol) was added to a solution of diethyl oxalate (29.23 g, 20.0 mmol) in dry diethyl ether (100 ml) at −70° C. over a period of one hour. The mixture was stirred at −70° C. for a further half an hour and then poured immediately into a vigorously stirred suspension of ice (80 g), diethyl ether (100 ml) and concentrated HCl (18 ml). The aqueous phase was separated out and the organic phase washed with water (100 ml) and then dried (MgSO4) and the solvent was removed in order to leave the desired product in the form of a colourless oil. The aqueous phase was separated out the organic phase washed with water (100 ml) dried (MgSO4) the solvent was removed in order

反应条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of (o-fluorobenzyl)magnesium bromide in diethyl ether (100 mL), prepared from the corresponding o-fluorobenzyl bromide (9.45 g, 50.0 mmol) and magnesium turnings (1.32 g, 55.0 mmol), was added to a solution of ethyl 3-methyl-2-oxobutanoate (7.2 g, 50 mmol) in diethyl ether (50 mL) cooled at −78° C. After 30 min at −78° C., the reaction mixture was warmed to 0° C. and poured into saturated aqueous NH4Cl. The organic layer was washed with brine, dried and concentrated. The residue was dissolved in methanol (200 mL) and kept with 2 N KOH (75 mL) for 2 hrs. at 50° C. The reaction mixture was diluted with water and washed with hexane. The aqueous layer was acidified with 2 N HCl, saturated with sodium chloride and extracted with ethyl acetate. Removal of solvents gave the title compound. the reaction mixture was warmed to 0° C. The organic layer was washed with brine dried concentrated The residue was dissolved in methanol (200 mL) kept with 2 N KOH (75 mL) for 2 hrs at 50° C The reaction mixture was diluted with water washed with hexane extracted with ethyl acetate Removal of solvents