4-甲基-4-硝基戊醛

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: 4-Methyl-4-nitropentanal is prepared by condensation of acrolein and 2-nitropropane according to a known procedure (Synthesis 1986, 237). To a solution of 4-methyl-4-nitropentanal (8.5 g, 58.56 mmol) in acetic acid (125 ml) is added bromine (9.12 g, 57.07 mmol) dropwise while the temperature is kept below 15° C. After stirring for 15 minutes at room temperature the reaction is poured into a mixture of water and ice (250 ml) and extracted two times with dichloromethane. The combined organic extracts are washed with water and with brine, successively, dried over magnesium sulfate, and the solvent is removed under reduced pressure to leave 10.7 g of 2-bromo-4-methyl-4-nitropentanal which is used for the next step without further purification. is kept below 15° C extracted two times with dichloromethane The combined organic extracts are washed with water and with brine successively, dried over magnesium sulfate the solvent is removed under reduced pressure

反应条件: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Water (70 ml) was added to hydantoin (20.8 g, 210 mmol) and sodium carbonate (7.2 g, 70 mmol) and the mixture was dissolved by heating to 85° C. 4-Methyl-4-nitropentanal (20.0 g, 140 mmol) was dissolved in isopropyl alcohol (130 ml) and added. The mixture was refluxed under heating for 2 h and isopropyl alcohol was evaporated under reduced pressure. Water (20 ml) and concentrated hydrochloric acid were added to adjust its pH to 8. The precipitated crystals were separated and dried to give 5-(1-hydroxy-4-methyl-4-nitropentylidene)hydantoin (27.3 g). This compound (19.4 g, 78.9 mmol) was dissolved in pyridine (60 ml) and methanesulfonyl chloride (7.9 ml, 102.6 mmol) was added under ice-cooling. The mixture was stirred at room temperature for 3 h. Water (50 ml) was added and the mixture was extracted three times with ethyl acetate (50 ml). The extract solutions were combined and washed 4 times with 1 mol hydrochloric acid (50 ml). After separation of layers, the organic layer was concentrated to dryness to give 5-(1-methanesulfonyloxy-4-methyl-4-nitropentylidene)hydantoin (20.5 g). To this compound (5.74 g, 17.8 mmol) were added tetrahydrofuran (80 ml) and 1,8-diazabicyclo[5.4.0]undec-7-ene (2.7 ml, 17.8 mmol) and the mixture was stirred at room temperature for 4 h. Tetrahydrofuran was concentrated under reduced pressure and the residue was extracted with ethyl acetate (50 ml) and 0.5 M hydrochloric acid (80 ml). After separation of layers, ethyl acetate was concentrated to dryness to give 5-(4-methyl-4-nitropentylidene)hydantoin (4.0 g, 17.6 mmol, yield 61.6%). the mixture was dissolved added The mixture was refluxed under heating for 2 h isopropyl alcohol was evaporated under reduced pressure Water (20 ml) and concentrated hydrochloric acid were added The precipitated crystals were separated dried

反应条件: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Water (70 ml) was added to hydantoin (20.8 g, 210 mmol) and sodium carbonate (7.2 g, 70 mmol) and the mixture was dissolved by heating to 85° C. 4-Methyl-4-nitropentanal (20.0 g, 140 mmol) was dissolved in isopropyl alcohol (130 ml) and added. The mixture was refluxed under heating for 2 h and isopropyl alcohol was evaporated under reduced pressure. Water (20 ml) and concentrated hydrochloric acid were added to adjust its pH to 8. The precipitated crystals were separated and dried to give 5-(1-hydroxy-4-methyl-4-nitropentylidene)hydantoin (27.3 g). This compound (19.4 g, 78.9 mmol) was dissolved in pyridine (60 ml) and methanesulfonyl chloride (7.9 ml, 102.6 mmol) was added under ice-cooling. The mixture was stirred at room temperature for 3 h. Water (50 ml) was added and the mixture was extracted three times with ethyl acetate (50 ml). The extract solutions were combined and washed 4 times with 1 mol hydrochloric acid (50 ml). After separation of layers, the organic layer was concentrated to dryness to give 5-(1-methanesulfonyloxy-4-methyl-4-nitropentylidene)hydantoin (20.5 g). To this compound (5.74 g, 17.8 mmol) were added tetrahydrofuran (80 ml) and 1,8-diazabicyclo[5.4.0]undec-7-ene (2.7 ml, 17.8 mmol) and the mixture was stirred at room temperature for 4 h. Tetrahydrofuran was concentrated under reduced pressure and the residue was extracted with ethyl acetate (50 ml) and 0.5 M hydrochloric acid (80 ml). After separation of layers, ethyl acetate was concentrated to dryness to give 5-(4-methyl-4-nitropentylidene)hydantoin (4.0 g, 17.6 mmol, yield 61.6%). the mixture was dissolved added The mixture was refluxed under heating for 2 h isopropyl alcohol was evaporated under reduced pressure Water (20 ml) and concentrated hydrochloric acid were added The precipitated crystals were separated dried

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

实验步骤: Oily 4-methyl-4-nitropentanal (4.0 g, 28 mmol), hydantoin (4.0 g, 40 mmol) and sodium carbonate (2.8 g, 20 mmol) were added to 50% aqueous acetonitrile (200 ml) and the mixture was refluxed with stirring for 3 days. The reaction mixture was concentrated and extracted three times with ethyl acetate. The organic layer was concentrated to dryness to give 5-(4-methyl-4-nitropentylidene)hydantoin (3.15 g, 13.9 mmol, yield 50.0%). the mixture was refluxed The reaction mixture was concentrated extracted three times with ethyl acetate The organic layer was concentrated to dryness

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

实验步骤: 4-Methyl-4-nitrovaleronitrile (10.4 g, 13 mmol) was dissolved in methylene chloride (100 ml) and 1M diisobutyl aluminum hydride-hexane solution (100 ml) was added dropwise at −50° C. The mixture was stirred for 0.5 h, and water (8 ml) was added gradually, after which magnesium sulfate (5.0 g) was added. The mixture was filtrated and 1N hydrochloric acid (50 ml) was added. The mixture was stirred for 0.5 h and the layers were separated. The organic layer was washed with saturated brine and the solvent was evaporated. The residue was dried to give oily 4-methyl-4-nitropentanal (6.9 g, 48 mmol). The mixture was filtrated 1N hydrochloric acid (50 ml) was added The mixture was stirred for 0.5 h the layers were separated The organic layer was washed with saturated brine the solvent was evaporated The residue was dried

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

实验步骤: 4-Methyl-4-nitrovaleronitrile (10.4 g, 13 mmol) was dissolved in methylene chloride (100 ml) and 1M diisobutyl aluminum hydride-hexane solution (100 ml) was added dropwise at −50° C. The mixture was stirred for 0.5 h, and water (8 ml) was added gradually, after which magnesium sulfate (5.0 g) was added. The mixture was filtrated and 1N hydrochloric acid (50 ml) was added. The mixture was stirred for 0.5 h and the layers were separated. The organic layer was washed with saturated brine and the solvent was evaporated. The residue was dried to give oily 4-methyl-4-nitropentanal (6.9 g, 48 mmol). The mixture was filtrated 1N hydrochloric acid (50 ml) was added The mixture was stirred for 0.5 h the layers were separated The organic layer was washed with saturated brine the solvent was evaporated The residue was dried

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

实验步骤: Then, 4-methyl-4-nitropentanal and hydantoin are reacted to give 5-(4-methyl-4-nitropentylidene)hydantoin (see JP-A-11-140076).

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

实验步骤: 4-Methyl-4-nitropentanal is prepared by condensation of acrolein and 2-nitropropane according to a known procedure (Synthesis 1986, 237). To a solution of 4-methyl-4-nitropentanal (8.5 g, 58.56 mmol) in acetic acid (125 ml) is added bromine (9.12 g, 57.07 mmol) dropwise while the temperature is kept below 15° C. After stirring for 15 minutes at room temperature the reaction is poured into a mixture of water and ice (250 ml) and extracted two times with dichloromethane. The combined organic extracts are washed with water and with brine, successively, dried over magnesium sulfate, and the solvent is removed under reduced pressure to leave 10.7 g of 2-bromo-4-methyl-4-nitropentanal which is used for the next step without further purification. is kept below 15° C extracted two times with dichloromethane The combined organic extracts are washed with water and with brine successively, dried over magnesium sulfate the solvent is removed under reduced pressure

反应条件: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Water (70 ml) was added to hydantoin (20.8 g, 210 mmol) and sodium carbonate (7.2 g, 70 mmol) and the mixture was dissolved by heating to 85° C. 4-Methyl-4-nitropentanal (20.0 g, 140 mmol) was dissolved in isopropyl alcohol (130 ml) and added. The mixture was refluxed under heating for 2 h and isopropyl alcohol was evaporated under reduced pressure. Water (20 ml) and concentrated hydrochloric acid were added to adjust its pH to 8. The precipitated crystals were separated and dried to give 5-(1-hydroxy-4-methyl-4-nitropentylidene)hydantoin (27.3 g). This compound (19.4 g, 78.9 mmol) was dissolved in pyridine (60 ml) and methanesulfonyl chloride (7.9 ml, 102.6 mmol) was added under ice-cooling. The mixture was stirred at room temperature for 3 h. Water (50 ml) was added and the mixture was extracted three times with ethyl acetate (50 ml). The extract solutions were combined and washed 4 times with 1 mol hydrochloric acid (50 ml). After separation of layers, the organic layer was concentrated to dryness to give 5-(1-methanesulfonyloxy-4-methyl-4-nitropentylidene)hydantoin (20.5 g). To this compound (5.74 g, 17.8 mmol) were added tetrahydrofuran (80 ml) and 1,8-diazabicyclo[5.4.0]undec-7-ene (2.7 ml, 17.8 mmol) and the mixture was stirred at room temperature for 4 h. Tetrahydrofuran was concentrated under reduced pressure and the residue was extracted with ethyl acetate (50 ml) and 0.5 M hydrochloric acid (80 ml). After separation of layers, ethyl acetate was concentrated to dryness to give 5-(4-methyl-4-nitropentylidene)hydantoin (4.0 g, 17.6 mmol, yield 61.6%). the mixture was dissolved added The mixture was refluxed under heating for 2 h isopropyl alcohol was evaporated under reduced pressure Water (20 ml) and concentrated hydrochloric acid were added The precipitated crystals were separated dried

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

实验步骤: Oily 4-methyl-4-nitropentanal (4.0 g, 28 mmol), hydantoin (4.0 g, 40 mmol) and sodium carbonate (2.8 g, 20 mmol) were added to 50% aqueous acetonitrile (200 ml) and the mixture was refluxed with stirring for 3 days. The reaction mixture was concentrated and extracted three times with ethyl acetate. The organic layer was concentrated to dryness to give 5-(4-methyl-4-nitropentylidene)hydantoin (3.15 g, 13.9 mmol, yield 50.0%). the mixture was refluxed The reaction mixture was concentrated extracted three times with ethyl acetate The organic layer was concentrated to dryness