2-ACETYL-1,3-CYCLOHEXANEDIONE

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

Procedure: A 200-mL 2-necked round bottom flask was fitted with thermometer, reflux condenser, magnetic stirrer, and nitrogen bypass. The flask was charged with 4.53 g (25 mmol) of 4-nitrophenyl acetate, 2.94 g (26.25 mmol) of 1,3-cyclohexanedione, 5.69 g (56.25 mmol) of triethylamine, 0.22 g (2.5 mmol) of acetone cyanohydrin, and 60 mL of acetonitrile. The mixture was heated to reflux with stirring for 3 hr. The mixture was allowed to cool to room temperature and volatiles were removed under reduced pressure to give 20.0 g of red oil. Chromatographic separation on silica gel afforded the title product. 1H NMR (CDCl3): δ 1.99 (m, 2), 2.52 (m, 2), 2.62 (s, 3), 2.68 (m, 2). A 200-mL 2-necked round bottom flask was fitted with thermometer reflux condenser, magnetic stirrer The mixture was heated to reflux volatiles were removed under reduced pressure

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

Procedure: A solution of 11 ml of methylhydrazine in 50 ml of methanol was added dropwise to an ice-cold solution of 30 grams of 2-acetyl-1,3-cyclohexanedione in 200 ml of methanol and the reaction mixture was heated at reflux for 90 minutes. The solvent was removed under reduced pressure and the residue was triturated in hexane and cooled to give a clammy tan solid. This crude product was recrystallized from a mixture of toluene and hexane to give 1,5,6,7-tetrahydro-1,3-dimethyl-4H-indazol-4-one as a yellow crystalline solid melting at about 82.5°-84° C. the reaction mixture was heated at reflux for 90 minutes The solvent was removed under reduced pressure the residue was triturated in hexane cooled to give a clammy tan solid This crude product was recrystallized from a mixture of toluene and hexane

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

Procedure: To an ice-cold solution of 33.3 grams of 2-acetyl-1,3-cyclohexanedione in 400 ml of methanol was added dropwise a solution of 7.2 ml of hydrazine in 50 ml of methanol and the resulting reaction mixture was heated at reflux for 20 hours. The solvent was then removed under reduced pressure and the residue was triturated in ethyl ether to give 1,5,6,7-tetrahydro-3-methyl-4H-indazol-4-one as a yellow crystalline solid melting at about 154°-157° C. the resulting reaction mixture was heated at reflux for 20 hours The solvent was then removed under reduced pressure the residue was triturated in ethyl ether

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

Procedure: A solution of 11 ml of methylhydrazine in 50 ml of methanol was added dropwise to an ice-cold solution of 30 grams of 2-acetyl-1,3-cyclohexanedione in 200 ml of methanol and the reaction mixture was heated at reflux for 90 minutes. The solvent was removed under reduced pressure and the residue was triturated in hexane and cooled to give a clammy tan solid. This crude product was recrystallized from a mixture of toluene and hexane to give 1,5,6,7-tetrahydro-1,3-dimethyl-4H-indazol-4-one as a yellow crystalline solid melting at about 82.5°-84° C. the reaction mixture was heated at reflux for 90 minutes The solvent was removed under reduced pressure the residue was triturated in hexane cooled to give a clammy tan solid This crude product was recrystallized from a mixture of toluene and hexane

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

Procedure: To an ice-cold solution of 33.3 grams of 2-acetyl1,3-cyclohexanedione in 400 ml of methanol was added dropwise a solution of 7.2 ml of hydrazine in 50 ml of methanol and the resulting reaction mixture was heated at reflux for 20 hours. The solvent was then removed under reduced pressure and the residue was triturated in ethyl ether to give 1,5,6,7-tetrahydro-3-methyl-4H-indazol-4-one as a yellow crystalline solid melting at about 154°-157° C. the resulting reaction mixture was heated at reflux for 20 hours The solvent was then removed under reduced pressure the residue was triturated in ethyl ether

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

Procedure: To an ice-cold solution of 33.3 grams of 2-acetyl1,3-cyclohexanedione in 400 ml of methanol was added dropwise a solution of 7.2 ml of hydrazine in 50 ml of methanol and the resulting reaction mixture was heated at reflux for 20 hours. The solvent was then removed under reduced pressure and the residue was triturated in ethyl ether to give 1,5,6,7-tetrahydro-3-methyl-4H-indazol-4-one as a yellow crystalline solid melting at about 154°-157° C. the resulting reaction mixture was heated at reflux for 20 hours The solvent was then removed under reduced pressure the residue was triturated in ethyl ether

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

Procedure: A 200-mL 2-necked round bottom flask was fitted with thermometer, reflux condenser, magnetic stirrer, and nitrogen bypass. The flask was charged with 4.53 g (25 mmol) of 4-nitrophenyl acetate, 2.94 g (26.25 mmol) of 1,3-cyclohexanedione, 5.69 g (56.25 mmol) of triethylamine, 0.22 g (2.5 mmol) of acetone cyanohydrin, and 60 mL of acetonitrile. The mixture was heated to reflux with stirring for 3 hr. The mixture was allowed to cool to room temperature and volatiles were removed under reduced pressure to give 20.0 g of red oil. Chromatographic separation on silica gel afforded the title product. 1H NMR (CDCl3): δ 1.99 (m, 2), 2.52 (m, 2), 2.62 (s, 3), 2.68 (m, 2). A 200-mL 2-necked round bottom flask was fitted with thermometer reflux condenser, magnetic stirrer The mixture was heated to reflux volatiles were removed under reduced pressure

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

Procedure: A 200-mL 2-necked round bottom flask was fitted with thermometer, reflux condenser, magnetic stirrer, and nitrogen bypass. The flask was charged with 4.53 g (25 mmol) of 4-nitrophenyl acetate, 2.94 g (26.25 mmol) of 1,3-cyclohexanedione, 5.69 g (56.25 mmol) of triethylamine, 0.22 g (2.5 mmol) of acetone cyanohydrin, and 60 mL of acetonitrile. The mixture was heated to reflux with stirring for 3 hr. The mixture was allowed to cool to room temperature and volatiles were removed under reduced pressure to give 20.0 g of red oil. Chromatographic separation on silica gel afforded the title product. 1H NMR (CDCl3): δ 1.99 (m, 2), 2.52 (m, 2), 2.62 (s, 3), 2.68 (m, 2). A 200-mL 2-necked round bottom flask was fitted with thermometer reflux condenser, magnetic stirrer The mixture was heated to reflux volatiles were removed under reduced pressure

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

Procedure: Prepared analogously to Example 1 starting from 2-acetyl-cyclohexane-1,3-dione and ethylhydrazine.

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

Procedure: Prepared analogously to Example 1 starting from 2-acetyl-cyclohexane-1,3-dione and ethylhydrazine.

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

Procedure: According to Scheme 4 Step 2: AlCl3 (26.5 mmol, 3.53 g) was added to a solution of 3-oxocyclohex-1-enyl acetate (13.2 mmol, 2.04 g) in dichloroethane (10 mL) and the reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was poured onto a solution of H2SO4 in ice. The aqueous phase was extracted with CHCl3 (50 mL). The organic phase was washed with water, dried over Na2SO4, was filtered and was concentrated to yield 2-acetylcyclohexane-1,3-dione (7.78 mmol, 1.20 g, 59%) as a yellow oil. The aqueous phase was extracted with CHCl3 (50 mL) The organic phase was washed with water dried over Na2SO4 was filtered was concentrated

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

Procedure: According to Scheme 4 Step 3: Hydrazine monohydrate (7.59 mmol, 0.37 mL) was added to a solution of 2-acetylcyclohexane-1,3-dione (7.59 mmol, 1.17 g) in EtOH (19 mL) at 0° C. and the reaction mixture was stirred at room temperature for 2 hours. After evaporation, the crude residue was purified by flash chromatography over silica gel using DCM/AcOEt (70:30 to 50:50) as eluent to yield 3-methyl-6,7-dihydro-1H-indazol-4(5H)-one (1.76 mmol, 265 mg, 23%) as a yellow solid. After evaporation the crude residue was purified by flash chromatography over silica gel