2-(dimethylaminomethylidene)-5,5-dimethylcyclohexane-1,3-dione

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

Procedure: Prepared analogously to Example 1 starting from methylhydrazine and 2-(dimethylaminomethylene)-5,5-dimethyl-cyclohexane-1,3-dione.

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

Procedure: Prepared analogously to Example 1 starting from methylhydrazine and 2-(dimethylaminomethylene)-5,5-dimethyl-cyclohexane-1,3-dione.

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

Procedure: According to Scheme 2 Step 2: At 0° C., acetic acid (8.55 mL) followed by hydrazine monohydrate (197 mmol, 11.3 mL), were added slowly to a solution of 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione (197 mmol, 38.5 g) in butanol (400 mL). The reaction mixture was stirred under reflux for 16 hours. After evaporation of the filtrate, the crude residue was purified by flash chromatography over silica gel cyclohexane/AcOEt (100:0 to 50:50) and then over C18 gel using water/MeOH (100:0 to 50:50) as eluent to yield 6,6-dimethyl-6,7-dihydro-1H-indazol-4(5H)-one (76.7 mmol, 12.6 g, 39%) as a pale yellow solid. At 0° C. under reflux for 16 hours After evaporation of the filtrate the crude residue was purified by flash chromatography over silica gel cyclohexane/AcOEt (100:0 to 50:50)

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

Procedure: According to Scheme 2 Step 1: A solution of 5,5-dimethylcyclohexane-1,3-dione (428 mmol, 60 g) and of 1,1-dimethoxy-N,N-dimethylmethanamine (514 mmol, 68.2 mL) was stirred at room temperature for 1 hour. After evaporation and trituration in cyclohexane, 38.5 g (197 mmol, 46%) of 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione were obtained as a pale yellow solid. After evaporation and trituration in cyclohexane

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

Procedure: Prepared analogously to Example 1 starting from methylhydrazine and 2-(dimethylaminomethylene)-5,5-dimethyl-cyclohexane-1,3-dione.