ethyl 2-oxo-2-(2-oxocyclohexyl)acetate

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of sodium (1.75 g) in ethanol (100 ml) was treated with a mixture of diethyl oxalate (9.41 ml) and cyclohexanone (7.18 ml). The mixture was heated to 60° C. for 5 hours then cooled and then evaporated to yield oxo-(2-oxo-cyclohexyl)-acetic acid ethyl ester as a brown foam (16.635 g). LC-MS (METHOD B): RT=3.10 minutes; 197 (M−H)−. (b) 5-Methyl-2,4-dioxo-hexanoic acid ethyl ester then cooled evaporated

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

Procedure: A solution of oxo-(2-oxo-cyclohexyl)-acetic acid ethyl ester [7.5 g, Reference Example 19(a)] in acetic acid (150 ml) was treated dropwise with hydrazine monohydrate (1.65 ml). The mixture was refluxed for 8 hours, then cooled and then evaporated. The residue was partitioned between ethyl acetate (200 ml) and saturated sodium bicarbonate solution (200 ml) and the organic layer was dried over sodium sulfate and then evaporated. The residual orange oil was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and hexane (1:1, v/v) to give 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid ethyl ester (606 mg) as an orange oil which solidified on standing. LC-MS (METHOD B): RT=2.79 minutes; 195 (M+H)+. (b) 5-Isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester The mixture was refluxed for 8 hours cooled evaporated The residue was partitioned between ethyl acetate (200 ml) and saturated sodium bicarbonate solution (200 ml) the organic layer was dried over sodium sulfate evaporated The residual orange oil was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and hexane (1:1, v/v)

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of sodium (1.75 g) in ethanol (100 ml) was treated with a mixture of diethyl oxalate (9.41 ml) and cyclohexanone (7.18 ml). The mixture was heated to 60° C. for 5 hours then cooled and then evaporated to yield oxo-(2-oxo-cyclohexyl)-acetic acid ethyl ester as a brown foam (16.635 g). LC-MS (METHOD B): RT 3.10 minutes; 197 (M−H)−. then cooled evaporated

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

Procedure: A solution of oxo-(2-oxo-cyclohexyl)-acetic acid ethyl ester [7.5 g, Reference Example 19(a)] in acetic acid (150 ml) was treated dropwise with hydrazine monohydrate (1.65 ml). The mixture was refluxed for 8 hours, then cooled and then evaporated. The residue was partitioned between ethyl acetate (200 ml) and saturated sodium bicarbonate solution (200 ml) and the organic layer was dried over sodium sulfate and then evaporated. The residual orange oil was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and hexane (1:1, v/v) to give 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid ethyl ester (606 mg) as an orange oil which solidified on standing. LC-MS (METHOD B): RT=2.79 minutes; 195 (M+H)+. The mixture was refluxed for 8 hours cooled evaporated The residue was partitioned between ethyl acetate (200 ml) and saturated sodium bicarbonate solution (200 ml) the organic layer was dried over sodium sulfate evaporated The residual orange oil was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and hexane (1:1, v/v)