ethyl 4-hydroxyiminocyclohexane-1-carboxylate

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

Procedure: Ethyl 4-(hydroxyimino)cyclohexanecarboxylate was reacted in the presence of conc. sulfuric acid in ethanol to produce ethyl 7-oxoazepane-4-carboxylate.

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of ethyl 4-(hydroxyimino)cyclohexanecarboxylate (1.85 g) in pyridine (10 mL) was added 4-methylbenzenesulfonyl chloride (2.28 g) over 5-10 min at −20° C. The reaction mixture was stirred for several hours while allowing to gradually warm to 0° C. The reaction mixture was added to ice water, and the precipitate was collected by filtration, and washed with ice water to give the title compound (2.54 g). the precipitate was collected by filtration washed with ice water

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

Procedure: To a solution of hydroxyamine hydrochloride (15.3 g) and sodium acetate (24.1 g) in water (60 mL) was added ethyl 4-oxocyclohexanecarboxylate (25.0 g) over 20 min. The reaction mixture was stirred at room temperature overnight, and extracted with tert-butyl methyl ether. The extract was washed with saturated brine, and dried over magnesium sulfate to give the title compound (27.2 g). extracted with tert-butyl methyl ether The extract was washed with saturated brine dried over magnesium sulfate

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

Procedure: To a solution of 2,4,6-trichloro-1,3,5-triazine (21.7 g) in DMF (25 mL) was added dropwise ethyl 4-(hydroxyimino)cyclohexanecarboxylate (27.2 g) in DMF (220 mL) over 30 min. The mixture was stirred at room temperature overnight, poured into water, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give ethyl 7-oxoazepane-4-carboxylate (2.40 g). the mixture was extracted with ethyl acetate The extract was washed with saturated brine dried over anhydrous magnesium sulfate the solvent was evaporated under reduced pressure The residue was purified by silica gel column chromatography (ethyl acetate/hexane)

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

Procedure: To a solution of hydroxyamine hydrochloride (15.3 g) and sodium acetate (24.1 g) in water (58.8 mL) was added dropwise ethyl 4-oxocyclohexanecarboxylate (25.0 g) over 20 min. The reaction mixture was stirred at room temperature overnight, and extracted with tert-butyl methyl ether. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give the title compound (27.2 g). extracted with tert-butyl methyl ether The extract was washed with saturated brine dried over anhydrous magnesium sulfate the solvent was evaporated under reduced pressure