3-propan-2-yl-4,5-dihydro-1H-pyridazin-6-one

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,5-Dihydro-6-isopropyl-3(2H)-pyridazinone (3.10 g) was dissolved in acetic acid (30.0 ml), and bromine (3.50 g, 22.0 mmol) was added dropwise to the solution over 10 minutes under heating at 100° C. with stirring. After the reaction solution was heated for 1 hour under reflux, the acetic acid was distilled away under reduced pressure, and water (100 ml) was added to the residues which were then extracted 5 times with ethyl acetate. The extracts were combined, dried over anhydrous magnesium sulfate and concentrated to give a crude product of 6-isopropyl-3(2H)-pyridazinone. The yield was 3.30 g. After the reaction solution was heated for 1 hour under reflux the acetic acid was distilled away under reduced pressure, and water (100 ml) was added to the residues which were then extracted 5 times with ethyl acetate dried over anhydrous magnesium sulfate concentrated

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

Procedure: 5-Methyl-4-oxohexanoic acid (3.60 g, 25.0 mmol) and anhydrous hydrazine (0.80 g, 26.0 mmol) were heated for 3 hours in ethanol (36.0 ml) under stirring. After the reaction solution was concentrated under reduced pressure, hexane was added to the residues to precipitate crystals, and the crystals were collected by filtration to give 4,5-dihydro-6-isopropyl-3(2H)-pyridazinone as crystals. The yield was 3.10 g. After the reaction solution was concentrated under reduced pressure, hexane was added to the residues to precipitate crystals the crystals were collected by filtration

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,5-Dihydro-6-isopropyl-3 (2H)-pyridazinone (3.10 g) was dissolved in acetic acid (30.0 ml), and bromine (3.50 g, 22.0 mmol) was added dropwise to the solution over 10 minutes under heating at 100° C. with stirring. After the reaction solution was heated for 1 hour under reflux, the acetic acid was distilled away under reduced pressure, and water (100 ml) was added to the residues which were then extracted 5 times with ethyl acetate. The extracts were combined, dried over anhydrous magnesium sulfate and concentrated to give a crude product of 6-isopropyl-3 (2H)-pyridazinone. The yield was 3.30 g. After the reaction solution was heated for 1 hour under reflux the acetic acid was distilled away under reduced pressure, and water (100 ml) was added to the residues which were then extracted 5 times with ethyl acetate dried over anhydrous magnesium sulfate concentrated

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

Procedure: 5-Methyl-4-oxohexanoic acid (3.60 g, 25.0 mmol) and anhydrous hydrazine (0.80 g, 26.0 mmol) were heated for 3 hours in ethanol (36.0 ml) under stirring. After the reaction solution was concentrated under reduced pressure, hexane was added to the residues to precipitate crystals, and the crystals were collected by filtration to give 4,5-dihydro-6-isopropyl-3 (2H)-pyridazinone as crystals. The yield was 3.10 g. After the reaction solution was concentrated under reduced pressure, hexane was added to the residues to precipitate crystals the crystals were collected by filtration