Ammonia → 6-Isopropyl-3-pyridazinone

HRID 1042003Notes

Reaction equation

O.[C:2]([OH:6])(=O)[CH:3]=[O:4].[CH3:7][C:8]([CH:10]([CH3:12])[CH3:11])=O.[NH3:13].[OH-].[NH3+:15]N>O>[OH:6][CH:2]1[C:10]([CH3:12])([CH3:11])[C:8]([CH3:7])=[N:15][NH:13][C:3]1=[O:4].[CH:10]([C:8]1[CH:7]=[CH:3][C:2](=[O:6])[NH:13][N:15]=1)([CH3:12])[CH3:11]

Participants

Conditions

Temperature: 120 °C

Procedure

7.1 A mixture of 14.4 g (157 mmol) of glyoxylic acid monohydrate and 50 ml (464 mmol) of isopropyl methyl ketone is heated at 120° C. with stirring for two hours. The reaction mixture is cooled to 40° C., and 70 ml of water and 12 ml of 32% aqueous ammonia solution are added. This mixture is extracted three times with dichloromethane. 7.55 ml (155 mmol) of hydrazinium hydroxide are added to the aqueous phase, and the mixture is heated at reflux for 18 hours. The reaction mixture is cooled to room temperature and extracted with dichloromethane. The organic phase is dried over sodium sulfate and evaporated. The residue is chromatographed on a silica-gel column with petroleum ether/tert-butyl methyl ether as eluent, giving 4-hydroxy-5,5,6-trimethyl-4,5-dihydro-2H-pyridazin-3-one as colourless crystals (ESI 157) and 6-isopropyl-2H-pyridazin-3-one as colourless crystals (ESI 139).

Workup

temperatureThe reaction mixture is cooled to 40° C.
extractionThis mixture is extracted three times with dichloromethane
temperaturethe mixture is heated
temperatureat reflux for 18 hours
temperatureThe reaction mixture is cooled to room temperature
extractionextracted with dichloromethane
dry with materialThe organic phase is dried over sodium sulfate
customevaporated
customThe residue is chromatographed on a silica-gel column with petroleum ether/tert-butyl methyl ether as eluent

Sources & evidence

ORD record: ord-114b1f76192349a18d6fceeb5801be28
Source dataset: uspto-grants-2013_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08557813B2

Reaction notes

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