O,O-Diethyl dithiophosphate → 6-(3-Bromophenyl)pyridazin-3(2H)-one

HRID 746280Notes

Reaction equation

HRID 746280 reaction equation
CCOP(S)(OCC)=S.[Br:10][C:11]1[CH:12]=[C:13]([C:17](=O)[CH:18]=[CH:19][C:20]([OH:22])=O)[CH:14]=[CH:15][CH:16]=1.BrC1C=C(C(=O)CC(SP(OCC)(OCC)=S)C(O)=O)C=CC=1.O.[NH2:48][NH2:49]>C(O)C>[Br:10][C:11]1[CH:12]=[C:13]([C:17]2[CH:18]=[CH:19][C:20](=[O:22])[NH:48][N:49]=2)[CH:14]=[CH:15][CH:16]=1

Participants

6

Reactant 4

HCID 9274O,O-Diethyl dithiophosphateHCID 24654Hydrazine hydrate (1:1)HCID 13420321HCID 13420321, compoundHCID 533962204-(3-Bromophenyl)-4-oxobut-2-enoic acid

Product 1

HCID 128816476-(3-Bromophenyl)pyridazin-3(2H)-oneYield 38.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

1.12 g (0.006 mole) of O,O-diethyldithiophosphoric acid were added, at room temperature, to a suspension of 1.28 g of 4-(3-bromophenyl)-4-oxo-2-butenoic acid in 10 ml of ethanol, and then the mixture was stirred for 10 minutes. Formation of 4-(3-bromophenyl)-2-diethoxyphosphinothioylthio-4-oxobutanoic acid was confirmed by thin layer chromatography but the compound was not separated from the reaction mixture. 0.3 g (0.006 mole) of hydrazine monohydrate was added to the reaction mixture, which was then stirred overnight at room temperature. At the end of this time, the crystals which had precipitated were collected by filtration and washed with ethanol to give 0.48 g of the desired 6-(3-bromophenyl)-3(2H)pyridazinone. The filtrate was concentrated and then subjected to column chromatography through silica gel eluted with a 4:1 by volume mixture of benzene and ethyl acetate, to give a further 0.48 g of the product, a total of 0.96 g (yield 76%) of the product, melting at 202°-204° C.

Workup

  1. customthe compound was not separated from the reaction mixture
  2. stirringwas then stirred overnight at room temperature
  3. customAt the end of this time, the crystals which had precipitated
  4. filtrationwere collected by filtration
  5. washwashed with ethanol

Sources & evidence

ORD record
ord-19331db381ee49f2911f2d945530ba50
Source dataset
uspto-grants-1986_07
Patent number
US04603201

Reaction notes

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