Ethyl Bromide → 6-(3-ethoxyphenyl)-2-ethyl-3(2H)-pyridazinone

HRID 1954001Notes

Reaction equation

HRID 1954001 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([C:8]2[CH:9]=[CH:10][C:11](=[O:14])[NH:12][N:13]=2)[CH:5]=[CH:6][CH:7]=1.C(=O)([O-])[O-].[K+].[K+].[CH2:21](Br)[CH3:22].N1N[C:26](=O)[CH:27]=CC=1>C(O)C>[CH2:26]([O:1][C:2]1[CH:3]=[C:4]([C:8]2[CH:9]=[CH:10][C:11](=[O:14])[N:12]([CH2:21][CH3:22])[N:13]=2)[CH:5]=[CH:6][CH:7]=1)[CH3:27]

Participants

6

Reactant 4

HCID 6332Ethyl Bromide2×HCID 11430Potassium CarbonateHCID 681533(2H)-PyridazinoneHCID 198846786-(3-Hydroxyphenyl)pyridazin-3(2H)-one

Product 1

HCID 232957546-(3-ethoxyphenyl)-2-ethyl-3(2H)-pyridazinone

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

To a 2 liter 4-neck round bottom flask, stirring under a nitrogen atomsphere, was charged 50.0 g (1.0 eq., 0.266 moles) of 6-(3-hydroxyphenyl)-3(2H)-pyridazinone in 500 ml of ethanol followed by 73.4 g of potassium carbonate (2.0 eq., 0.53 moles) and 58.0 g of ethyl bromide (2.0 eq., 0.53 moles) in 50 ml of ethanol. The reaction was stirred at reflux, 70° C.-72° C. for 6 hr. with monitoring by glc. After 6 hr. 5.8 g of ethylbromide was added (0.2 eq., 53 mmoles) and after stirring for an addtional 15 hr. at reflux glc indicated all the starting pyridazinone was consumed. The reaction was worked up by vacuum filtering the mixture while still warm and washing the solid with 2×150 ml of ethanol. The filtrate was concentrated by evaporation under reduced pressure to afford 67.3 g of 6-(3-ethoxyphenyl)-2-ethyl-3(2H)-pyridazinone as a brown oil which solidified.

Workup

  1. stirringThe reaction was stirred
  2. temperatureat reflux, 70° C.-72° C. for 6 hr
  3. stirringafter stirring for an addtional 15 hr
  4. temperatureat reflux glc
  5. customwas consumed
  6. filtrationfiltering the mixture
  7. temperaturewhile still warm
  8. washwashing the solid with 2×150 ml of ethanol
  9. concentrationThe filtrate was concentrated by evaporation under reduced pressure

Sources & evidence

ORD record
ord-9d11393bb9814784b6d9541792bf362a
Source dataset
uspto-grants-2000_09
Patent number
US06121251

Reaction notes

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