Hydrogen Bromide → 6-(3-hydroxyphenyl)-2-ethyl-3(2H)-pyridazinone

HRID 1954002Notes

Reaction equation

HRID 1954002 reaction equation
C([O:3][C:4]1[CH:5]=[C:6]([C:10]2[CH:11]=[CH:12][C:13](=[O:18])[N:14]([CH2:16][CH3:17])[N:15]=2)[CH:7]=[CH:8][CH:9]=1)C.Br>>[OH:3][C:4]1[CH:5]=[C:6]([C:10]2[CH:11]=[CH:12][C:13](=[O:18])[N:14]([CH2:16][CH3:17])[N:15]=2)[CH:7]=[CH:8][CH:9]=1

Participants

3

Reactant 2

HCID 260Hydrogen Bromide3×HCID 232957546-(3-ethoxyphenyl)-2-ethyl-3(2H)-pyridazinone

Product 1

HCID 154770546-(3-hydroxyphenyl)-2-ethyl-3(2H)-pyridazinoneYield 81.9%

Procedure

To a 2 liter 3-neck round bottom flask, stirring under a nitrogen atomsphere, was charged 64.9 g (1.0 eq., 0.266 moles) of 6-(3-ethoxyphenyl)-2-ethyl-3(2H)-pyridazinone followed by 250 ml of 48% HBr. The reaction was stirred at 90° C.-95° C. with monitoring by glc. After 7 hr. an additional 100 ml of 48%HBr was added and after an additional 10 hr. 100 ml of 48%HBr was added. After 33 hr. of stirring at 90° C.-95° C. the reaction was cooled to room temperature and quenched by pouring into 500 ml of ice water. An oil formed initially which on standing solidified. The solid was broken into small pieces and vacuum filtered, washed with 3×200 ml water and dried in a vacuum oven at ambient temperature and afforded 47.0 g of 6-(3-hydroxyphenyl)-2-ethyl-3(2H)-pyridazinone as a brown red solid. (81.9% yield).

Workup

  1. stirringThe reaction was stirred at 90° C.-95° C. with monitoring by glc
  2. waitAfter 33 hr
  3. stirringof stirring at 90° C.-95° C. the reaction
  4. customquenched
  5. additionby pouring into 500 ml of ice water
  6. customAn oil formed initially which
  7. filtrationfiltered
  8. washwashed with 3×200 ml water
  9. customdried in a vacuum oven at ambient temperature

Sources & evidence

ORD record
ord-901daf6e2423410585cf4db8fb52f0ef
Source dataset
uspto-grants-2000_09
Patent number
US06121251

Reaction notes

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