Hydrogen Bromide → 3-Hydroxyproquazone

HRID 1834761Notes

Reaction equation

HRID 1834761 reaction equation
[CH:1]([N:4]1[C:13]2[C:8](=[CH:9][CH:10]=[C:11]([CH3:14])[CH:12]=2)[C:7]([C:15]2[CH:20]=[CH:19][CH:18]=[C:17]([O:21]C)[CH:16]=2)=[N:6][C:5]1=[O:23])([CH3:3])[CH3:2].Br>O>[CH:1]([N:4]1[C:13]2[C:8](=[CH:9][CH:10]=[C:11]([CH3:14])[CH:12]=2)[C:7]([C:15]2[CH:20]=[CH:19][CH:18]=[C:17]([OH:21])[CH:16]=2)=[N:6][C:5]1=[O:23])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 46200211-isopropyl-7-methyl-4-(m-methoxyphenyl)-2(1H)-quinazolinone

Product 1

HCID 632573-Hydroxyproquazone

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 0.5 g of 1-isopropyl-4-(3-methoxyphenyl)-7-methyl-2(1H)-quinazolinone is added 5 ml of 48% (aqueous) hydrobromic acid (heat evolves and the solution turns yellow). The mixture is then refluxed for 6 hours. The mixture is cooled to room temperature, then 95 ml of water added, and the resulting mixture extracted thrice with 100 ml portions of a benzene: n-butanol (4:1) mixture each extract is retained separately. Each extract is washed 4 times with 75 ml portions of water (the pH of the last wash should be neutral). The extracts are combined and evaporated to dryness to obtain a residue which is then crystallized from methanol and ethyl acetate (1:1) to obtain 1-isopropyl-4-(3-hydroxyphenyl)-7-methyl-2(1H)-quinazolinone; m.p. 270°-272°, which yields refined product upon recrystallization from methanol; m.p. 274°-275° C.

Workup

  1. temperatureheat evolves
  2. temperatureThe mixture is then refluxed for 6 hours
  3. extractionthe resulting mixture extracted thrice with 100 ml portions of a benzene: n-butanol (4:1) mixture each extract
  4. washEach extract is washed 4 times with 75 ml portions of water (the pH of the
  5. washlast wash should
  6. customevaporated to dryness
  7. customto obtain a residue which
  8. customis then crystallized from methanol and ethyl acetate (1:1)

Sources & evidence

ORD record
ord-f32e91efecf9400ba357fd1f3fb770a8
Source dataset
uspto-grants-1978_01
Patent number
US04071516

Reaction notes

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