Sulfuric Acid → 4-Acetyl-2-methylbenzenediazonium sulfate

HRID 1848278Notes

Reaction equation

HRID 1848278 reaction equation
[S:1](=[O:5])(=[O:4])([OH:3])[OH:2].[C:6]([C:9]1[CH:15]=[CH:14][C:12]([NH2:13])=[C:11]([CH3:16])[CH:10]=1)(=[O:8])[CH3:7].[N:17]([O-])=O.[Na+].[NH2:21]C(N)=O>O.C(#N)C>[S:1]([O-:5])([O-:4])(=[O:3])=[O:2].[C:6]([C:9]1[CH:15]=[CH:14][C:12]([N+:13]#[N:17])=[C:11]([CH3:16])[CH:10]=1)(=[O:8])[CH3:7].[C:6]([C:9]1[CH:15]=[CH:14][C:12]([N+:13]#[N:21])=[C:11]([CH3:16])[CH:10]=1)(=[O:8])[CH3:7]

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 1176UreaHCID 133555151-(4-Amino-3-methylphenyl)ethanoneHCID 23668193Sodium Nitrite

Product 1

HCID 866421834-Acetyl-2-methylbenzenediazonium sulfate

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6342AcetonitrileSolvent

Conditions

Temperature
0 °C

Procedure

27.0 g of acetonitrile was added to a sulfuric acid solution of 27.0 g (181 mmol) of 4-acetyl-2-methylaniline, and the mixture was cooled to 0° C. An aqueous solution in which 13.1 g (190 mmol) of sodium nitrite was dissolved into 26.2 g of water was added in dropwise to the mixture. After reacting the resultant mixture for 1 hour at 0° C., an aqueous solution in which 1.1 g (18 mmol) of urea was dissolved into 2.2 g of water was added in dropwise, and the mixture was further stirred for 30 minutes to obtain an aqueous solution of 4-acetyl-2-methylbenzenediazonium sulfate. 5.18 g (36 mmol) of copper bromide, 62.2 g (362 mmol) of 47% hydrobromic acid and 81.0 g of acetonitrile were fed into another reactor. The aqueous solution of 4-acetyl-2-methylbenzenediazonium sulfate was added to this mixture in dropwise over 1 hour with stirring at 50° C. After adding in dropwise, the mixture was reacted for 1 hour at 50° C. Then, 81 g of toluene was added and the mixture was stirred for 30 minutes, and the water phase was separated. 54 g of toluene was added to the water phase and extracted again. The combined toluene solution was washed twice with 54 g of 14% aqueous ammonia and once with 54 g of water to obtain a toluene solution of 4′-bromo-3′-methylacetophenone. After removing the solvent by distilling under reduced pressure, the residue was distilled under reduced pressure of 1.5 kPa. 32.8 g of the obtained fraction which was collected in the range of outflow gas temperature from 130° C. to 137° C. was analyzed by HPLC. A percentage of relative area of 4′-bromo-3′-methylacetophenone was 99.1% (yield 84%).

Workup

  1. additionwas added in dropwise to the mixture
  2. customfor 1 hour
  3. customat 0° C.
  4. additionwas added in dropwise, and the mixture

Sources & evidence

ORD record
ord-9559db9a22a6447c96706fd713f3d2e0
Source dataset
uspto-grants-2015_02
Patent number
US08952175B2

Reaction notes

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