Sulfuric Acid → 2-Chloro-4-hydroxybenzonitrile

HRID 2295376Notes

Reaction equation

HRID 2295376 reaction equation
[Cl:1][C:2]1[CH:9]=[C:8](N)[CH:7]=[CH:6][C:3]=1[C:4]#[N:5].S(=O)(=O)(O)[OH:12].N([O-])=O.[Na+].NC(N)=O>O>[Cl:1][C:2]1[CH:9]=[C:8]([OH:12])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 1176UreaHCID 887284-Amino-2-chlorobenzonitrileHCID 23668193Sodium Nitrite2×

Product 1

HCID 5927972-Chloro-4-hydroxybenzonitrileYield 33%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

The 2-chloro-4-aminobenzonitrile (57 g, 0.37 m) was added to a cold stirred solution of concentrated sulfuric acid (115 g) in water (1,000 ml). Then a cold solution of sodium nitrite (26.5 g, 0.38 m) in water (250 ml) was added to the suspension solution at a temperature between 0° and 6° C. Upon addition of the sodium nitrite, stirring continued for approximately three hours at which time urea (3 g) was added to the reaction mixture. The reaction mixture reacted at a temperature between 69° and 76° C. for approximately three hours. The reaction product was filtered and crystallized from water to yield the fifth step product 2-chloro-4-hydroxybenzonitrile (18.8 g, 33%, mp 157°-158° C.).

Workup

  1. additionwas added to the reaction mixture
  2. customThe reaction mixture reacted at a temperature between 69° and 76° C. for approximately three hours
  3. filtrationThe reaction product was filtered
  4. customcrystallized from water

Sources & evidence

ORD record
ord-024ffe6464b84f4c9eafcb59a0abf52f
Source dataset
uspto-grants-1984_01
Patent number
US04424371

Reaction notes

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