3-Chloro-o-cresol → 3-Hydroxy-2-methylbenzonitrile

HRID 1416073Notes

Reaction equation

HRID 1416073 reaction equation
Cl[C:2]1[C:3]([CH3:9])=[C:4]([OH:8])[CH:5]=[CH:6][CH:7]=1.[Cu][C:11]#[N:12]>N1C=CC=CC=1>[OH:8][C:4]1[C:3]([CH3:9])=[C:2]([CH:7]=[CH:6][CH:5]=1)[C:11]#[N:12]

Participants

4

Reactant 2

HCID 148563-Chloro-o-cresolHCID 178418546HCID 178418546, compound

Product 1

HCID 226160943-Hydroxy-2-methylbenzonitrile

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A further process starts from 3-chloro-2-methylphenol (Cresp et al., J. Chem. Soc. Perkin Trans.1, 2435(1974)). This is reacted with copper(I) cyanide in pyridine at boiling heat to give 3-hydroxy-2-methylbenzonitrile. In the second stage, the nitrile is hydrolyzed to 3-hydroxy-2-methylbenzoic acid (2) in 18 hours in a boiling mixture of water, glacial acetic acid and concentrated sulfuric acid. The first stage of this process has the significant disadvantage that very toxic copper(I) cyanide is employed--under the reaction conditions toxic hydrogen cyanide gas can escape from the reaction mixture. Harmful pyridine is employed as a solvent. The reaction is distinguished by difficult working up and a high yield of toxic salts. In the second stage (amide hydrolysis), a very long reaction time is necessary. At the very high reaction temperatures, the acidic reaction medium is very corrosive to the materials customarily employed in chemical plants.

Workup

  1. temperatureat boiling heat

Sources & evidence

ORD record
ord-8ad6a947cfba48ccb9656c52e3aa9098
Source dataset
uspto-grants-1999_06
Patent number
US05910605

Reaction notes

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