3-Amino-1,5-naphthalenedisulfonic acid → 3-Hydroxy-2-methylbenzoic Acid
Reaction equation
C([O:4][C:5]1[C:6]([CH3:14])=[C:7]([CH:11]=[CH:12][CH:13]=1)[C:8](Cl)=[O:9])(=O)C.NC1C=C(S(O)(=O)=O)C2C=CC=C(S(O)(=O)=[O:27])C=2C=1>O>[OH:4][C:5]1[C:6]([CH3:14])=[C:7]([CH:11]=[CH:12][CH:13]=1)[C:8]([OH:9])=[O:27]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
The present invention relates to a process for the preparation of 3-acetoxy-2-methylbenzoyl chloride by reacting an alkali metal salt of 3-aminonaph-thalene-1,5-disulfonic acid with alkali metal hydroxide and water in the weight ratio 1:(1 to 1.6):(1 to 1.6) at 220 to 320° C. to give the dialkali metal salt of the 3-hydroxy-2-methylbenzoic acid, separating off insoluble constituents from the reaction mixture, then adjusting the reaction mixture to a pH of 11.5 to 13.5 by addition of acid and reacting with acetic anhydride at -5 to +25° C., precipitating the 3-acetoxy-2-methylbenzoic acid by addition of acid, separating off the 3-acetoxy-2-methylbenzoic acid and reacting it with an inorganic acid chloride to give 3-acetoxy-2-methylbenzoyl chloride.
Sources & evidence
- ORD record
- ord-e94eb2f5e2384d04ae7d27028f59b298
- Source dataset
- uspto-grants-2000_04
- Patent number
- US06051732
Reaction notes
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