Chlorosulfonic acid → 7-Methyl-9-oxothioxanthene-3-carboxylic acid

HRID 1427169Notes

Reaction equation

HRID 1427169 reaction equation
[C:1]1([CH3:20])[CH:6]=[CH:5][C:4]([S:7][C:8]2[CH:13]=[C:12]([C:14]([OH:16])=[O:15])[CH:11]=[CH:10][C:9]=2[C:17]([OH:19])=O)=[CH:3][CH:2]=1.ClS(O)(=O)=O>O>[CH3:20][C:1]1[CH:2]=[C:3]2[C:4]([S:7][C:8]3[CH:13]=[C:12]([C:14]([OH:16])=[O:15])[CH:11]=[CH:10][C:9]=3[C:17]2=[O:19])=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 24638Chlorosulfonic acidHCID 105894221,4-Benzenedicarboxylic acid, 2-[(4-methylphenyl)thio]-

Product 1

HCID 108259057-Methyl-9-oxothioxanthene-3-carboxylic acidYield 96.7%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
10 °C

Procedure

The 2-(p-tolylthio)benzene-1,4-dicarboxylic acid is transferred slowly to a flask, containing 100 ml of chlorosulfonic acid. The temperature is maintained between the 5 and 10° C. with an ice-bath. At the end of the addition, the solution is left to rest for maturation and after 1 hour is poured in water and ice. The precipitate is filtered, washed with water and dried in a vacuum oven obtaining 19.69 g (yield: 96.7%) of 7-methyl-9-oxo-thioxanthene-3-carboxylic acid as a yellow solid. Melting point>250° C.

Workup

  1. additionAt the end of the addition
  2. waitthe solution is left
  3. filtrationThe precipitate is filtered
  4. washwashed with water
  5. customdried in a vacuum oven

Sources & evidence

ORD record
ord-b459385a4df2413fb366583426923c83
Source dataset
uspto-grants-2015_01
Patent number
US08933142B2

Reaction notes

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