3-Chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid → 3-Chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid anhydride

HRID 580279Notes

Reaction equation

HRID 580279 reaction equation
[Cl:1][C:2]1[C:6]2=[N:7][C:8]([C:14]([OH:16])=[O:15])=[C:9]([C:11]([OH:13])=O)[CH:10]=[C:5]2[S:4][CH:3]=1>C(OC(=O)C)(=O)C>[Cl:1][C:2]1[C:6]2=[N:7][C:8]3[C:14](=[O:15])[O:16][C:11](=[O:13])[C:9]=3[CH:10]=[C:5]2[S:4][CH:3]=1

Participants

3

Reactant 1

HCID 148387283-Chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid

Product 1

HCID 137524853-Chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid anhydrideYield 89%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

3-Chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid (1.45 g) is heated at 85° to 90° C. for 30 minutes then 90° to 102° C. for 30 minutes in acetic anhydride (7 mL). The reaction is cooled, the solids filtered off and washed with ether to give 1.2 g of 3-chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid anhydride. The proton magnetic resonance spectrum is consistant with the structure.

Workup

  1. temperatureThe reaction is cooled
  2. filtrationthe solids filtered off
  3. washwashed with ether

Sources & evidence

ORD record
ord-dff90c93e6c643f7a17bd1236f4ad9cd
Source dataset
uspto-grants-1988_06
Patent number
US04752323

Reaction notes

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