Thioglycolic Acid → 7-Chloro-1-benzothiophene-2-carboxylic acid
Reaction equation
Cl[C:2]1[C:9]([Cl:10])=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=O.[C:11]([OH:15])(=[O:14])[CH2:12][SH:13]>[OH-].[K+].O>[Cl:10][C:9]1[C:2]2[S:13][C:12]([C:11]([OH:15])=[O:14])=[CH:4][C:3]=2[CH:6]=[CH:7][CH:8]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 125 °C
Procedure
In a glass pressure bottle, 2,3-dichlorobenzaldehyde (17.5 g, 0.1 mol) was added to a solution of thioglycolic acid (7.0 ml) in potassium hydroxide (12.5 g) and water (100 ml). The bottle was then sealed and heated in a hot oil bath to 125±5° C. for 1.25 hours. The bottle was then removed from the hot oil bath and cooled. A pale yellow precipitate was obtained in the bottle. At ambient temperature, the bottle was opened and sufficient water was added to dissolve the precipitate. The resultant aqueous material was washed with ether and then acidified with hydrochloric acid to produce a pale yellow solid. The pale yellow solid was collected on a filter, washed with water and dried, to produce 17.2 g of 7-chloro-2-benzo[b]thiophenecarboxylic acid (83.8% yield, mp 262-265° C.)
Workup
- customThe bottle was then sealed
- customThe bottle was then removed from the hot oil bath
- temperaturecooled
- customA pale yellow precipitate was obtained in the bottle
- customAt ambient temperature
- dissolutionto dissolve the precipitate
- washThe resultant aqueous material was washed with ether
- customto produce a pale yellow solid
- customThe pale yellow solid was collected on a filter
- washwashed with water
- customdried
Sources & evidence
- ORD record
- ord-51939968364c4c689fdfa933467d83a3
- Source dataset
- uspto-grants-1999_10
- Patent number
- US05965749
Reaction notes
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