Catechol → 2-Chloro-3',4'-dihydroxyacetophenone
Reaction equation
[C:1]1([C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4])[OH:2].P(Cl)(Cl)(Cl)=O.[Cl:14][CH2:15][C:16](Cl)=[O:17]>O>[Cl:14][CH2:15][C:16]([C:6]1[CH:5]=[C:3]([OH:4])[C:1](=[CH:8][CH:7]=1)[OH:2])=[O:17]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 125 °C
Procedure
Similar to the procedures of R. W. Schayer (J. Am. Chem. Soc. 74, 2441 [1952]) and N. Levin et al. (J. Org. Chem. 7, 408-415 [1942]), but without an additional solvent, a mixture of 100 g catechol, 750 g (450 ml) of phosphorus oxychloride and 206 g (145 ml) of chloracetyl chloride was stirred at reflux temperature (ca. 125° C.) in an argon atmosphere for 4.5 hours. Then most of the volatiles were distilled off at 80° C. (bath temperature) and, finally, under reduced pressure. To the nearly intractable dark mass were added at ca 80° C. 200 ml of water upon which the mixture became stirabel again. 600 ml of cold (0° C.) water were added in portions to control the exothermic reaction. When all of the water was added and the exothermic reaction had ceased the mixture was stirred for 2 hours under reflux. Upon stirring over night without further heating 125 g of crude product precipitated as dark brown crystals with a purity of about 90% (yield ca. 65%).
Workup
- distillationThen most of the volatiles were distilled off at 80° C. (bath temperature)
- additionTo the nearly intractable dark mass were added at ca 80° C
- addition600 ml of cold (0° C.) water were added in portions
- customthe exothermic reaction
- customthe exothermic reaction
- stirringwas stirred for 2 hours
- temperatureunder reflux
- stirringUpon stirring over night
- customprecipitated as dark brown crystals with a purity of about 90% (yield ca. 65%)
Sources & evidence
- ORD record
- ord-17b66296efa64e419a66d617c2438231
- Source dataset
- uspto-grants-2011_09
- Patent number
- US08017815B2
Reaction notes
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