
TY  - JOUR
A1  - Armarego, WLF 
T1  - The Synthesis of 5,7-Dichlorocoumaran-3-one and Related Problems
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1960
VL  - 13
IS  - 1
SP  - 95
EP  - 102
KW  - 
UR  - https://doi.org/10.1071/CH9600095 
N2  - 5,7-Dichlorocoumaran-3-one has been prepared from methyl 2-hydroxy-3,5-dichlorobenzoate by a three stage synthesis.   It could not be prepared by (i) intramolecular cyclization of 2,4-dichlorophenoxy- acetic acid or 2,4-dichlorophenoxyacetyl chloride or (ii) by the reaction of &#969;-bromo-2-hydroxy-3,5-dichloroacetophenone with bases.   The reaction of 2,4-dichlorophenoxyacetic acid with phosphorus pentoxide in benzene gave 2,4-dichlorophenol, 2',4'-dichlorophenyl 2,4-dichlorophenoxyacetate, and diphenylmethane. By the use of 14C-labelled acids the methylene carbon atom of the diphenylmethane was shown to be derived from the methylene carbon atom of 2,4-dichlorophenoxyacetic acid. A possible mechanism is proposed for this reaction. 
ER  -

