Synthesis of Some New Dihalophenyl- and Dihalobenzylisocoumarins and Their (dl)-3,4-Dihydroderivatives

Authors: ZAHID SHAFIQ, MUHAMMAD ARFAN, NASIM HASAN RAMA, SHAHID HAMEED, GHULAM ABBAS, MUHAMMAD TAHIR HUSSAIN

Abstract: 3-Dihalophenyl- and dihalobenzylisocoumarins (3a-c) were synthesized by condensation of homophthalic acid (1) with dihalobenzoyl- and dihalophenylacetyl chlorides (2a-c), respectively. The alkaline hydrolysis of these isocoumarins (2a-c) afforded keto-acids (4a-c). (dl)-3-(Dihalophenyl)- and (dl)-3-(dihalobenzyl)- 3,4-dihydroisocoumarins (6a-c) were obtained by reduction of keto-acids (4a-c) to racemic hydroxy-acids (5a-c) followed by cyclodehydration using acetic anhydride.

Keywords: Dihaloisocoumarins, Dihydrodihaloisocoumarins, synthesis.

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