O

MeOH Scheme 32

Ph2CO (108)

PhCOCOPh (109)

2.3 Cardiovascular, Diuretic and Hemotherapeutic Drugs

2.3.1 Cardiac Agents. The cardiotonic digitoxin (110) has been found to give (111) through intramolecular addition of the 14-hydroxy group to the conjugated double bond by irradiation in the solid state (Scheme 33).115 Ubidecarenone (112) has been found to be photolabile in the solid-state.116 (Z) 2-amino-5-chlorobenzophenoneamidinohydrazone acetate (113), an antiarrhythmically active compound, undergoes geometrical isomerisation and, more slowly, decomposition when exposed to light in aqueous solution.117 Antianginal and antiarrhythmic amiodarone (114) (Scheme 34) was found to deiodinate sequentially upon irradiation in deaerated ethanol to give (115) and finally the iodine-free ketone (116); in turn, the last compound underwent a-cleavage to give (117) when irradiated for a longer time.118 Formation or aryl radicals during the deiodination process was evidenced by a spin trapping study.119

(110) R= Tridigitoxoside residue

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