limited as long as the reaction exceeds and includes for example alcohols such as methanol ethanol propanol butanol and the like ethers such as diethylether tetrahydrofuran dioxane 1 2 dimethoxyethane and the like hydrocarbons such as benzene toluene cyclohexane hexane and the like amides such as n n dimethylformamide n n dimethylacetamide and the like halogenated hydrocarbons such as dichloromethane chloroform carbon tetrachloride 1 2 dichloroethane and the like nitrites such as acetonitrile propionitrile and the like sulfoxides such as dimethylsulfoxide and the like or a mixed solvent thereof and the like are preferred the reaction period is generally about 30 min to about 72 hr preferably about 3 hr to about 24 hr the reaction temperature is generally about u2212 20 to about 200 u00b0 c preferably about 20 to about 150 u00b0 c examples of the compound iv include r 5 6 dimethoxy 2 2 2 4 6 7 pentamethyl 3 4 methylphenyl 2 3 dihydro 1 benzofuran 5 yl isoindoline r 5 6 dimethoxy 2 2 2 4 6 7 pentamethyl 3 1 methylethylphenyl 2 3 dihydro 1 benzofuran 5 yl isoindoline r 5 6 dimethoxy 2 2 2 4 6 7 pentamethyl 3 4 bromophenyl 2 3 dihydro 1 benzofuran 5 yl isoindoline or a salt thereof the salt of the compound iv may be when the compound iv has an acidic group such as u2014 cooh and the like for example a metal salt an ammonium salt a salt with an organic base.