in dichloromethane N2 atmosphere addn. of Fe-compd. to soln. of org. compd. in CH2Cl2, stirring (25°C, 12 h); diln. with cold ether, filtration, washing (ether), drying (vac.);

tetrafluoroboric acid diethyl ether complex; 2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane mixt. of reagents was stirred at -78°C for 30 min; mixt. was poured into Et2O, ppt. was sepd. and washed with Et2O, dissolved in H2O, satd. aq. NH4PF6 was added;; filtered, dried under vac.; elem. anal.;;

NH4BF4; Tl(OCOCF3)3 in neat (no solvent) the complex was ground in small portions with Tl(CF3CO2)3, after mixing solid NH4BF4 was added and grinding continued, concd. H2SO4 was added followed by H2O, aq. soln. was sepd.and washed with Et2O, satd. aq. NH4PF6 was added;; ppt. was filtered, washed with Et2O, dried under vac.; mixt. of isomers was obtained (50percent yield, 12:1);