1: 1-chloro-4-bromobenzene With n-butyllithium in tetrahydrofuran T=-78°C; 0.666667 h; Inert atmosphere; 2: 1,3,5-cycloheptatrienylium tetrafluoroborate in tetrahydrofuran T=20°C; 14 h; Inert atmosphere;

1: methanol 2: (i) Mg, Et2O, (ii) /BRN= 2040337/ View Scheme

(i) Mg, Et2O, (ii) /BRN= 1931101/; Multistep reaction;

(i) Mg, Et2O, (ii) /BRN= 2040337/; Multistep reaction;