(i) NaNO2, aq. HCl, aq. HBF4, (ii) (pyrolysis); Multistep reaction;

1: 1.) Mg; 2.) CdCl2 / 1.) diethyl ether; 2.) benzene, Et2O, 45 min, reflux; 3.) benzene, reflux, 1.5 h; overnight, RT 2: 76 percent / KOH / aq. ethanol View Scheme

1: 2-Bromo-4-fluoro toluene With magnesium; lithium chloride in tetrahydrofuran T=20°C; Inert atmosphere; 2: N-cyano-N-phenyl-p-methylbenzenesulfonamide in tetrahydrofuran T=0 - 20°C; Inert atmosphere;

1: With N-bromosuccinmide; dibenzoyl peroxide in ethyl acetate T=80°C; 1 h; 2: With 1,3,5,7-tetra-azatricyclo[5.1.1.13,5]decane in water; acetic acid T=100°C; 1 h; 3: With hydrogenchloride in water 1 h;

1: NBS, Br2 View Scheme

N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile in tetrachloromethane 21 h; Heating / reflux;

1: NBS, Br2 3: aq. KOH View Scheme

potassium permanganate; magnesium sulfate

1.1: 62 percent / N-bromosuccinimide; benzoyl peroxide / CCl4 / 18 h / Heating; IR illumination 2.1: sodium hydride / 1,2-dimethoxy-ethane / 1 h / 20 °C 2.2: 40 percent / 1,2-dimethoxy-ethane / 1.5 h / Heating 3.1: aq. KOH / 4.5 h / Heating 3.2: 91 percent / aq. H2SO4 / 18 h / Heating 4.1: oxalyl chloride / CH2Cl2 / 18 h / 20 °C 5.1: aluminum chloride / CH2Cl2 / 2 h / Heating View Scheme

n-butyllithium in tetrahydrofuran; hexane T=-78°C;