potassium permanganate

1: 4-chloro-2-methylbenzoic acid With 2,2,6,6-tetramethylpiperidinyl-lithium in tetrahydrofuran; hexane T=-50°C; 1 h; 2: methyl iodide in tetrahydrofuran; hexane T=-50 - 20°C;

1: 2-chloro-5-carboxybenzene With 2,2,6,6-tetramethylpiperidinyl-lithium in tetrahydrofuran; hexane T=-78°C; 4 h; 2: methyl iodide in tetrahydrofuran; hexane T=-78 - 20°C;

1.1: TMEDA / hexane; cyclohexane; tetrahydrofuran / 0.5 h / -78 °C 1.2: 73 percent Spectr. / hexane; cyclohexane; tetrahydrofuran / -78 - 20 °C 2.1: lithium 2,2,6,6-tetramethylpiperidide / tetrahydrofuran; hexane / 1 h / -50 °C 2.2: 60 percent / tetrahydrofuran; hexane / -50 - 20 °C View Scheme

1: 2,2,6,6-tetramethylpiperidinyl-lithium; 2-chloro-5-carboxybenzene in tetrahydrofuran; hexane T=-50°C; 4 h; 2: methyl iodide in tetrahydrofuran; hexane T=-50 - 20°C;

sulfuric acid

1: (i) NaNO2, aq. HCl, (ii) /BRN= 4652394/, CuCN 2: aq. H2SO4 View Scheme

phosphorus pentachloride