1: lithium 3,4-dimethoxybenzoate With 2,2,6,6-tetramethylpiperidinyl-lithium in tetrahydrofuran T=0°C; 2 h; 2: methyl iodide in tetrahydrofuran T=0 - 66°C; 3 h; 3: With hydrogenchloride; water in diethyl ether pH=1 - 2;