1: (6-methyl-2-pyridinyl)carbamic acid,1,1-dimethylethyl ester With lithium diisopropyl amide in tetrahydrofuran; n-heptane; ethylbenzene T=-20°C; 1 h; 2: carbon dioxide in tetrahydrofuran; n-heptane; ethylbenzene T=-70 - 10°C; 3: With hydrogenchloride in tetrahydrofuran; n-heptane; ethylbenzene; water; ethyl acetate