1: 1,2-dihydro-6-methyl-2-oxo-3-pyridinecarbonitrile With n-butyllithium; diisopropylamine in tetrahydrofuran; hexanes T=-50 - 43°C; 2.25 h; 2: 1-bromo-butane in tetrahydrofuran; hexanes T=-50 - 25°C; 1 h;