1: (1-(tert-butoxycarbonyl)-(4S)-fluoro-(2R)-pyrrolidinyl)acetonitrile With sodium hydride in dimethyl sulfoxide; mineral oil T=18 - 25°C; 3 h; 2: 2,5-dibromo-pyridine in dimethyl sulfoxide; mineral oil T=120°C; 6.5 h;