1: 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester hydrochloride With triethylamine in dichloromethane T=0°C; 10 h; 2: di-tert-butyl dicarbonate in dichloromethane T=0 - 25°C;

1: imidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester With lithium borohydride in 1,4-dioxane T=25 - 60°C; 0.5 h; 2: With hydrogenchloride in 1,4-dioxane; water T=0°C; Acidic conditions; 3: di-tert-butyl dicarbonate With triethylamine in dichloromethane T=25°C; 16 h; Product distribution / selectivity;

in dichloromethane T=20°C; 2 h;

methanol; lithium hydroxide hydrate in water T=0 - 25°C;