Step D: Preparation of 3-amino-5,6-dimethylpyridine
A solution of 2-chloro-5,6-dimethyl-3-nitropyridine (5 g, 26.8 mmol), triethylamine (10 mL), and 5% Pd/C catalyst (0.4 g) in methanol (200 mL) was subjected to a shaking reaction under a hydrogen atmosphere (45-40 psi) for 16 hours. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth plug and the filtrate was concentrated under reduced pressure. The resulting residue was ground with a chloroform-saturated chloroform solution and the resulting slurry was again filtered through a diatomaceous earth plug. The filtrate was concentrated under vacuum to give 3.2 g (100% yield) of 3-amino-5,6-dimethylpyridine.
