1) 2-Alkyl (or aryl) oxazolo [5, 4-b] pyridines were prepared by distillation of 3-acylamino-2-hydroxypyridine which was obtained by acylation of 3-amino-2-hydroxypyridine (I). 2) 2-Aminoxazolo [5, 4-b] pyridine, which could not be obtained by the reaction of (I) with cyanogen bromide, was successfully prepared by heating (2-hydroxy-3-pyridyl) thiourea with mercuric oxide in water. 3) Oxazolo [5, 4-b] pyridin-2 (1H)-one was prepared by distillation of (2-hydroxy-3-pyridyl) urethan and also the synthesis of 1-substituted oxazolo [5, 4-b] pyridin-2 (1H)-ones was established by treatment of 2-hydroxy-3-(substituted) aminopyridines with carbonyl chloride.