88.

Craig Method

L. C. Craig, J. Am. Chem. Soc. 56, 231 (1934).

Introduction of a halogen into the α-position of aminopyridines by treatment with sodium nitrite in hydrohalic acid followed by warming:

H. S. Mosher, Heterocyclic Compounds 1, 515, 555 (1950); H. E. Mertel in The Chemistry of Heterocyclic Compounds, A. Weissberger, Ed., Pyridine and its Derivatives Part Two, E. Klingsberg, Ed. (Interscience, New York, 1961) p 334.