72159-27-4Relevant academic research and scientific papers
Pyrazolopyridines. The Preparation of 1-Protected-1H-pyrazolopyridines and Attempts to Remove the 1-Substituent. Some Reactions of 1-Benzyl-1H-pyrazolopyridine and its 7-Oxide
Dorgan, Roderick J.J.,Parrick, John,Hardy, Christopher R.
, p. 938 - 942 (2007/10/02)
1-Protected-1H-pyrazolopyridines and -1H-pyrazolopyridin-6(7H)-ones have been obtained from 1-substituted-5-aminopyrazoles , and the removal of the protecting groups has been investigated.Cyclisation of 1-substituted-5-aminopyrazoles with ethyl acetoacetate under acidic conditions or of the β-aminopropionic acid derivative (19) under the same conditions gave only the 1H-pyrazolopyridin-6(7H)-one isomer .N-Oxidation of 1-benzyl-1H-pyrazolopyridine (4) gave the 7-oxide (21) which yielded (20) and the less usual β-substitution product (22) with acetic anhydride.Nitration of either (4) or (21) gave only substitution at the para-position of the 1-benzyl substituent, but bromination or chlorination gave substitution at the 3-position of the heterocycle.
