PT Journal AU Aly, AA El-Emary, TI Mourad, AE Khallaf Alyan, Z Bräse, S Nieger, M TI 5-Carbohydrazide and 5-carbonylazide of pyrazolo[3,4-b]pyridines as reactive intermediates in the synthesis of various heterocyclic derivatives SO Journal of chemical research PY 2019 BP 219 EP 229 VL 48 IS 7-8 DI 10.1177/1747519819861625 LA english ER