6-chloro-1-(tetrahydro-pyran-2-yl)-3-vinyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid ethyl ester 、
碘苯 以6-chloro-3-((E)-styryl)-1-(tetrahydro-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid ethyl ester was obtained (2.8 g, 65%) as a yellow solid的产率得到6-chloro-3-((E)-styryl)-1-(tetrahydro-pyran-2-yl)-1 H-pyrazolo[3,4-b]pyridine-4-carboxylic acid ethyl ester