Pyrazolo[3,4-<i>b</i>]pyridines: Syntheses, reactions, and nuclear magnetic resonance spectra
作者:Brian Maurice Lynch、Misbahul Ain Khan、Huk Chia Teo、Francisco Pedrotti
DOI:10.1139/v88-074
日期:1988.3.1
2-Chloro-3-formylpyridine (2-chloronicotinaldehyde) was obtained by reduction of 2-chloro-3-cyanopyridine by Raney nickel and formic acid (3 1); this intermediate is inaccessible by the above N-oxidation route (peroxyacid oxidation of 3-formylpyridine yields pyridine-N-oxide 3-carboxylic acid). In the synthesis of the parent 1 from 2-chloro-3-formylpyridine, the yield was prejudiced by the formation
2-氯-3-甲酰基吡啶(2-氯烟醛)由雷尼镍和甲酸(3 1)还原2-氯-3-氰基吡啶得到;该中间体无法通过上述 N-氧化途径获得(3-甲酰基吡啶的过氧酸氧化产生吡啶-N-氧化物 3-羧酸)。在由 2-氯-3-甲酰基吡啶合成母体 1 时,收率受到吖嗪物质 11 的形成的影响。