Two routes were employed to synthesize unsubstituted furo[2,3-b]pyridine (IV). The first method started with ethyl 5-aminofuro[2,3-b] pyridine-2-carboxylate (1) and involved successive deamination, hydrolysis, and decarboxylation. The second method began with 5-nitrofuro[2,3-b ]-pyridine-2-carboxylic acid (V) and consisted of successive decarboxylation, reduction, and deamination reactions.

中文翻译：

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呋喃并[2,3- b ]吡啶的合成

采用两种途径合成未取代的呋喃并[2,3- b ]吡啶（IV）。第一种方法始于5-氨基呋喃[2,3- b ]吡啶-2-羧酸乙酯（1），包括连续的脱氨基，水解和脱羧作用。第二种方法以5-硝基呋喃并[2,3- b ]-吡啶-2-羧酸（V）开始，由连续的脱羧，还原和脱氨基反应组成。