Furopyridines.<b>XXVIII</b>. Reactions of 3-bromo derivatives of furo[2,3-<i>b</i>]-, -[3,2-<i>b</i>]-, -[2,3-<i>c</i>]- and -[3,2-<i>c</i>]pyridine and their<i>N</i>-oxides
作者:Seiji Yamaguchi、Kazuaki Awajima、Yoshiro Hirai、Hajime Yokoyama、Shunsaku Shiotani
DOI:10.1002/jhet.5570350602
日期:1998.11
Bromination of 3-bromofuro[2,3-b]- 1a, -[3,2-b]- 1b and - [3,2-c]pyridine 1d afforded the 2,3-dibromo derivatives 2a, 2b and 2d, while the -[2,3-c]- compound 1c did not give the dibromo derivative. Nitration of 1a-d gave the 2-nitro-3-bromo compounds 3a-d. The N-oxides 4a-d of 1a-d were submitted to the cyanation with trimethylsilyl cyanide to yield the corresponding α-cyanopyridine compound 6a-d.
3-溴呋喃并[2,3-的溴化b ] - 1A, - [3,2- b ] - 1B和- [3,2- c ^ ]吡啶1D,得到2,3-二溴衍生物2a,图2b和2d中, -[2,3- c ]-化合物1c没有给出二溴衍生物。硝化1a-d得到2-硝基-3-溴化合物3a-d。所述Ñ -oxides 4A-D的1A-d被提交到氰化三甲基甲硅烷氰化物,得到相应的α氰基吡啶化合物6A-d 。氯化用氧氯化磷的4a和4d主要产生氯吡啶衍生物7a,7′a和7d,而4b和4c主要产生氯呋喃衍生物7′b和7′c,伴随着氯吡啶衍生物7b,7′b和7c的形成。用乙酸酐对4a和4b进行乙酰氧基化,得到乙酰氧基吡啶化合物8a,8'a和8b,而4c和4d得到乙酰氧基吡啶8'c,8'd和8'd,吡啶酮8c和8d,乙酰氧基呋喃8'c和二溴化合物9c和9'c。