久久国产成人av_抖音国产毛片_a片网站免费观看_A片无码播放手机在线观看,色五月在线观看,亚洲精品m在线观看,女人自慰的免费网址,悠悠在线观看精品视频,一级日本片免费的,亚洲精品久,国产精品成人久久久久久久

分享

Sakai對(duì)甲苯磺酰腙環(huán)化反應(yīng)

 新用戶09324243 2024-11-09
α,α-二氯對(duì)甲苯磺酰腙與伯胺之間縮合環(huán)化制備1,4-二取代三氮唑的反應(yīng),稱為Sakai對(duì)甲苯磺酰腙環(huán)化反應(yīng),。該反應(yīng)由日本Sagami化學(xué)研究中心的Sakai Kunikazu研究室在1986年首次報(bào)道【Bull. Chem. Soc. Jpn. 1986, 59, 179】,。此反應(yīng)不是一個(gè)很常用的反應(yīng),底物胺只能是伯胺,,Ts腙也只能是α,α-二氯對(duì)甲苯磺酰腙,,這些都限制了其廣泛應(yīng)用。原始的反應(yīng)條件是兩種底物在醇類溶劑中反應(yīng),,但是底物胺需要過量,,后來B. Westermann等人發(fā)現(xiàn)加入二異丙基乙胺可以將底物胺減少到一個(gè)當(dāng)量。

此反應(yīng)相比傳統(tǒng)的疊氮化物-炔環(huán)加成反應(yīng)而言,,此反應(yīng)無需疊氮化合物及金屬鹽,原料廉價(jià)易得環(huán)境友好,,更加安全,,更加適合工藝生產(chǎn)。目前,,該反應(yīng)已經(jīng)逐漸應(yīng)用于各類天然產(chǎn)物的化學(xué)選擇性修飾與部分生物活性分子的合成,。早在2010年,Roger Hanselmann等人就報(bào)道了利用此反應(yīng)進(jìn)行公斤級(jí)反應(yīng)用于合成macrolide的重要中間體,。

圖片

反應(yīng)機(jī)理

圖片

反應(yīng)實(shí)例

圖片

(1-{(1S,2R)-2-[4-(2-Aminopyrimidin-5-yl)-phenyl]-1-fluoromethyl-2-methoxy-ethyl}-1H-[1,2,3]triazol-4-yl)-acetic Acid Ethyl Ester, 17. To a suspension of 11 (3.2 kg, 9.16 mol) in ethanol (11.2 L) was added N,N-diisopropylethylamine (9.9 L,56.8 mol) within 30 min at 0-15 °C. A solution of 10 (4.42kg, 12.1 mol) in MeCN (4.8 kg) was added over 1.5 h at below25 °C. The reaction was held at 20-25 °C for 1 h and thenwarmed to 35 °C and held for 8 h. The reaction mixture wassplit into three parts, and each was diluted with ethyl acetate(9.5 L). Each portion was cooled to 0-5 °C and extracted with1 M HCl (3 × 7.8 L). The combined aqueous extracts werebasified to pH 11 with 50% aqueous NaOH solution (2 kg) at0-5 °C. The cold aqueous solution was extracted with ethylacetate (2 × 9.5 L), and the combined organic extracts wereevaporated. The oil from all three workup portions werecombined, taken up in ethanol (16 L), and concentrated on arotary evaporator, yielding 17 (5.88 kg containing 2.84 kg ethanol, 80%) as an oil. An analytical sample was obtained by crystallizing the dry residue from ethyl acetate.

Org. Process Res. Dev. 2010, 14, 152–158】

    本站是提供個(gè)人知識(shí)管理的網(wǎng)絡(luò)存儲(chǔ)空間,,所有內(nèi)容均由用戶發(fā)布,,不代表本站觀點(diǎn)。請(qǐng)注意甄別內(nèi)容中的聯(lián)系方式,、誘導(dǎo)購(gòu)買等信息,,謹(jǐn)防詐騙。如發(fā)現(xiàn)有害或侵權(quán)內(nèi)容,,請(qǐng)點(diǎn)擊一鍵舉報(bào),。
    轉(zhuǎn)藏 分享 獻(xiàn)花(0

    0條評(píng)論

    發(fā)表

    請(qǐng)遵守用戶 評(píng)論公約

    類似文章 更多