陸 軍,李新生
(1.蘇州百靈威超精細(xì)材料技術(shù)有限公司,江蘇 蘇州 215129;2.浙江師范大學(xué) 化學(xué)與生命科學(xué)學(xué)院,浙江 金華 321004)
近期,固體催化劑鎢磺酸以其廉價(jià)易得(見反應(yīng)式1)、無毒及對水和空氣比較穩(wěn)定等特點(diǎn)而受到人們的重視,并應(yīng)用于多種有機(jī)合成反應(yīng)中,獲得了良好的效果[7].基于文獻(xiàn)[8]對固體酸催化劑在有機(jī)合成方面的研究,本實(shí)驗(yàn)把鎢磺酸應(yīng)用于Strecker 反應(yīng)(見反應(yīng)式2)來合成α-胺基腈化合物,獲得了良好的結(jié)果.
1H NMR 在Bruker AMX 400 核磁共振儀上測定,以CDCl3為溶劑,四甲基硅烷(TMS)為內(nèi)標(biāo);高分辨質(zhì)譜(HRMS)在VG 7035 質(zhì)譜儀上測定;紅外光譜(IR)采用液膜或壓片法,在Bio-Rad FTS 165 型紅外光譜儀上測定.
所用試劑均為市售分析純、化學(xué)純或工業(yè)級藥品.所用溶劑都經(jīng)過干燥和重蒸.
在100 mL 圓底燒瓶中加入氯磺酸(11.6 g,0.1 mol),冰水冷卻下慢慢分批加入無水鎢酸鈉(14.7 g,0.05 mol),振蕩1 h,加入30 mL 乙醚攪拌均勻,濃縮,重復(fù)2 次以除盡氯化氫氣體,得產(chǎn)物.
在10 mL 圓底燒瓶中加入自制鎢磺酸(0.3 g)和二氯甲烷(5 mL),室溫?cái)嚢柘录尤肴?1 mmol)和胺(1 mmol),隨后加入三甲基氰硅烷(TMSCN,1.1 mmol),室溫?cái)嚢?實(shí)驗(yàn)過程中通過硅膠薄層色譜(TLC)跟蹤,用紫外燈檢測.反應(yīng)完全后抽濾,固體用二氯甲烷洗滌,有機(jī)層用飽和食鹽水洗滌,然后用無水硫酸鈉干燥,減壓蒸去溶劑,剩余物柱色譜提純,得到產(chǎn)物.
在鎢磺酸的催化作用下,不同取代基的醛和胺在室溫下都能順利地進(jìn)行Strecker 反應(yīng)(見表1).當(dāng)醛的苯環(huán)上有吸電子基時,反應(yīng)產(chǎn)率稍微增加,反之則減少(見表1 項(xiàng)目1~7);當(dāng)芳環(huán)為呋喃和噻吩時,產(chǎn)率降低很多(見表1 項(xiàng)目9~10).該反應(yīng)在此反應(yīng)條件下無副產(chǎn)物產(chǎn)生,可能是由于在鎢磺酸的催化作用下,醛和胺能夠快速形成亞胺,而亞胺又能夠被鎢磺酸活化而進(jìn)行Strecker 反應(yīng).鎢磺酸具有無毒及對水和空氣穩(wěn)定的優(yōu)點(diǎn),同時,它能夠被回收使用,其催化活性循環(huán)使用3 次均保持不變,避免了
在反應(yīng)中使用毒害性大的催化劑,使反應(yīng)環(huán)境友好.
表1 鎢磺酸催化的α-胺基腈化合物的合成
3a IR(KBr)σ/cm-1:3 370,2 236,1 606,1 488.1H NMR(400 MHz,CDCl3)δ/ppm:4.02(d,J=8.4 Hz,1H),5.41(d,J=8.4 Hz,1H),6.74(d,J=7.8 Hz,2H),6.92(d,J=7.8 Hz,1H),7.29~7.25(m,2H),7.48~7.40(m,3H),7.69~7.58(m,2H).HRMS 計(jì)算值:C14H12N2,208.100 0;文獻(xiàn)值:208.100 2.
3b IR(KBr)σ/cm-1:3 332,2 228.1H NMR(400 MHz,CDCl3)δ/ppm:1.83(br,s,1H,NH),3.95(q,J=14.85 Hz,2H),4.69(s,1H),7.27~7.51(m,10H).HRMS 計(jì)算值:C15H14N2,222.115 7;文獻(xiàn)值:222.116 3.
3c IR(KBr)σ/cm-1:2 228.1H NMR(400 MHz,CDCl3)δ/ppm:1.82(m,4H),2.64(m,4H),5.04(s,1H),7.34~7.53(m,5H).HRMS 計(jì)算值:C12H14N2,186.115 7;文獻(xiàn)值:186.115 3.
3d IR(KBr)σ/cm-1:2 231.1H NMR(400 MHz,CDCl3)δ/ppm:2.57(t,J=4.62 Hz,4H),3.72(t,J=4.62 Hz,4H),4.81(s,1H),7.37~7.54(m,5H).HRMS 計(jì)算值:C12H14N2O,202.110 6;文獻(xiàn)值:202.109 7.
3e IR(KBr)σ/cm-1:3 338,2 236;1H NMR(400 MHz,CDCl3)δ/ppm:2.45(s,3H),4.15(d,J=8.04 Hz,1H),5.40(d,J=8.01 Hz,1H),6.81(d,J=8.43 Hz,2H),6.95(m,1H),7.28~7.35(m,4H),7.51(d,J=8.04 Hz,2H).HRMS 計(jì)算值:C15H14N2,222.115 7;文獻(xiàn)值:222.116 1.
3f IR(KBr)σ/cm-1:3 360,2 235;1H NMR(400 MHz,CDCl3)δ/ppm:3.84(s,3H),4.15(d,J=8.43 Hz,1H),5.36(d,J=8.04 Hz,1H),6.79(d,J=8.43 Hz,2H),6.90~6.99(m,3H),7.29(t,J=8.03 Hz,2H),7.50(d,J=8.01 Hz,2H).HRMS 計(jì)算值:C15H14N2O,238.110 6;文獻(xiàn)值:238.110 2.
3g IR(KBr)σ/cm-1:3 382,2 238;1H NMR(400 MHz,CDCl3)δ/ppm:4.10(d,J=8.43 Hz,1H),5.36(d,J=8.43 Hz,1H),6.72(d,J=7.65 Hz,2H),6.88(t,J=7.43 Hz,1H),7.24(t,J=7.83 Hz,2H),7.37(d,J=8.43 Hz,2H),7.47(d,J=8.22 Hz,2H).HRMS 計(jì)算值:C14H11ClN2,242.061 1;文獻(xiàn)值:242.060 5.
3h IR(KBr)σ/cm-1:3 429,2 232;1H NMR(400 MHz,CDCl3)δ/ppm:3.91(d,J=9.24 Hz,1H),5.04(m,1H),6.25(dd,J=16.05 Hz,J=5.22 Hz,1H),6.76(q,J=3.21 Hz,2H),6.89(t,J=7.43 Hz,1H),7.03(dd,J=15.63 Hz,J=1.59 Hz,1H),7.23~7.39(m,7H).HRMS 計(jì)算值:C16H14N2,234.115 7;文獻(xiàn)值:234.115 5.
3i IR(KBr)σ/cm-1:3 423,2 241;1H NMR(400 MHz,CDCl3)δ/ppm:2.33(s,3H),4.21(d,J=8.82 Hz,1H),5.43(d,J=8.85 Hz,1H),6.01(q,J=1.07 Hz,1H),6.46(d,J=2.82 Hz,1H),6.79(d,J=8.43 Hz,2H),6.92(m,1H),7.29(m,2H).HRMS 計(jì)算值:C13H12N2O,212.095 0;文獻(xiàn)值:212.095 2.
3j IR(KBr)σ/cm-1:3 338,2 235;1H NMR(400 MHz,CDCl3)δ/ppm:4.20(d,J=8.85 Hz,1H),5.58(d,J=9.24 Hz,1H),6.74(d,J=7.62 Hz,2H),6.89(t,J=7.43 Hz,1H),7.00(q,J=2.81 Hz,1H),7.21~7.33(m,4H).HRMS 計(jì)算值:C12H10N2S,214.056 5;文獻(xiàn)值:214.056 3.
3k IR(KBr)σ/cm-1:3 315,2 238,1 596,1 466;1H NMR(400 MHz,CDCl3)δ/ppm:7.49(d,J=8.4 Hz,2H),7.39~7.28(m,7H),4.73(s,1H),3.99(AB q,J=12.8 Hz,2H).HRMS 計(jì)算值:C15H13ClN2,256.076 7;文獻(xiàn)值:256.076 2.
3l IR(KBr)σ/cm-1:3 325,3 031,2 923,2 231,1 598,1 491;1H NMR(400 MHz,CDCl3)δ/ppm:1.83(s,1H),3.82(s,3H),4.00(AB q,J=12.8 Hz,2H),4.70(s,1H),6.92(d,J=8.4 Hz,2H),7.41~7.29(m,5H),7.44(d,J=8.8 Hz,2H).HRMS 計(jì)算值:C16H16N2O,252.126 3;文獻(xiàn)值:252.125 9.
3m IR(KBr)σ/cm-1:3 307,3 064,2 238,1 595,1 490;1H NMR(400 MHz,CDCl3)δ/ppm:4.05(d,J=8.4 Hz,1H),5.38(d,J=8.4 Hz,1H),6.69(d,J=9.2 Hz,2H),7.23(d,J=8.4 Hz,2H),7.44(d,J=8.4 Hz,2H),7.54(d,J=8.8 Hz,2H).HRMS 計(jì)算值:C14H10Cl2N2,276.022 1;文獻(xiàn)值:276.021 8.
3n IR(KBr)σ/cm-1:3 336,2 234;1H NMR(400 MHz,CDCl3)δ/ppm:4.25(d,J=8.43 Hz,1H,NH),5.38(d,J=8.43 Hz,1H,CH),6.69(d,J=8.43 Hz,2H,CH2),7.21(d,J=8.85 Hz,2H,CH2),7.44~7.58(m,5H).HRMS 計(jì)算值:C14H11ClN2,242.061 1;文獻(xiàn)值:242.060 6.
3o IR(KBr)σ/cm-1:3 328,3 033,2 236,1 596,1 495;1H NMR(400 MHz,CDCl3)δ/ppm:3.84(s,3H),4.00(d,J=7.6 Hz,1H),5.31(d,J=7.6 Hz,1H),6.69(d,J=8.8 Hz,2H),6.97(d,J=8.4 Hz,2H),7.22(d,J=8.8 Hz,2H),7.49(d,J=8.8 Hz,2H).HRMS 計(jì)算值:C15H13ClN2O,272.071 6;文獻(xiàn)值:272.071 4.
鎢磺酸能有效地催化醛、胺和三甲基氰硅烷間的三組分Strecker 反應(yīng),且反應(yīng)條件溫和、操作簡單、催化劑可循環(huán)使用,是一鍋法合成α-氰基化合物的簡單有效的方法.
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