三氯乙酸催化合成β-烯胺酮类化合物
2014-07-04李江飞王永秋
袁 慰,李江飞,肖 兰,王永秋
(淮北师范大学 化学与材料科学学院,安徽 淮北 235000)
从广义上讲,β-烯胺酮就是指结构中含有N—C=C—C=O 的化合物,也被称为β-氨基-α,β-不饱和酮或烯胺基酮[1].β-烯胺酮具有共轭结构,使其既具有烯胺的亲核性,又具有烯酮的亲电性.正是由于该物理化学性质不同于一般的酮,所以β-烯胺酮是十分重要的有机合成中间体,常被应用于药物合成,如抗菌药物的合成[2],抗癌药物的研发[3],抗痉挛药物的合成[4]等.除此之外,β-烯胺酮也常被应用于合成杂环化合物,如喹啉[5],四氢苯并噁嗪酮[6],吡啶酮[7]等.因此合成β-烯胺酮具有现实意义.早在20世纪,Martin[8]研究用β-二羰基化合物与胺反应可以合成β-烯胺酮.近几年,探索有效的催化体系称为研究热点.根据文献报道常用催化剂有 Yb(OTf)3[9]、Zn(ClO4)2·6H2O[10]、ZrCl4[11]、Bi(TFA)3[12]等,但是大多数催化剂都有不足之处,反应原料价格昂贵、反应条件苛刻、产率不高等.
本文采用三氯乙酸作为催化剂,廉价且易获取,操作简单,反应条件温和,是一种绿色催化剂.在三氯乙酸条件下催化β-二酮和芳胺类化合物,合成β-烯胺酮.反应路线如下:
1 实验部分
1.1 仪器和试剂
WPS-1 型数字熔点仪( 温度计未校正);TLC 进行跟踪反应;Bruker 核磁共振仪(TMS 为内标,400 Hz);PE-2400 型元素自动分析仪;三氯乙酸,所用试剂均为AR级.
1.2 β–烯胺酮类化合物合成步骤
1.2.1 化合物3a的合成
在25 mL的圆底烧瓶中,加入乙酰丙酮0.3 g(3 mmol)、对甲苯胺0.321 g(3 mmol)、三氯乙酸0.2 g、乙醇10 mL,室温搅拌,TLC跟踪反应.反应结束后抽滤,取滤液,向滤液中加入适量水,冷却结晶.待结晶析出后,减压抽滤,滤饼干燥得β–烯胺酮类化合物3a.
采用上述合成方法,换用不同的R1和R2分别进行室温反应,可得到一系列相关产物.
2 化合物的结构和表征
合成一系列β–烯胺酮类化合物,详见表1.
表1 三氯乙酸催化合成β-烯胺酮类化合物
3a[13],黄色固体,产率95%,熔点66-67 °C.1H NMR(400 MHz,CDCl3)δ 12.40(s,1H),7.05-7.23(m,4H),5.17(s,1H),2.34(s,3H),2.08(s,3H),1.96(s,3H).13C NMR(100 MHz,CDCl3)δ 195.75,160.50,135.99,135.35,129.53,124.74,97.08,77.24,76.92,76.60,28.96,20.75,19.59.Anal.calcd for C,76.16;H,7.99;N,7.40;found C,76.13;H,7.95;N,7.42.
3b[13],黄色固体,产率 92%,熔点 60-61 °C.1H NMR(400 MHz,CDCl3)δ 12.42(s,1H),7.32-7.16(m,4H),5.20(s,1H),2.09(s,3H),1.97(s,3H).13C NMR(100 MHz,CDCl3)δ 189.23,159.55,137.27,130.85,129.09,125.73,125.72,98.00,79.89,29.11,19.65.Anal.calcd for C,63.01;H,5.77;N,6.68;found C,63.00;H,5.75;N,6.65.
3c[13],黄色固体,产率86%,熔点48-49 °C.1H NMR(400 MHz,CDCl3)δ 12.49(s,1H),7.45-7.03(m,5H),5.20(s,1H),2.08(s,3H),2.00(s,3H).13C NMR(100 MHz,CDCl3)δ 189.13,160.13,138.63,128.98,125.45,124.66,97.49,29.08,19.74.Anal.calcd for C,75.40;H,7.48;N,7.99;found C,75.42;H,7.45;N,7.97;
3d,黄色固体,产率89%,熔点193-194 °C.1H NMR(400 MHz,DMSO)δ 12.12(s,1H),9.86(s,1H),7.23-6.66(m,4H),5.13(s,1H),1.95(s,6H).13C NMR(100 MHz,DMSO)δ 194.57,160.36,150.75,126.50,125.41,119.41,116.15,97.51,40.55 40.34,40.13,39.84,39.72,39.40,39.29,29.20,19.80.Anal.calcd for C,69.09;H,6.85;N,7.32;found C,69.06;H,6.86;N,7.30.
3e,黄色液体,产率93%.1H NMR(400 MHz,CDCl3)δ 10.78(s,1H),5.07-4.70(m,1H),3.25-2.93(m,2H),2.01-1.80(m,6H),1.50(m,2H),1.01-0.77(m,3H).13C NMR(101 MHz,CDCl3)δ 194.30,163.02,94.80,23.17,11.15.Anal.calcd for C,68.04;H,10.71;N,9.92;found C,68.05;H,10.70;N,9.90.
3f[14],黄色固体,产率95%,熔点90-91 °C.1H NMR(400 MHz,CDCl3)δ 13.04(s,1H),7.87-7.41(m,5H),7.21-7.05(m,4H),5.89(s,1H),2.37(s,3H),2.13(s,3H).13C NMR(100 MHz,CDCl3)δ 188.38,162.45,140.03,129.62,126.92,124.74,93.78,20.81,20.22.Anal.calcd for C,81.24;H,6.82;N,5.57;found C,81.23;H,6.84;N,5.55.
3g,黄色固体,产率93%,熔点156-157 °C.1H NMR(400 MHz,CDCl3)δ 13.00(s,1H),8.76(s,1H),7.90-7.32(m,5H),7.32-6.60(m,4H),5.89(s,1H),2.16(s,3H).13C NMR(100 MHz,CDCl3)δ 188.95,131.03,129.95,128.34,127.01,116.54,111.78,94.36,20.31.Anal.calcd for C,75.87;H,5.97;N,5.53;found C,75.89;H,5.95;N,5.54.
3h[9],黄色固体,产率86%,熔点178-180 °C.1H NMR(400 MHz,CDCl3)δ 7.38-7.15(m,5H),6.93(s,1H),5.56(s,1H),2.51(t,J=6.1 Hz,2H),2.34(t,J=6.4 Hz,2H),2.06-1.96(m,2H).13C NMR(100 MHz,CDCl3)δ 198.22,162.34,138.05,129.19,125.39,123.82,99.55,36.39,29.59,21.74.Anal.calcd for C,76.98;H,7.00;N,7.48;found C,76.97;H,7.03;N,7.47.
3i[14],黄色固体,产率89%,熔点192-191 °C.1H NMR(400 MHz,CDCl3)δ 7.36-7.07(m,4H),5.48(s,1H),2.50(t,J=6.0 Hz,2H),2.33(t,J=6.4 Hz,2H),2.01(m,2H).13C NMR(100 MHz,CDCl3)δ 198.28,162.24,136.68,130.63,129.29,125.03,99.72,36.38,29.48,21.68.Anal.calcd for C,65.02;H,5.46;Cl,15.99;N,6.32;found C,65.00;H,5.47;N,6.33.
3j,黄色固体,产率88%,熔点127-128 °C.1H NMR(400 MHz,CDCl3)δ 7.38-6.80(m,4H),6.39(s,1H),5.70(s,1H),3.83(s,3H),2.52(t,J=6.0 Hz,2H),2.35(t,J=6.3 Hz,2H),2.03(m,2H).13C NMR(100 MHz,CDCl3)δ 198.25,160.92,127.32,125.13,123.02,120.54,110.91,100.25,55.51,36.39,30.01,21.74.Anal.calcd for C,71.87;H,6.96;N,6.45;found C,71.89;H,6.95;N,6.43.
3k,黄色固体,产率91%,熔点180-181 °C.1H NMR(400 MHz,Acetone)δ 7.15(t,J=8.0 Hz,1H),6.76(s,1H),6.64(m,2H),5.60(s,1H),2.57(t,J=6.1 Hz,2H),2.25(t,J=6.4 Hz,2H),2.03-1.89(m,2H).13C NMR(100 MHz,CDCl3)δ 202.30,167.37,163.31,145.32,134.97,118.91,116.79,114.92,103.88,41.36,26.86,4.25.Anal.calcd for C,70.92;H,6.45;N,6.89;found C,70.90;H,6.46;N,6.87.
3l[14],黄色固体,产率93%,熔点198-199 °C.1H NMR(400 MHz,CDCl3)δ 7.19-7.08(m,4H),6.50(s,1H),5.51(s,1H),2.33(s,5H),2.19(s,2H),1.09(s,6H).13C NMR(100MHz,CDCl3)δ 197.60,160.70,135.44,135.32,129.73,123.95,98.21,50.25,43.39,32.70,28.20,20.79.Anal.calcd for C,78.56;H,8.35;N,6.11;found C,78.52;H,8.36;N,6.14.
3m[14],黄色固体,产率88%,熔点208-209 °C.1H NMR(400 MHz,CDCl3)δ 7.37-7.04(m,4H),6.44(s,1H),5.52(s,1H),2.34(s,2H),2.22(s,2H),1.11(s,6H).13C NMR(100 MHz,CDCl3)δ 198.45,136.69,129.35,124.94,98.96,50.24,43.43,32.72,28.19.Anal.calcd for C,67.33;H,6.46;N,5.61;found C,67.35;H,6.45;N,5.63.
3n[14],黄色固体,产率90%,熔点184-185 °C.1H NMR(400 MHz,CDCl3)δ 7.38-7.04(m,5H),6.90(s,1H),5.57(s,1H),2.35(s,2H),2.20(s,2H),1.08(s,6H).13C NMR(100 MHz,CDCl3)δ 197.23,138.17,129.18,125.34,123.75,98.29,50.25,43.37,32.70,28.19.Anal.calcd for C,78.10;H,7.96;N,6.51;found C,78.12;H,7.92;N,6.52.
3o,黄色固体,产率89%,熔点240-241 °C.1H NMR(400 MHz,DMSO)δ 9.54(s,1H),8.69(s,1H),7.27-6.77(m,4H),5.37(s,1H),2.35(s,2H),2.04(s,2H),1.00(s,6H).13C NMR(100 MHz,DMSO)δ 195.81,160.22,158.30,140.62,130.20,113.72,111.74,109.91,97.41,42.47,32.58,28.29.Anal.calcd for C,72.70;H,7.41;N,6.06;found C,72.73;H,7.40;N,6.07.
3p,黄色固体,产率91%,熔点130-131 °C.1H NMR(400 MHz,CDCl3)δ 7.45-6.85(m,4H),6.23(s,1H),5.76(s,1H),3.86(s,3H),2.38(s,2H),2.25(s,2H),1.13(s,6H).13C NMR(100 MHz,CDCl3)δ 197.99,158.72,150.50,127.55,124.91,122.56,120.60,110.82,99.24,55.53,50.24,43.96,32.69,28.23.Anal.calcd for C,78.56;H,8.35;N,6.11;found C,78.55;H,8.33;N,6.10.
3 结论
总之,虽然合成β–烯胺酮类化合物的方法有很多种,但是我们采用三氯乙酸作为催化剂合成目标产物,反应条件温和,产率较高,得到一条合成β–烯胺酮类化合物的有效方法.
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