吳運(yùn)軍,邵 敏,馮志君,汪美芳,王少印
胍類化合物作為有機(jī)堿在生理環(huán)境中處于完全質(zhì)子化狀態(tài),保持正電性,易于在配基與受體及酶與底物間通過氫鍵或靜電作用形成特殊的相互作用[1]。許多有生物活性的天然化合物、合成化合物中都含有胍基官能團(tuán),胍基上的氮親和性和氫原子對(duì)碳酸酯、磷酸酯和肽有高度的親和性,容易形成具有幾何構(gòu)型的氫鍵結(jié)構(gòu)[2];而氨基和各種酸能生成水溶性的鹽,所以含有胍基的藥物不但容易在體內(nèi)輸送,而且使吸收、滲透更具有選擇性,進(jìn)而可以在體內(nèi)產(chǎn)生抗炎癥作用、交感神經(jīng)刺激或抑制作用、抗組胺作用、降壓作用、降血糖作用等生理功能[3],因此胍基是藥物設(shè)計(jì)和藥物分子結(jié)構(gòu)改造的首選基團(tuán)之一。設(shè)計(jì)新的胍類化合物、研究胍類化合物新的合成方法,一直是胍類化合物的研究的中心[4-5]。
胍類典型的合成方法是利用胺與親電的胍化試劑反應(yīng)而得到相應(yīng)的胍類化合物[6-8]。最新研究發(fā)現(xiàn)胍類化合物還可以通過不同的催化合成方法得到[9-16],其中一類二甲基硅基亞甲基橋聯(lián)雙胺基三價(jià)稀土金屬胺基配合物可以有效催化空間位阻不同的碳二亞胺與胺類發(fā)生加成反應(yīng),生成相應(yīng)的取代胍,提供了一種直接的、原子經(jīng)濟(jì)性的合成多取代胍的方法[14]。本文將該方法引入新型胍類化合物(1a-7b)的合成,產(chǎn)物結(jié)構(gòu)經(jīng)IR、1H NMR和13C NMR表征。
Shimadzu FT-IR-8400s 型 紅 外 光 譜 測(cè) 定 儀(KBr壓片);Bruker AV-300MHZ型超導(dǎo)核磁共振儀(TMS為內(nèi)標(biāo),CDCl3為溶劑);所用試劑均為國產(chǎn)分析純并經(jīng)除水純化處理;催化劑按文獻(xiàn)[17]方法合成。
按文獻(xiàn)[17]的優(yōu)化條件,在30mL的Schlenk試管反應(yīng)器中加入催化劑{(CH2SiMe2)[(2,6-iPr2C6H3)N]2}SmN(SiMe3)2(THF)(0.056g,0.069mmol)和溶劑 THF 5ml,待催化劑充分溶解后,加入 N,N'-二異丙基碳二亞胺(0.291g,2.31mmol)和3-甲基吡啶(0.215g,2.31mmol),室溫反應(yīng)6小時(shí)后,加水1ml終止反應(yīng),用二氯甲烷(3×10ml)提取有機(jī)相,加入無水硫酸鈉干燥后過濾,濾液減壓抽除有機(jī)溶劑即可得粗產(chǎn)物,經(jīng)用乙醚或THF重結(jié)晶可得到白色晶體0.518g,產(chǎn)率 82%。IR(neat cm-1)νg3372,3116,2974,2878,1297,1238,841,816,728;1H NMR(CDCl3,300MHz):δ(ppm)7.93(d,1H,J=5.3Hz),6.69(s,1H),6.43(d,1H,J=5.1Hz),3.92(m,2H),2.24(s,3H),1.31-1.23(br,12H);13CNMR(CDCl3,75.4MHz):δ(ppm)163.2,147.2,144.7,120.0,115.4,42.1,23.1,20.5。
用同樣方法合成(1b-7b),實(shí)驗(yàn)結(jié)果及表征數(shù)據(jù)如下:
1a:無色油狀物,產(chǎn)率:62%;IR(neat cm-1)ν1651,1368,1079,1041,813;1H NMR(CDCl3):δ(ppm)3.38(br,1H),3.25(br,1H),3.04(q,J=6.9Hz,4H),0.99(m,18H);13C NMR(CDCl3):δ(ppm)153.1,46.5,45.1,41.9,24.1,22.9,11.9;
1b:無色油狀物,產(chǎn)率:84%;IR(neat cm-1):ν1269,858,812,773,712;1H NMR(CDCl3):δ(ppm)3.04(q,J=7.2Hz,4H),2.85(br,1H),1.98-1.16(m,20H),0.96(t,J=7.2Hz,6H);13C NMR(CDCl3):δ(ppm)153.7,56.3,52.9,42.2,34.8,34.2,25.4,25.1,12.4;
2a:無色液體,產(chǎn)率:87%;IR(neat cm-1):ν1627,1382,1164,1091,1063,1013,762,704;1HNMR(CDCl3):δ(ppm)3.36(m,2H),3.24(m,4H),1.78(m,4H),1.07(m,12H);13C NMR(CDCl3):δ(ppm)153.1,47.3,46.0,24.6,24.1;
2b:白色固體,產(chǎn)率:83%;IR(neat cm-1):ν1602,1557,1380,1092,1080,1043,1022,816,758,712;1HNMR(CDCl3):δ(ppm)3.19(br,4 H),2.90(br,2H),1.74-1.18(m,24H);13C NMR(CDCl3):δ(ppm)153.1,54.4,47.5,34.8,25.4,25.2,24.8;
3a:無色液體,產(chǎn)率:88%;IR(neat cm-1):ν1631,1125,1071,1038,729;1H NMR(CDCl3):δ(ppm)3.31(m,2H),2.98(br,4H),1.47(br,6H),1.03(d,J=6.2Hz,12H);13C NMR(CDCl3):δ(ppm)154.7,48.7,46.6,45.7,25.7,24.7,24.4,23.3;
3b:白色固體,產(chǎn)率:85%;IR(neat cm-1):ν1586,1460,1383,1285,866,783,727;1H NMR(CDCl3):δ(ppm)2.96(br,4H),2.80(br,2H),1.83-0.96(m,26H);13CNMR (CDCl3):δ(ppm)155.5,55.9,53.0,48.6,34.8,34.0,25.8,25.4,25.1,24.8;
4a:白色固體,產(chǎn)率:73%;IR(neat,cm-1):ν1283,2960,2867,1649,1604,1379,1161,1121,1101,1034,814;1H NMR(CDCl3):δ(ppm)6.67(d,J=8.3Hz,1H),6.36(m,2H),3.72(s,3H),3.69(s,3H),1.08(d,J=6.1Hz,12H);13C NMR(CDCl3):δ(ppm)155.1,152.7,150.8,131.4,124.2,104.0,99.4,55.2,55.0,42.9,23.0;
4b:白 色 固 體,產(chǎn) 率:87%;IR(neat,cm-1):ν3378,3061,2959,1617,1375,1123,1041,829;1H NMR(CDCl3):δ(ppm)6.64(d,J=8.1Hz,1H),6.34(m,2H),3.68(s,3H),3.65(s,3H),3.34(br,2H),1.93-0.78(m,20H);13C NMR(CDCl3):δ(ppm)155.1,152.7,150.6,131.5,124.3,104.0,99.4,55.2,55.0,49.8,33.4,25.3,24.5;
5a:白色固體,產(chǎn)率:93%;IR(neat,cm-1):ν3383,2879,1664,1078,868,837;1HNMR(CDCl3):δ(ppm)6.74(s,4H),3.72(br,4H),1.12(d,J=5.9Hz,24H).13C NMR(CDCl3):δ(ppm)150.5,143.4,124.2,42.9,23.0;
5b:產(chǎn) 率:94%;IR(neat,cm-1):ν3410,2841,1572,1352,854,831,822,742;1H NMR(CDCl3):δ(ppm)6.69(s,4H),3.68(br,2H),3.32(br,4H),1.91-0.97(m,40H);13C NMR(CDCl3):δ(ppm)150.2,143.8,124.2,49.7,33.4,25.3,24.5;
6a:白色固體,產(chǎn)率:92%;IR(neat,cm-1):ν3379,2882,1668,1082,860,831;1H NMR(CDCl3):δ(ppm)8.03(d,J=7.7Hz,1H),7.74(d,J=7.2Hz,1H),7.37(m,4H),6.87(d,J=6.9Hz,1H),3.82(m,2H),3.58(br,2H),1.14(d,J=6.3Hz,12H).13C NMR(CDCl3):δ(ppm)149.7,146.2,134.5,129.3,127.4,126.1,125.4,124.4,124.0,121.2,117.6,43.0,23.1;
6b:白色固體,產(chǎn)率:93%;IR(neat,cm-1):ν3402,2838,1582,1362,858,837,820,734;1H NMR(CDCl3):δ(ppm)7.99(d,J=7.3Hz,1H),7.73(d,J=7.1Hz,1H),7.36(m,4H),6.88(d,J=6.2Hz,1H),3.69(br,2H),3.43(br,2H),1.99-0.82(m,20H);13C NMR(CDCl3):δ(ppm)149.4,146.5,134.5,129.4,127.4,126.1,125.4,124.4,124.1,121.1,117.6,49.9,33.6,25.4,24.7;
7b:白色 固體,產(chǎn)率:96%;IR(neat,cm-1)ν3337,2855,1451,1346,1298,1260,1238,1213,843,799,764;1H NMR(CDCl3,300MHz)δ(ppm)7.95(d,1H,J=5.2Hz),6.68(s,1H),6.47(d,1H,J=5.0Hz),3.60(m2H),2.22(s,3H),2.02-1.22(br,22H);13C NMR(CDCl3,75.4MHz)δ(ppm)150.8,144.1,140.7,126.0,118.2,48.0,30.2,24.2,23.8,20.0。
將稀 土 雙 胺 化 合 物 {(CH2SiMe2)[(2,6-iPr2C6H3)N]2}SmN(SiMe3)2(THF)應(yīng)用于胍類化合物的催化合成,以3%mol催化劑載入量和溫和的反應(yīng)條件(室溫,6小時(shí))得到(1a-7b)共14個(gè)新型胍類化合物,其中1a、1b、2a、2b、、3b分別由鏈狀脂肪仲胺和環(huán)狀脂肪仲胺與相應(yīng)的碳二亞胺反應(yīng)得到,由實(shí)驗(yàn)結(jié)果可見,在此催化體系中,脂肪仲胺可以順利胍化,產(chǎn)率83%(2b)到88%(3a),僅1a的產(chǎn)率較低(62%);取代苯胺、萘胺、芳香雙胺、雜環(huán)胺類胍化反應(yīng)比脂肪胺類容易,產(chǎn)率可高達(dá)87%(4b)到96%(7b),其中4a由于苯環(huán)上兩個(gè)給電子基CH3O-的影響,產(chǎn)率稍低(73%),以上結(jié)果與文獻(xiàn)[14]結(jié)果一致,拓展了該催化體系的應(yīng)用范圍,且催化效果良好。
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