毛澤偉,姜 圓,饒高雄
(云南中醫(yī)學(xué)院藥學(xué)院,云南昆明650500)
苯并呋喃類化合物廣泛存在于多種藥用植物中,具有多種生理活性而備受關(guān)注,如抗腫瘤、抗菌、抗真菌、抗氧化等[1-5].目前國內(nèi)外對苯并呋喃化合物的衍生化進(jìn)行了大量的研究[6-10],豐富了人們對該類化合物的認(rèn)識.酚類化合物具有良好的殺菌和抗氧化活性,我們將酚與苯并呋喃連接起來,希望得到具有新型結(jié)構(gòu)和進(jìn)一步研究價值的化合物.
以水楊醛與2-溴-4’-氟苯乙酮為原料出發(fā),經(jīng)取代、環(huán)合反應(yīng)生成2-(4-氟苯甲?;?苯并呋喃,再與酚類化合物反應(yīng),合成得到6個新的苯基醚類苯并呋喃衍生物(2a~2f),并通過IR和NMR對其結(jié)構(gòu)進(jìn)行表征.
Bruker AM-300核磁共振波譜儀,TMS為內(nèi)標(biāo);Bio-Rad FTS-135紅外光譜儀,KBr壓片;YANACO顯微熔點儀.化學(xué)試劑均購自韶遠(yuǎn)化學(xué)科技(上海)有限公司;無水N,N-二甲基甲酰胺是經(jīng)加入鈣氫回流后減壓蒸餾獲得;石油醚、二氯甲烷和乙酸乙酯等均為市售分析純.
目標(biāo)化合物的合成路線如圖1所示.
1.2.1 中間體2 -(4-氟苯甲?;?苯并呋喃(1)的合成[11]
稱取2.44 g(20 mmol)水楊醛和5.52 g(40 mmol)K2CO3于100 mL圓底燒瓶中,加入60 mL丙酮,在室溫攪拌下分批加入4.34 g(20 mmol)2-溴-4’-氟苯乙酮,并加熱回流反應(yīng)4 h.TLC檢測反應(yīng)完成后,冷卻至室溫,真空濃縮.向反應(yīng)瓶中加入80 mL水?dāng)嚢?0 min,抽濾,固體依次用20 mL 10%KOH溶液、水(20 mL×3)洗滌,干燥,得到黃褐色固體4.08 g,收率85%.m.p.188.4 ~190.6 ℃;1H NMR(300 MHz,CDCl3)δ:8.10 ~8.15(dd,J=5.7 Hz,5.4 Hz,2H),7.74(d,J=7.8 Hz,1H),7.65(d,J=8.7 Hz,1H),7.55(s,1H),7.51(d,J=7.8 Hz,1H),7.32 ~7.37(dd,J=7.8 Hz,7.2 Hz,1H),7.19 ~ 7.26(dd,J=5.1 Hz,8.7 Hz,1H);13C NMR(75 MHz,CDCl3)δ:182.75,164.00,155.97,152.14,133.37,132.25,132.13,128.49,126.92,124.10,123.35,116.40,115.93,115.64,112.56.
1.2.2 苯基醚類苯并呋喃類似物(2)的合成
目標(biāo)化合物的一般合成方法[12]:依次稱取240 mg(1 mmol)化合物1、276 mg(2 mmol)K2CO3和酚(2 mmol)于25 mL圓底燒瓶中,加入10 mL無水DMF溶解,并置于130℃反應(yīng)3~5 h.TLC檢測反應(yīng)完成后,冷卻至室溫,將反應(yīng)物倒入20 mL水中,并用DCM萃取(10 mL×3).有機(jī)相經(jīng)無水硫酸鈉干燥后濃縮,殘余物以V(石油醚)∶V(乙酸乙酯)=30∶1為洗脫劑進(jìn)行柱層析.
化合物2a:淡黃色粘稠油狀,收率83%.1H NMR(300 MHz,CDCl3)δ:8.10(d,J=8.7 Hz,2H),7.72(d,J=7.8 Hz,1H),7.62(d,J=8.4 Hz,1H),7.39 ~7.51(m,4H),7.01 ~7.07(dd,J=9.0 Hz,J=8.4 Hz,4H),6.92(d,J=8.7 Hz,2H);13C NMR(75 MHz,CDCl3)δ:182.72,161.86,156.12,152.33,141.04,132.05,128.08,127.91,124.39,123.01,121.98,120.75,118.18,115.52,114.72,112.32;IR(KBr)ν:3 432,3 108,1 662,1 611,1 521,1 473,1 454,1 288,1 109,1 047,970,753 cm-1.
化合物 2b:淡黃色固體,收率77%.m.p.195.7 ~197.8 ℃;1H NMR(300 MHz,CDCl3)δ:8.10(d,J=8.7 Hz,2 H),7.73(d,J=7.8 Hz,1H),7.64(d,J=8.4 Hz,1H),7.53(s,1H),7.48(t,J=7.2 Hz,1H),7.34(t,J=7.2 Hz,1H),7.07(t,J=9.0 Hz,4H),6.96(d,J=9.0 Hz,2H),3.83(s,3 H);13C NMR(75 MHz,CDCl3)δ:182.77,163.03,156.80,155.87,152.65,148.50,131.91,131.02,128.10,127.04,123.91,123.17,121.74,116.46,115.64,115.15,112.48,55.67;IR(KBr)ν:3 426,3 110,1 669,1 620,1 533,1 468,1 445,1 412,1 266,1 109,1 052,968,755 cm-1.
化合物 2c:淡綠色粘稠油狀,收率 72%.1H NMR(300 MHz,CDCl3)δ:8.11(d,J=8.7 Hz,2 H),7.74(d,J=7.8 Hz,1H),7.65(d,J=8.4 Hz,1H),7.50(s,1H),7.25 ~ 7.36(m,4 H),6.96 ~ 7.11(m,4H),2.20(s,3H);13C NMR(75 MHz,CDCl3)δ:182.38,162.97,156.74,155.21,152.09,145.23,132.01,128.81,127.55,123.13,123.06,121.68,120.37,116.31,115.22,112.32,31.07;IR(KBr)ν:3 431,2 931,1 650,1 603,1 551,1 521,1 468,1 412,1 366,1 301,1 272,1 169,1 135,961,754 cm-1.
化合物2d:白色固體,收率 56%.m.p.193.6 ~195.3 ℃;1H NMR(300 MHz,CDCl3)δ:8.13(d,J=8.7 Hz,2 H),7.72(d,J=7.8 Hz,1H),7.66(d,J=8.0 Hz,1H),7.60(d,J=7.8 Hz,1H),7.39(d,J=8.0 Hz,2H),7.21 ~7.32(m,2 H),6.99 ~7.11(m,4 H);13C NMR(75 MHz,CDCl3)δ:182.32,161.67,155.96,154.12,152.47,139.50,132.05,130.14,129.90,129.47,128.32,126.99,125.52,122.49,117.45,116.07,112.51;IR(KBr)ν:3 432,1 663,1 587,1 524,1 497,1 464,1 421,1 390,1 232,1 185,1 123,970,750 cm-1.
化合物 2e:淡黃色粘稠油狀,收率 69% .1H NMR(300 MHz,CDCl3)δ:8.10(d,J=8.7 Hz,2H),7.73(d,J=7.8 Hz,1H),7.63(d,J=8.0 Hz,1H),7.51(s,1H),7.22 ~7.34(m,3H),6.92 ~7.01(m,4H),2.22(s,6H);13C NMR(75 MHz,CDCl3)δ:182.27,162.78,156.23,155.01,153.13,145.74,132.18,128.81,127.55,123.13,122.86,121.61,120.23,116.32,112.11,31.12;IR(KBr)ν:3 433,2 942,1 656,1 621,1 567,1 512,1 469,1 422,1 389,1 311,1 282,1 215,1 156,1 101,970,756 cm-1.
化合物 2f:淡紅色粘稠油狀,收率 86%.1H NMR(300 MHz,CDCl3)δ:8.03(d,J=8.7 Hz,2H),7.73(d,J=7.8 Hz,1H),7.62(d,J=7.8 Hz,1H),7.26 ~7.41(m,8 H),7.24(d,J=7.8 Hz,2H),6.93 ~7.00(m,4 H);13C NMR(75 MHz,CDCl3)δ:182.83,162.37,155.89,152.51,151.89,137.23,134.73,131.88,131.04,130.27,129.24,128.27,128.16,127.50,127.04,125.58,123.94,123.20,121.71,116.70,115.88,112.50;IR(KBr)ν:3 431,2 980,1 657,1 631,1 577,1 537,1 489,1 432,1 412,1 367,1 341,1 292,1 253,1 181,1 102,970,829,756 cm-1.
在苯基醚類苯并呋喃衍生物的合成中,考察了溫度和反應(yīng)時間對反應(yīng)收率的影響,并對反應(yīng)條件進(jìn)行了優(yōu)化,結(jié)果見表1.
表1 反應(yīng)條件優(yōu)化
從表1可以看出,在130℃反應(yīng)3~5 h效果最好,升高溫度或延長反應(yīng)時間均會增加副產(chǎn)物的生成.另外,利用目標(biāo)化合物在二氯甲烷中溶解性較好,而其它雜質(zhì)的溶解性較差的特點,采用二氯甲烷萃取時,減少了雜質(zhì)的量,有效簡化了分離過程.
文中建立了一種簡便的合成苯基醚類苯并呋喃衍生物的方法,后續(xù)生物活性研究正在進(jìn)行中.酚基團(tuán)的引入可能會提高苯并呋喃類化合物的生物活性,這為開展該類化合物的衍生化研究提供了一個新的思路.
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