李紹晨, 王燕燕, 方珊珊, 王 振, 徐 暉, 呂 敏
(西北農(nóng)林科技大學(xué) 植物保護(hù)學(xué)院,陜西 楊凌 712100)
朱砂葉螨Tetranychus cinnabarinusBoisduval廣泛分布于我國(guó)農(nóng)作物種植區(qū),是一種危害嚴(yán)重的植食性害螨,其具有生長(zhǎng)周期短、繁殖能力強(qiáng)、易產(chǎn)生抗藥性等特點(diǎn),是最難防治的有害生物之一[1-2]。目前,化學(xué)殺螨劑仍然是防治害螨發(fā)生的主要手段,但隨著人們食品安全及環(huán)境保護(hù)意識(shí)的提高,部分高毒殺螨劑 (如三氯殺螨醇) 已被禁止使用,并且長(zhǎng)時(shí)間使用一種殺螨劑,極易使害螨產(chǎn)生嚴(yán)重的抗藥性。螺螨酯和螺甲螨酯是拜耳公司研發(fā)的兩種殺螨劑。封云濤等用螺螨酯篩選山楂葉螨T.viennensis21 代,發(fā)現(xiàn)螺螨酯防治山楂葉螨存在抗性風(fēng)險(xiǎn),抗螺螨酯的山楂葉螨品系會(huì)產(chǎn)生交互抗性[3];螺甲螨酯對(duì)二斑葉螨T.urticae和加州新小綏螨Neoseiulus californicus生長(zhǎng)速率影響的試驗(yàn)表明,螺甲螨酯對(duì)捕食螨無(wú)害,但對(duì)葉螨有劇毒,可在10 d 內(nèi)實(shí)現(xiàn)種群抑制[4]。因此,研發(fā)高效、低毒、環(huán)境友好的新型殺螨劑已成為農(nóng)業(yè)發(fā)展亟待解決的問題。植物源天然產(chǎn)物因具有環(huán)境友好、作用方式獨(dú)特且不易產(chǎn)生抗藥性等特點(diǎn),已經(jīng)成為新農(nóng)藥研發(fā)的重要來(lái)源。
胡椒堿 (1,piperine,圖式1) 是從胡椒科植物中分離提取的一種桂皮酰胺類生物堿,具有廣泛的生物活性[5]。如在醫(yī)學(xué)領(lǐng)域,胡椒堿具有抗癌、消炎、抗癲癇等生物活性[6-7];在農(nóng)業(yè)領(lǐng)域,胡椒堿對(duì)多種農(nóng)業(yè)害蟲具有較好的生物活性[8-12]。因此,胡椒堿常作為先導(dǎo)化合物用于藥物研發(fā)。此外,噁二唑是一種含有氮原子和氧原子的五元雜環(huán),可通過(guò)多種非共價(jià)鍵與生物系統(tǒng)中的多種酶和受體結(jié)合,因此含有噁二唑雜環(huán)的衍生物一般具有多種生物活性[13]。例如,2-酰肼-1,3,4-噁二唑類化合物 (2,圖式1) 對(duì)多種病原菌具有抑制作用[14];Yang 等將1,3,4-噁二唑引入諾卡酮,得到一系列含噁二唑雜環(huán)的諾卡酮類化合物 (3,圖式1),其中部分化合物對(duì)小菜蛾3 齡幼蟲顯示出較好的殺蟲活性[15]。目前,商品化的含有噁二唑結(jié)構(gòu)的農(nóng)藥有殺蟲劑噁蟲酮(metoxadiazone)、除草劑噁草酮(oxadiazon)和殺線蟲劑tioxazafen 等?;诖?,本研究以胡椒堿為先導(dǎo)化合物,通過(guò)1,4-二溴丁烷橋接2-巰基-5-苯基-1,3,4-噁二唑雜環(huán)活性片段,合成一系列含1,3,4-噁二唑雜環(huán)的胡椒堿類衍生物,并評(píng)價(jià)其對(duì)朱砂葉螨T.cinnabarinus的觸殺活性。
圖式1 目標(biāo)化合物的設(shè)計(jì)思路Scheme 1 Design strategy of target compounds
目標(biāo)化合物的設(shè)計(jì)思路見圖式1,合成路線見圖式2。
Bruker Advance Ш 400/500MHz 核磁共振儀,德國(guó)Bruker 公司;Bruker TENSOR27 紅外光譜儀,德國(guó)Bruker 公司;ZF-6 型三用紫外線分析儀,上海嘉鵬科技有限公司;RE-52 旋轉(zhuǎn)蒸發(fā)器,上海嘉鵬科技有限公司;ALC-210.4 電子分析天平,上海精科天平儀器公司;DHG-9240A 型電熱恒溫鼓風(fēng)干燥箱,上海精宏實(shí)驗(yàn)設(shè)備有限公司;國(guó)華88-1 大功率磁力攪拌器,常州國(guó)華電器有限公司;ZSA302 體視顯微鏡,重慶光電儀器有限公司;XT-415 型雙目顯微熔點(diǎn)測(cè)定儀,北京泰克儀器有限公司;Bruker SMART APEX II 晶體衍射儀,德國(guó)Bruker 公司。
200~300 目柱層析硅膠 (粒徑54~74 μm) 和GF254薄層層析硅膠,青島海洋化工廠;核磁共振光譜測(cè)試所用溶劑為氘代氯仿 (CDCl3),以四甲基硅烷 (TMS) 為內(nèi)標(biāo)物;所用試劑和溶劑均為分析純。
對(duì)照藥劑:98.32%螺螨酯 (spirodiclofen) 原藥,購(gòu)于陜西美邦農(nóng)藥有限公司。
1.2.1 中間體4 的合成 參考文獻(xiàn)方法[16]進(jìn)行。取DMF (5 mmol) 于100 mL 圓底燒瓶中并置于0 ℃冰浴中攪拌,逐滴加入三氯氧磷 (5 mmol) 后繼續(xù)攪拌30 min。將胡椒堿 (1 mmol) 溶于DMF(5 mL) 中,緩慢逐滴加到上述反應(yīng)液中。滴加完畢后,將反應(yīng)瓶置于油浴中繼續(xù)攪拌,并逐漸升溫至90 ℃。待薄層層析(TLC)監(jiān)測(cè) (V(石油醚,PE)/V(乙酸乙酯,EA) = 2 : 1) 反應(yīng)完成后,將反應(yīng)瓶重新置于冰浴中,用20%氫氧化鈉水溶液調(diào)節(jié)pH 值至8~9,繼續(xù)攪拌30 min。過(guò)濾,濾餅放置烘箱中干燥,然后用硅膠柱層析 (V(PE)/V(EA) =2 : 1) 分離提純,得到化合物4。黃色固體,產(chǎn)率55%,熔點(diǎn) (m.p.) 184~186 ℃; IR (KBr),ν/cm-1:3052, 2937, 2858, 2733, 1678, 1607, 1445, 1256,1188, 812, 707;1H NMR (500 MHz, CDCl3)δ: 9.49(s, 1H), 7.12 (d,J= 11.5 Hz, 1H), 6.97~7.03 (m, 3H),6.80~6.89 (m, 2H), 6.01 (s, 2H), 3.72~3.75 (m, 2H),3.24~3.26 (m, 2H), 1.64~1.69 (m, 4H), 1.50~1.57 (m,2H);13C NMR (125 MHz, CDCl3)δ: 189.74, 163.92,149.64, 149.47, 148.50, 144.61, 137.51, 129.96,124.45, 121.57, 108.71, 106.41, 101.69, 48.01, 42.59,26.66, 25.83, 24.52.HRMS [ESI]: C18H19NNaO4([M + Na]+), 理論值:336.1212;測(cè)定值:336.1194.
1.2.2 中間體5 的合成 參考文獻(xiàn)方法[17]進(jìn)行。將中間體4 (2 mmol) 溶于甲醇 (5 mL) 中,冰浴條件下攪拌,溫度降至0 ℃后,緩慢加入NaBH4(3 mmol) 繼續(xù)攪拌,TLC (V(二氯甲烷,DCM)/V(EA) =4 : 1) 跟蹤監(jiān)測(cè)至反應(yīng)完成;加入清水 (15 mL) 淬滅反應(yīng),乙酸乙酯 (30 mL × 3) 萃取,合并有機(jī)相,干燥,減壓濃縮,硅膠柱層析 (V(DCM)/V(EA) =4 : 1) 分離,得到中間體5。淡黃色固體,產(chǎn)率89%, m.p.118~120 ℃; IR (KBr),ν/cm-1: 3393,2937, 2856, 1608, 1476, 1440, 1247, 1102, 1030, 806;1H NMR (500 MHz, CDCl3)δ: 6.88 (d,J= 1.0 Hz,1H), 6.78 (dd,J= 1.5, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H), 6.30~6.37 (m, 1H), 5.96(s, 2H), 4.30 (s, 2H), 3.68~3.70 (m, 2H), 3.43~3.45(m, 2H), 1.63~1.66 (m, 4H), 1.50~1.53 (m, 2H);13C NMR (100 MHz, CDCl3)δ: 168.81, 148.14, 147.74,136.30, 135.20, 131.23, 127.98, 122.29, 121.92,108.46, 105.55, 101.23, 64.43, 47.92, 42.45, 26.73,25.86, 24.50; HRMS [ESI]: C18H21NNaO4([M +Na]+), 理論值:338.1368;測(cè)定值:338.1353.
1.2.3 中間體6 的合成 參考文獻(xiàn)方法[18]進(jìn)行。將1,4-二溴丁烷 (3 mmol) 和NaH (3 mmol) 溶于DMF (5 mL) 中,冰浴條件下攪拌。再將中間體5(1.5 mmol) 分批緩慢加入到反應(yīng)中,繼續(xù)攪拌至TLC (V(PE)/V(EA) = 1 : 1) 監(jiān)測(cè)反應(yīng)完全。然后加入乙酸乙酯 (40 mL) 稀釋反應(yīng)體系,用0.1 mol/L稀鹽酸 (20 mL × 3) 洗滌,有機(jī)相用無(wú)水硫酸鈉干燥,減壓濃縮,硅膠柱層析 (V(PE)/V(EA) = 1:1)分離,得到中間體6,淡黃色固體,產(chǎn)率74%,m.p.64~66 ℃; IR (KBr),ν/cm-1: 3016, 2933, 2856,1622, 1487, 1442, 1251, 1090, 1027, 609;1H NMR(500 MHz, CDCl3)δ: 6.89 (s, 1H), 6.81 (dd,J= 1.5, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H),6.50~6.57 (m, 2H), 6.24~6.31 (m, 1H), 5.96 (s, 2H),4.17 (s, 2H), 3.69~3.71 (m, 2H), 3.49 (t, J = 6.0 Hz,2H), 3.42~3.45 (m, 4H), 1.91~1.98 (m, 2H),1.70~1.75 (m, 2H), 1.63~1.66 (m, 4H), 1.50~1.52 (m,2H);13C NMR (125 MHz, CDCl3)δ: 168.21, 148.17,147.80, 135.27, 134.20, 131.23, 128.83, 122.39,121.95, 108.48, 105.55, 101.26, 72.90, 70.01, 47.83,42.40, 33.80, 29.73, 28.32, 26.64, 25.92, 24.58;HRMS [ESI]: C22H28BrNNaO4([M + Na]+), 理論值:472.1099;測(cè)定值:472.1100.
1.2.4 目標(biāo)化合物8a~8z 的合成 參考文獻(xiàn)方法[19]進(jìn)行,將中間體6 (0.2 mmol),Cs2CO3(0.3 mmol) 和化合物7a~7z (0.3 mmol) (制備按照參考文獻(xiàn)[15]) 溶于乙腈 (5 mL) 中,置于40 ℃油浴中攪拌。TLC (V(PE)/V(EA) = 1 : 1 或V(DCM)/V(丙酮,AT) = 6 : 1) 跟蹤監(jiān)測(cè),反應(yīng)完全后,加入清水 (15 mL),乙酸乙酯 (30 mL × 3) 萃取,合并有機(jī)相,并用無(wú)水硫酸鈉干燥,減壓濃縮,制備薄層層析 (V(PE)/V(EA) = 1 : 1 或V(DCM)/V(AT) =6:1) 分離,得到目標(biāo)化合物8a~8z,產(chǎn)率38%~77%。
(2Z,4E)-2-((5-苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8a):產(chǎn)率59%,淡黃色液體; IR (KBr),ν/cm-1:3417, 2934, 2858, 1713, 1623, 1477, 1444, 1247, 1105, 1034,699;1H NMR (500 MHz, CDCl3)δ: 7.99 (dd,J= 2.0, 8.5 Hz,2H), 7.46~7.53 (m, 3H), 6.89 (d,J= 1.0 Hz, 1H), 6.80 (dd,J=1.5, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H),6.25~6.32 (m, 1H), 5.95 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m,2H), 3.52 (t,J= 6.5 Hz, 2H), 3.42 (t,J= 5.5 Hz, 2H), 3.32 (t,J= 7.5 Hz, 2H), 1.92~1.97 (m, 2H), 1.74~1.79 (m, 2H),1.62~1.65 (m, 4H), 1.48~1.51 (m, 2H); HRMS [ESI]:C30H34N3O5S ([M + H]+), 理論值:548.2219;測(cè)定值:548.2209.
(2Z,4E)-2-((5-(2-氟)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8b):產(chǎn)率64%,黃色液體; IR (KBr),ν/cm-1: 3417, 2933, 2857, 1741, 1623, 1477, 1357, 1246, 1036,768;1H NMR (500 MHz, CDCl3)δ: 7.98 (t,J= 8.0 Hz, 1H),7.49~7.53 (m, 1H), 7.27~7.29 (m, 1H), 7.21~7.25 (m, 1H),6.89 (s, 1H), 6.80 (dd,J= 1.5, 8.0 Hz, 1H), 6.73 (d,J= 8.0 Hz,1H), 6.49~6.57 (m, 2H), 6.25~6.32 (m, 1H), 5.95 (s, 2H), 4.19(s, 2H), 3.69-3.71 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.43 (t,J=5.0 Hz, 2H), 3.32 (t,J= 7.5 Hz, 2H), 1.92~1.98 (m, 2H),1.74~1.79 (m, 2H), 1.63~1.65 (m, 4H), 1.49~1.52 (m, 2H);HRMS [ESI]: C30H32FN3NaO5S ([M + Na]+), 理論值:588.1944;測(cè)定值:588.1929.
(2Z,4E)-2-((5-(3-氟)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8c):產(chǎn)率58%,黃色液體; IR (KBr),ν/cm-1: 3449, 2934, 2858, 1739, 1624, 1475, 1456, 1220, 1106,1037, 867, 796;1H NMR (500 MHz, CDCl3)δ: 7.80 (d,J= 7.5 Hz, 1H), 7.68 (d,J= 9.0 Hz, 1H), 7.44~7.49 (m, 1H),7.19~7.23 (m, 1H), 6.89 (s, 1H), 6.80 (dd,J= 1.0, 8.0 Hz, 1H),6.73 (d,J= 8.0 Hz, 1H), 6.49~6.57 (m, 2H), 6.25~6.32 (m,1H), 5.95 (s, 2H), 4.19 (s, 2H), 3.69~3.71 (m, 2H), 3.52 (t,J=6.0 Hz, 2H), 3.43 (t,J= 5.0 Hz, 2H), 3.33 (t,J= 7.5 Hz, 2H),1.92~1.98 (m, 2H), 1.74~1.80 (m, 2H), 1.62~1.65 (m, 4H),1.49~1.52 (m, 2H); HRMS [ESI]: C30H32FN3NaO5S ([M +Na]+), 理論值:588.1944;測(cè)定值:588.1923.
(2Z,4E)-2-((5-(4-氟)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8d):產(chǎn)率50%, 黃色固體, m.p.77~79 ℃;IR (KBr),ν/cm-1: 3418, 2930, 2858, 1736, 1626, 1438, 1220,1109, 1042, 801;1H NMR (500 MHz, CDCl3)δ: 7.98~8.01 (m,2H), 7.16 (t,J= 8.5 Hz, 2H), 6.88 (s, 1H), 6.80 (d,J= 7.0 Hz,1H), 6.73 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H), 6.25~6.32(m, 1H), 5.95 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.0 Hz, 2H), 3.32 (t,J= 7.5 Hz,2H), 1.91~1.97 (m, 2H), 1.74~1.79 (m, 2H), 1.62~1.65 (m,4H), 1.49~1.52 (m, 2H); HRMS [ESI]: C30H33FN3O5S ([M +H]+), 理論值:566.2125;測(cè)定值:566.2114.
(2Z,4E)-2-((5-(2-氯)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8e):產(chǎn)率59%,黃色液體; IR (KBr),ν/cm-1: 3442, 2933, 2857, 1739, 1624, 1446, 1361, 1245, 1096,1035, 769, 728;1H NMR (400 MHz, CDCl3)δ: 7.93 (dd,J=2.0, 8.0 Hz, 1H), 7.52 (dd,J= 0.8, 7.6 Hz, 1H), 7.43~7.47 (m,1H), 7.37~7.41 (m, 1H), 6.89 (d,J= 1.6 Hz, 1H), 6.80 (dd,J=1.2, 8.0 Hz, 1H), 6.74 (d,J= 8.4 Hz, 1H), 6.49~6.58 (m, 2H),6.24~6.33 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m,2H), 3.51 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.6 Hz, 2H), 3.32 (t,J= 7.2 Hz, 2H), 1.92~1.99 (m, 2H), 1.73~1.80 (m, 2H),1.62~1.65 (m, 4H), 1.48~1.52 (m, 2H);13C NMR (100 MHz,CDCl3)δ: 168.21, 165.16, 164.00, 148.14, 147.76, 135.26,134.15, 132.96, 132.32, 131.24, 130.93, 128.88, 127.09,122.97, 122.39, 121.93, 108.45, 105.55, 101.22, 72.88, 70.20,47.83, 42.40, 32.47, 28.63, 26.63, 26.37, 25.91, 24.55; HRMS[ESI]: C30H33ClN3O5S ([M + H]+), 理論值: 582.1829;測(cè)定值:582.1805.
(2Z,4E)-2-((5-(3-氯)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8f):產(chǎn)率56%,淡黃色液體; IR (KBr),ν/cm-1: 3448, 2933, 2857, 1723, 1624, 1450, 1359, 1246, 1107,1034, 784;1H NMR (400 MHz, CDCl3)δ: 7.98 (s, 1H), 7.88(d,J= 7.6 Hz, 1H), 7.41~7.50 (m, 2H), 6.89 (s, 1H), 6.80 (d,J= 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.48~6.57 (m, 2H),6.24~6.33 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m,2H), 3.51 (t,J= 6.4 Hz, 2H), 3.42 (t,J= 5.2 Hz, 2H), 3.33 (t,J= 7.2 Hz, 2H), 1.92~1.98 (m, 2H), 1.74~1.80 (m, 2H),1.61~1.66 (m, 4H), 1.48~1.52 (m, 2H);13C NMR (100 MHz,CDCl3)δ: 168.18, 165.03, 164.51, 148.14, 147.76, 135.27,135.17, 134.14, 131.63, 131.23, 130.43, 128.86, 126.58,125.28, 124.70, 122.37, 121.93, 108.45, 105.54, 101.23, 72.87,70.16, 47.82, 42.38, 32.46, 28.60, 26.64, 26.24, 25.91, 24.55;HRMS [ESI]: C30H32ClN3NaO5S ([M + Na]+), 理論值:604.1649;測(cè)定值:604.1605.
(2Z,4E)-2-((5-(4-氯)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8g):產(chǎn)率67%, 淡黃色固體, m.p.101~103 ℃; IR (KBr),ν/cm-1: 3418, 2929, 2858, 1715, 1620, 1438,1365, 1225, 1101, 1050, 805;1H NMR (400 MHz, CDCl3)δ:7.92 (d,J= 8.8 Hz, 2H), 7.45 (d,J= 8.8 Hz, 2H), 6.88 (d,J=1.2 Hz, 1H), 6.80 (dd,J= 1.6, 8.4 Hz, 1H), 6.74 (d,J= 8.0 Hz,1H), 6.48~6.57 (m, 2H), 6.24~6.33 (m, 1H), 5.96 (s, 2H), 4.18(s, 2H), 3.68~3.70 (m, 2H), 3.51 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.6 Hz, 2H), 3.32 (t,J= 7.2 Hz, 2H), 1.91~1.98 (m, 2H),1.73~1.80 (m, 2H), 1.62~1.66 (m, 4H), 1.48~1.52 (m, 2H);13C NMR (100 MHz, CDCl3)δ: 168.19, 164.87, 164.76, 148.14,147.77, 137.84, 135.27, 134.14, 131.23, 129.44, 128.86,127.90, 122.37, 122.15, 121.92, 108.46, 105.55, 101.23, 72.87,70.17, 47.82, 42.39, 32.47, 28.60, 26.64, 26.24, 25.91, 24.55;HRMS [ESI]: C30H32ClN3NaO5S ([M + Na]+), 理論值:604.1649;測(cè)定值:604.1608.
(2Z,4E)-2-((5-(2-溴)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8h):產(chǎn)率58%,黃色液體; IR (KBr),ν/cm-1: 3450, 2932, 2856, 1711, 1622, 1445, 1354, 1248, 1031,767, 530;1H NMR (500 MHz, CDCl3)δ: 7.87 (dd,J= 1.6, 7.6 Hz, 1H), 7.72 (dd,J= 0.8, 8.0 Hz, 1H), 7.42~7.46 (m, 1H),7.34~7.39 (m, 1H), 6.89 (d,J= 1.2, 1H), 6.80 (dd,J= 1.6, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.58 (m, 2H),6.24~6.33 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m,2H), 3.51 (t,J= 6.4 Hz, 2H), 3.42 (t,J= 5.2 Hz, 2H), 3.32 (t,J= 7.2 Hz, 2H), 1.92~1.99 (m, 2H), 1.73-1.80 (m, 2H),1.62~1.66 (m, 4H), 1.48~1.52 (m, 2H);13C NMR (100 MHz,CDCl3)δ: 168.19, 165.20, 164.51, 148.14, 147.76, 135.25,134.56, 134.17, 132.43, 131.39, 131.25, 128.86, 127.61,125.06, 122.40, 121.94, 121.46, 108.46, 105.55, 101.22, 72.88,70.20, 47.82, 42.39, 32.49, 28.64, 26.64, 26.39, 25.92, 24.56;HRMS [ESI]: C30H32BrN3NaO5S ([M + Na]+), 理論值:648.1144;測(cè)定值:648.1110.
(2Z,4E)-2-((5-(3-溴)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8i):產(chǎn)率50%,黃色液體; IR (KBr),ν/cm-1: 3442, 2931, 2856, 1715, 1624, 1451, 1245, 1105, 1034,795, 529;1H NMR (400 MHz, CDCl3)δ: 8.14 (t,J= 2.0 Hz,1H), 7.93 (d,J= 8.0 Hz, 1H), 7.63 (d,J= 8.0 Hz, 1H), 7.34 (t,J= 8.0 Hz, 1H), 6.89 (d,J= 2.0 Hz, 1H), 6.80 (dd,J= 1.2, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.48~6.58 (m, 2H),6.24~6.33 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m,2H), 3.51 (t,J= 6.0 Hz, 2H), 3.43 (t,J= 5.2 Hz, 2H), 3.33 (t,J= 7.2 Hz, 2H), 1.91~1.98 (m, 2H), 1.73~1.80 (m, 2H),1.62~1.65 (m, 4H), 1.48-1.52 (m, 2H);13C NMR (100 MHz,CDCl3)δ: 168.17, 165.04, 164.36, 148.13, 147.76, 135.25,134.54, 134.15, 131.23, 130.63, 129.44, 128.84, 125.49,125.14, 123.07, 122.38, 121.92, 108.45, 105.54, 101.22, 72.87,70.16, 47.81, 42.37, 32.46, 28.60, 26.63, 26.23, 25.90, 24.55;HRMS [ESI]: C30H32BrN3NaO5S ([M + Na]+), 理論值:648.1144;測(cè)定值:648.1124.
(2Z,4E)-2-((5-(4-溴)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8j):產(chǎn)率53%,黃色固體, m.p.88~90 ℃;IR (KBr),ν/cm-1: 3450, 2928, 2857, 1736, 1437, 1224, 1107,1055, 799, 530;1H NMR (400 MHz, CDCl3)δ: 7.85 (d,J= 8.4 Hz, 2H), 7.62 (d,J= 8.4 Hz, 2H), 6.88 (s, 1H), 6.80 (d,J= 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.48~6.57 (m, 2H),6.24~6.32 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68-3.70 (m,2H), 3.51 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.5 Hz, 2H), 3.32 (t,J= 7.2 Hz, 2H), 1.91~1.98 (m, 2H), 1.73~1.80 (m, 2H),1.61~1.66 (m, 4H), 1.48~1.52 (m, 2H);13C NMR (100 MHz,CDCl3)δ: 168.17, 164.96, 164.80, 148.14, 147.77, 135.25,134.16, 132.40, 131.23, 128.84, 128.03, 126.25, 122.58,122.38, 121.92, 108.46, 105.55, 101.23, 72.87, 70.16, 47.81,42.37, 32.47, 28.60, 26.64, 26.24, 25.91, 24.55; HRMS [ESI]:C30H32BrN3NaO5S ([M + Na]+), 理論值:648.1144;測(cè)定值:648.1136.
(2Z,4E)-2-((5-(2-三氟甲基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8k):產(chǎn)率40%,黃色液體; IR(KBr),ν/cm-1: 3454, 2935, 1734, 1625, 1476, 1450, 1250,1131, 1035, 724;1H NMR (500 MHz, CDCl3)δ: 8.19 (d,J=6.5 Hz, 1H), 7.84 (d,J= 7.0 Hz, 1H), 7.65~7.71 (m, 2H), 6.89(s, 1H), 6.80 (dd,J= 1.5, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H),6.50~6.57 (m, 2H), 6.25~6.32 (m, 1H), 5.95 (s, 2H), 4.18 (s,2H), 3.68~3.71 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.43 (t,J=5.0 Hz, 2H), 3.30 (t,J= 7.5 Hz, 2H), 1.91~1.97 (m, 2H),1.74~1.79 (m, 2H), 1.62~1.65 (m, 4H), 1.48~1.52 (m, 2H);HRMS [ESI]: C31H32F3N3NaO5S ([M + Na]+), 理論值:638.1912;測(cè)定值:638.1865.
(2Z,4E)-2-((5-(3-三氟甲基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8l):產(chǎn)率51%,黃色液體; IR(KBr),ν/cm-1: 3455, 2935, 2858, 1738, 1625, 1476, 1445,1352, 1247, 1034, 806, 695;1H NMR (500 MHz, CDCl3)δ:8.25 (s, 1H), 8.19 (d,J= 8.0 Hz, 1H), 7.76 (d,J= 7.5 Hz, 1H),7.72 (t,J= 8.0 Hz, 1H), 6.88 (s, 1H), 6.80 (dd,J= 1.0, 8.0 Hz,1H), 6.73 (d,J= 8.0 Hz, 1H), 6.49~6.57 (m, 2H), 6.25~6.32(m, 1H), 5.95 (s, 2H), 4.19 (s, 2H), 3.68~3.70 (m, 2H), 3.52 (t,J= 6.5 Hz, 2H), 3.43 (t,J= 5.0 Hz, 2H), 3.35 (t,J= 7.0 Hz,2H), 1.93~1.99 (m, 2H), 1.75~1.80 (m, 2H), 1.62~1.66 (m,4H), 1.49~1.53 (m, 2H); HRMS [ESI]: C31H32F3N3NaO5S([M + Na]+), 理論值:638.1912;測(cè)定值:638.1886.
(2Z,4E)-2-((5-(4-三氟甲基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8m):產(chǎn)率51%,黃色固體, m.p.67~69 ℃; IR (KBr),ν/cm-1: 3447, 2937, 2859, 1737, 1629,1444, 1221, 1115, 1025, 793;1H NMR (500 MHz, CDCl3)δ:8.11 (d,J= 8.0 Hz, 2H), 7.74 (d,J= 8.5 Hz, 2H), 6.88 (s, 1H),6.80 (dd,J= 1.0, 8.0 Hz, 1H), 6.73 (d,J= 8.0 Hz, 1H), 6.49-6.56 (m, 2H), 6.25~6.32 (m, 1H), 5.95 (s, 2H), 4.18 (s, 2H),3.68~3.70 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.0 Hz,2H), 3.35 (t,J= 7.0 Hz, 2H), 1.93~1.99 (m, 2H), 1.75~1.80(m, 2H), 1.62~1.65 (m, 4H), 1.49~1.52 (m, 2H); HRMS [ESI]:C31H32F3N3NaO5S ([M + Na]+), 理論值: 638.1912;測(cè)定值:638.1888.
(2Z,4E)-2-((5-(2-硝基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8n):產(chǎn)率56%,淡黃色液體; IR (KBr),ν/cm-1: 3425, 2933, 2857, 1714, 1621, 1476, 1449, 1249, 1104,1037, 854, 724;1H NMR (500 MHz, CDCl3)δ: 8.00 (d,J= 7.5 Hz, 1H), 7.94 (dd,J= 1.0, 7.5 Hz, 1H), 7.71~7.77 (m, 2H),6.89 (s, 1H), 6.81 (d,J= 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H),6.50~6.57 (m, 2H), 6.25~6.33 (m, 1H), 5.96 (s, 2H), 4.18 (s,2H), 3.68~3.70 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.43-3.45 (m,2H), 3.29 (t,J= 7.0 Hz, 2H), 1.90-1.96 (m, 2H), 1.73~1.79 (m,2H), 1.62~1.66 (m, 4H), 1.48-1.53 (m, 2H); HRMS [ESI]:C30H32N4NaO7S ([M + Na]+), 理論值:615.1889;測(cè)定值:615.1865.
(2Z,4E)-2-((5-(3-硝基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8o):產(chǎn)率65%,淡黃色液體; IR (KBr),ν/cm-1: 3454, 2933, 2858, 1738, 1623, 1445, 1225, 1106, 1040,856, 802, 701;1H NMR (500 MHz, CDCl3)δ: 8.81 (s, 1H),8.34~8.37 (m, 2H), 7.69 (t,J= 8.0 Hz, 1H), 6.87 (s, 1H), 6.79(dd,J= 1.5, 8.0 Hz, 1H), 6.73 (d,J= 8.0 Hz, 1H), 6.49~6.56(m, 2H), 6.25~6.32 (m, 1H), 5.95 (s, 2H), 4.19 (s, 2H),3.68~3.70 (m, 2H), 3.53 (t,J= 6.0 Hz, 2H), 3.43 (t,J= 5.5 Hz,2H), 3.36 (t,J= 7.5 Hz, 2H), 1.94~2.00 (m, 2H), 1.75~1.81(m, 2H), 1.62~1.67 (m, 4H), 1.50-1.52 (m, 2H); HRMS [ESI]:C30H32N4NaO7S ([M + Na]+), 理論值:615.1889;測(cè)定值:615.1868.
(2Z,4E)-2-((5-(4-硝基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8p):產(chǎn)率58%, 淡黃色固體, m.p.79~81 ℃; IR (KBr),ν/cm-1: 3418, 2931, 1623, 1450, 1247, 1110,853, 798;1H NMR (500 MHz, CDCl3)δ: 8.34 (d,J= 9.0 Hz,2H), 8.18 (d,J= 9.0 Hz, 2H), 6.87 (s, 1H), 6.80 (dd,J= 1.0,8.0 Hz, 1H), 6.73 (dd,J= 1.5, 8.0 Hz, 1H), 6.49~6.56 (m, 2H),6.25~6.32 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68-3.70 (m,2H), 3.53 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.0 Hz, 2H), 3.36 (t,J= 7.5 Hz, 2H), 1.94~2.00 (m, 2H), 1.75~1.80 (m, 2H),1.63~1.66 (m, 4H), 1.48~1.52 (m, 2H); HRMS [ESI]:C30H32N4NaO7S ([M + Na]+), 理論值:615.1889;測(cè)定值:615.1881.
(2Z,4E)-2-((5-(2-甲基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8q):產(chǎn)率62%,無(wú)色液體; IR (KBr),ν/cm-1: 3452, 2931, 2857, 1725, 1624, 1478, 1248, 1106, 1037,726;1H NMR (500 MHz, CDCl3)δ: 7.86 (d,J= 8.0 Hz, 1H),7.38~7.41 (m, 1H), 7.29~7.33 (m, 2H), 6.89 (d,J= 1.0 Hz,1H), 6.80 (dd,J= 1.5, 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H),6.49-6.56 (m, 2H), 6.25~6.32 (m, 1H), 5.96 (s, 2H), 4.18 (s,2H), 3.68~3.70 (m, 2H), 3.52 (t,J= 6.5 Hz, 2H), 3.42 (t,J=5.5 Hz, 2H), 3.32 (t,J= 7.5 Hz, 2H), 2.68 (s, 3H), 1.93~1.99(m, 2H), 1.74~1.80 (m, 2H), 1.62~1.65 (m, 4H), 1.48~1.52 (m,2H); HRMS [ESI]: C31H35N3NaO5S ([M + Na]+), 理論值:584.2195;測(cè)定值:584.2181.
(2Z,4E)-2-((5-(3-甲基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8r):產(chǎn)率67%,無(wú)色液體; IR (KBr),
ν/cm-1: 3449, 2931, 2857, 1625, 1476, 1249, 1098, 1035, 851,798, 684;1H NMR (500 MHz, CDCl3)δ: 7.82 (s, 1H), 7.78 (d,J= 8.0 Hz, 1H), 7.37 (d,J= 8.0 Hz, 1H), 7.31 (d,J= 7.5 Hz,1H), 6.89 (d,J= 1.5 Hz, 1H), 6.80 (dd,J= 1.0, 8.0 Hz, 1H),6.74 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H), 6.25~6.32 (m,1H), 5.95 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m, 2H), 3.52 (t,J=6.0 Hz, 2H), 3.42 (t,J= 5.5 Hz, 2H), 3.32 (t,J= 7.0 Hz, 2H),2.42 (s, 3H), 1.91~1.97 (m, 2H), 1.74~1.79 (m, 2H), 1.61~1.65(m, 4H), 1.48~1.51 (m, 2H); HRMS [ESI]: C31H35N3NaO5S([M + Na]+), 理論值:584.2195;測(cè)定值:584.2163.
(2Z,4E)-2-((5-(4-甲基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8s):產(chǎn)率60%,無(wú)色液體; IR (KBr),ν/cm-1: 3450, 2932, 2857, 1622, 1476, 1249, 1107, 1034, 814;1H NMR (500 MHz, CDCl3)δ: 7.87 (d,J= 8.0 Hz, 2H), 7.27(d,J= 8.0 Hz, 2H), 6.88 (d,J= 1.5 Hz, 1H), 6.80 (dd,J= 1.5,8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H),6.24~6.31 (m, 1H), 5.95 (s, 2H), 4.18 (s, 2H), 3.68~3.70 (m,2H), 3.51 (t,J= 6.5 Hz, 2H), 3.42 (t,J= 5.5 Hz, 2H), 3.31 (t,J= 7.0 Hz, 2H), 2.41 (s, 3H), 1.91~1.97 (m, 2H), 1.73~1.76(m, 2H), 1.61~1.65 (m, 4H), 1.48~1.51 (m, 2H); HRMS [ESI]:C31H36N3O5S ([M + H]+), 理論值:562.2376;測(cè)定值:562.2359.
(2Z,4E)-2-((5-(2-甲氧基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8t):產(chǎn)率56%,淡黃色液體; IR(KBr),ν/cm-1: 3454, 2933, 2855, 1729, 1618, 1478, 1444,1254, 1115, 1031, 733;1H NMR (400 MHz, CDCl3)δ: 7.56 (d,J= 1.6, 7.6 Hz, 1H), 7.47~7.51 (m, 1H), 7.03~7.07 (m, 2H),6.89 (d,J= 1.2 Hz, 1H), 6.80 (dd,J= 1.2, 8.0 Hz, 1H), 6.74(d,J= 8.4 Hz, 1H), 6.48~6.57 (m, 2H), 6.24~6.33 (m, 1H),5.96 (s, 2H), 4.18 (s, 2H), 3.95 (s, 3H), 3.68~3.70 (m, 2H),3.51 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.2 Hz, 2H), 3.30 (t,J=7.2 Hz, 2H), 1.90~1.98 (m, 2H), 1.73~1.80 (m, 2H), 1.61~1.65(m, 4H), 1.48-1.52 (m, 2H);13C NMR (125 MHz, CDCl3)δ:168.22, 164.44, 164.07, 157.72, 148.16, 147.77, 135.24,134.22, 133.01, 131.28, 130.26, 128.84, 122.43, 121.95,120.74, 112.87, 111.92, 108.48, 105.58, 101.24, 72.89, 70.27,56.00, 47.85, 42.40, 32.44, 28.65, 26.65, 26.35, 25.94, 24.57;HRMS [ESI]: C31H35N3NaO6S ([M + Na]+), 理論值:600.2144;測(cè)定值:600.2133.
(2Z,4E)-2-((5-(3-甲氧基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8u):產(chǎn)率55%,淡黃色液體; IR(KBr),ν/cm-1: 3451, 2932, 2855, 1733, 1623, 1477, 1443,1244, 1103, 1036, 851, 795, 682;1H NMR (500 MHz, CDCl3)δ: 7.85 (dd,J= 8.0 Hz, 1H), 7.52 (s, 1H), 7.37 (t,J= 8.0 Hz,1H), 7.04 (dd,J= 1.5, 8.0 Hz, 1H), 6.89 (s, 1H), 6.80 (d,J=8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H),6.24~6.32 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.87 (s, 3H),3.68~3.70 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.5 Hz,2H), 3.32 (t,J= 7.5 Hz, 2H), 1.91~1.97 (m, 2H), 1.74~1.79(m, 2H), 1.62~1.65 (m, 4H), 1.48~1.52 (m, 2H);13C NMR(100 MHz, CDCl3)δ: 168.19, 165.64, 164.47, 159.93, 148.14,147.76, 135.24, 134.18, 131.25, 130.20, 128.84, 124.77,122.40, 121.92, 119.05, 118.13, 111.20, 108.45, 105.55,101.22, 72.88, 70.20, 55.52, 47.82, 42.38, 32.45, 28.62, 26.63,26.28, 25.91, 24.55; HRMS [ESI]: C31H35N3NaO6S ([M +Na]+), 理論值: 600.2144;測(cè)定值:600.2123.
(2Z,4E)-2-((5-(4-甲氧基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基) 胡椒堿 (8v):產(chǎn)率77%,淡黃色液體; IR(KBr),ν/cm-1: 3450, 2933, 2855, 1711, 1619, 1489, 1444,1253, 1107, 1030, 730;1H NMR (500 MHz, CDCl3)δ: 7.92 (d,J= 9.0 Hz, 2H), 6.97 (d,J= 9.0 Hz, 2H), 6.88 (s, 1H), 6.80 (d,J= 8.0 Hz, 1H), 6.73 (d,J= 8.0 Hz, 1H), 6.49~6.56 (m, 2H),6.24~6.31 (m, 1H), 5.95 (s, 2H), 4.18 (s, 2H), 3.86 (s, 3H),3.68~3.70 (m, 2H), 3.51 (t,J= 6.5 Hz, 2H), 3.42 (t,J= 5.0 Hz,2H), 3.32 (t,J= 7.0 Hz, 2H), 1.90~1.96 (m, 2H), 1.73~1.79(m, 2H), 1.62~1.65 (m, 4H), 1.49~1.52 (m, 2H);13C NMR(100 MHz, CDCl3)δ: 168.18, 165.65, 163.62, 162.22, 148.13,147.75, 135.22, 134.19, 131.24, 128.82, 128.40, 122.39,121.91, 116.20, 114.46, 108.44, 105.54, 101.22, 72.86, 70.20,55.46, 47.81, 42.37, 32.46, 28.61, 26.62, 26.30, 25.91, 24.54;HRMS [ESI]: C31H35N3NaO6S ([M + Na]+), 理論值:600.2144;測(cè)定值:600.2115.
(2Z,4E)-2-((5-(2-乙基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8w):產(chǎn)率38%,淡黃色液體; IR (KBr),ν/cm-1: 3424, 2931, 2858, 1717, 1626, 1478, 1442, 1247, 1106,1037, 711;1H NMR (400 MHz, CDCl3)δ: 7.83 (d,J= 7.6 Hz,1H), 7.42~7.46 (m, 1H), 7.35 (d,J= 7.6 Hz, 1H), 7.29 (t,J=7.2 Hz, 1H), 6.89 (d,J= 1.6 Hz, 1H), 6.80 (dd,J= 1.6, 8.0 Hz,1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49-6.57 (m, 2H), 6.24~6.33(m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68-3.71 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.42 (t,J= 5.6 Hz, 2H), 3.31 (t,J= 7.6 Hz,2H), 3.06 (q,J= 7.6 Hz, 2H), 1.92~2.00 (m, 2H), 1.73~1.80(m, 2H), 161~1.65 (m, 4H), 1.47~1.52 (m, 2H), 1.24~1.28 (m,3H);13C NMR (125 MHz, CDCl3)δ: 168.21, 165.68, 164.13,148.16, 147.78, 144.46, 135.26, 134.21, 131.41, 131.27,130.19, 129.09, 128.86, 126.16, 122.42, 122.14, 121.96,108.48, 105.57, 101.25, 72.91, 70.24, 47.85, 42.40, 32.42,28.69, 27.64, 26.66, 26.36, 25.94, 24.58, 15.30; HRMS [ESI]:C32H37N3NaO5S ([M + Na]+), 理論值:598.2352;測(cè)定值:598.2324.
(2Z,4E)-2-((5-(4-乙基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8x):產(chǎn)率49%,淡黃色液體; IR (KBr),ν/cm-1: 3421, 2932, 2859, 1725, 1623, 1477, 1445, 1247, 1107,1035, 841;1H NMR (500 MHz, CDCl3)δ: 7.90 (d,J= 8.0 Hz,2H), 7.30 (d,J= 8.0 Hz, 2H), 6.89 (s, 1H), 6.80 (d,J= 8.0 Hz,1H), 6.73 (d,J= 8.0 Hz, 1H), 6.50~6.56 (m, 2H), 6.25~6.32(m, 1H), 5.95 (s, 2H), 4.20 (s, 2H), 3.69-3.72 (m, 2H), 3.52 (t,J= 6.0 Hz, 2H), 3.43 (t,J= 5.0 Hz, 2H), 3.31 (t,J= 7.5 Hz,2H), 2.68~2.73 (m, 2H), 1.91~1.97 (m, 2H), 1.74~1.79 (m,2H), 1.62~1.65 (m, 4H), 1.49~1.52 (m, 2H), 1.24~1.27 (m,3H); HRMS [ESI]: C32H37N3NaO5S ([M + Na]+), 理論值:598.2352;測(cè)定值:598.2340.
(2Z,4E)-2-((5-(3-氰基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8y):產(chǎn)率52%,淡黃色液體; IR (KBr),ν/cm-1: 3421, 2933, 2857, 2231, 1732, 1624, 1454, 1245, 1103,1035, 805, 675;1H NMR (500 MHz, CDCl3)δ:8.27 (s, 1H),8.24 (d,J= 8.0 Hz, 1H), 7.79 (d,J= 7.5 Hz, 1H), 7.62 (t,J=8.0 Hz, 1H), 6.88 (s, 1H), 6.80~6.82 (m, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.57 (m, 2H), 6.25~6.32 (m, 1H), 5.96 (s, 2H),4.18 (s, 2H), 3.68~3.71 (m, 2H), 3.52 (t,J= 6.5 Hz, 2H), 3.43(t,J= 5.5 Hz, 2H), 3.35 (t,J= 7.0 Hz, 2H), 1.93~1.99 (m, 2H),1.75~1.80 (m, 2H), 1.63~1.66 (m, 4H), 1.49-1.52 (m, 2H);HRMS [ESI]: C31H32N4NaO5S ([M + Na]+), 理論值:595.1991;測(cè)定值:595.1980.
(2Z,4E)-2-((5-(4-氰基)苯基-1,3,4-噁二唑-2-基)-硫基-丁氧基甲基)胡椒堿 (8z):產(chǎn)率64%,淡黃色液體; IR (KBr),ν/cm-1: 3426, 2932, 2856, 2227, 1731, 1624, 1455, 1245, 1106,1033, 847, 803;1H NMR (500 MHz, CDCl3)δ: 8.10 (d,J= 8.0 Hz, 2H), 7.78 (d,J= 8.0 Hz, 2H), 6.88 (s, 1H), 6.80 (d,J= 8.0 Hz, 1H), 6.74 (d,J= 8.0 Hz, 1H), 6.49~6.58 (m, 2H),6.25~6.32 (m, 1H), 5.96 (s, 2H), 4.18 (s, 2H), 3.68-3.70 (m,2H), 3.52 (t,J= 6.5 Hz, 2H), 3.43 (t,J= 5.5 Hz, 2H), 3.35 (t,J= 7.5 Hz, 2H), 1.93~1.97 (m, 2H), 1.74~1.80 (m, 2H),1.62~1.66 (m, 4H), 1.49~1.52 (m, 2H); HRMS [ESI]:C31H32N4NaO5S ([M + Na]+), 理論值:595.1991;測(cè)定值:595.1972.
1.3.1 供試螨 朱砂葉螨T.cinnabarinus雌成螨,由西北農(nóng)林科技大學(xué)植物保護(hù)學(xué)院農(nóng)藥設(shè)計(jì)與合成實(shí)驗(yàn)室提供。
1.3.2 殺螨活性測(cè)定 參考聯(lián)合國(guó)糧食及農(nóng)業(yè)組織(FAO)推薦的玻片浸漬法[20]并加以改進(jìn):以0.1‰吐溫-80 溶液為空白對(duì)照,螺螨酯為陽(yáng)性對(duì)照,用0.1‰吐溫-80 溶液將待測(cè)樣品及對(duì)照藥物配制成質(zhì)量濃度為0.5 mg/mL 的溶液備用。將寬度為1 cm 的雙面膠粘在載玻片的一端,用0 號(hào)毛筆挑選螨齡一致、健康且活潑的朱砂葉螨雌成螨,小心整齊地將其背部粘在雙面膠上,每行粘約15~20 頭,每個(gè)玻片粘2 行。一塊玻片為一個(gè)重復(fù),每待測(cè)藥液處理重復(fù)3 次。將載玻片放入墊有浸濕海綿的托盤中保濕,托盤放入溫度為(26 ± 1) ℃、相對(duì)濕度為 (60~80)%、光照/黑暗周期為14 h/10 h 的人工氣候箱內(nèi)。4 h 后,用體視顯微鏡檢查,剔除死亡和不活潑的個(gè)體,記錄每塊載玻片上的活螨數(shù)量。然后,將載玻片 (粘有螨的一端) 浸漬在供試藥液中振蕩,5s 后取出,用濾紙條吸去多余藥液,放回托盤,再次置于人工培養(yǎng)箱中。浸藥處理后,每隔24 h 用體視顯微鏡觀察并記錄螨的死亡情況,檢查時(shí)用毛筆尖輕觸螨體,以其螯肢不動(dòng)者為死亡。按文獻(xiàn)[20]方法計(jì)算48 h 和72 h 的死亡率和校正死亡率。
根據(jù)殺螨初篩結(jié)果,選取具有較好觸殺活性的化合物,設(shè)置5~7 個(gè)濃度梯度,按照上述方法分別測(cè)定其校正死亡率。由SPSS 23.0 軟件對(duì)所得數(shù)據(jù)進(jìn)行分析,以Finney 機(jī)率值分析法求得毒力回歸方程、LC50值及95%置信區(qū)間。
1.3.3 溫室盆栽試驗(yàn) 參考文獻(xiàn)方法[21]進(jìn)行。以0.1%吐溫-80 溶液為空白對(duì)照,將陽(yáng)性對(duì)照螺螨酯、先導(dǎo)化合物胡椒堿及待測(cè)目標(biāo)化合物用0.1%吐溫-80 制成質(zhì)量濃度為0.3 mg/mL 的溶液備用。在提前準(zhǔn)備好的供試植株豇豆苗上接螨齡一致、健康、活潑的朱砂葉螨雌成螨,每株豇豆苗接50 頭螨,每盆3 株為一個(gè)重復(fù),每個(gè)待測(cè)化合物3 個(gè)重復(fù)。4 h 后,將10 mL 供試藥液均勻噴至3 盆植株葉片上。每天觀察植株危害情況,記錄植株上活螨數(shù),按文獻(xiàn)[21]方法計(jì)算施藥后第1、3、5 天螨口減退率及防治效果。
本文以胡椒堿為先導(dǎo)化合物,通過(guò)維爾斯麥爾哈克 (Vilsmeier-Haack) 反應(yīng)得到中間體4,其在硼氫化鈉條件下還原得到中間體5;然后與1,4-二溴丁烷反應(yīng)得中間體6;最后,中間體6 與一系列不同取代的2-巰基-5-苯基-1,3,4-噁二唑 (7a~7z) 反應(yīng)得到26 個(gè)目標(biāo)化合物8a~8z。通過(guò)文獻(xiàn)檢索,所合成的化合物均未見報(bào)道,其結(jié)構(gòu)通過(guò)核磁共振氫譜 (或碳譜)、紅外光譜和高分辨質(zhì)譜進(jìn)行表征。如圖1 所示,通過(guò)化合物8g (CCDC: 2168547)的X-射線單晶衍射確定了其空間構(gòu)型,發(fā)現(xiàn)其C2 位雙鍵的構(gòu)型為順式,即通過(guò)在胡椒堿羰基的鄰位區(qū)域選擇性地引入醛基后,使其C2 位雙鍵的構(gòu)型發(fā)生了變化。
圖1 化合物8g 的X-射線衍射單晶結(jié)構(gòu)Fig.1 X-ray crystal structure of compound 8g
通過(guò)玻片浸漬法測(cè)定化合物1、4~6、8a~8z及陽(yáng)性對(duì)照螺螨酯在0.5 mg/mL 質(zhì)量濃度下對(duì)朱砂葉螨雌成螨的48 和72 h 殺螨活性。結(jié)果如表1 所示,胡椒堿 (1) 及中間體4~6 在72 h 時(shí)的校正死亡率 (corrected mortality rates,CMRs) 分別為21.2%、28.4%、12.0%和23.8%。說(shuō)明在胡椒堿C2 位引入羥基,不利于殺螨活性;羥基成醚后,其殺螨活性得到提高。繼續(xù)引入1,3,4-噁二唑活性基團(tuán),部分目標(biāo)化合物的殺螨活性得到顯著提高,并且其活性與取代基R 的位置和電子效應(yīng)相關(guān)。當(dāng)苯環(huán)上無(wú)取代基時(shí),化合物8a (R = H) 72 h的CMR 為34.8%;當(dāng)苯環(huán)上引入氟原子時(shí),其對(duì)位取代化合物的殺螨活性得到顯著提高,如化合物8d (72 h CMR:41.3%),而鄰位或間位取代化合物的活性均降低,如化合物8b 與8c 的72 h CMRs分別為30.5% 與18.0%;當(dāng)苯環(huán)上引入氯原子、溴原子、乙基或腈基時(shí),其殺螨活性均降低,且在引入溴原子或乙基時(shí)活性顯著降低,如化合物8h (R = 2-Br;72 h CMR:8.5%) 和化合物8w (R =2-CH2CH3;72 h CMR:8.9%);當(dāng)苯環(huán)上引入甲基或甲氧基時(shí),除化合物8t (R = 2-OCH3;72 h CMR:24.3%) 外,其殺螨活性均得到提高,尤其是間位取代化合物,如化合物8r (R = 3-CH3;72 h CMR:64.4%) 和化合物8u (R = 3-OCH3;72 h CMR:67.4%),其殺螨活性均大于60%。此外,取代基R 還具有明顯的位置效應(yīng)。例如,當(dāng)R 為鹵素原子或三氟甲基時(shí),對(duì)位取代化合物的殺螨活性明顯高于鄰位和間位取代化合物的;然而,當(dāng)R 為硝基時(shí)則正好相反,即對(duì)位取代化合物的殺螨活性顯著低于鄰位和間位取代化合物,如化合物8p(R = 4-NO2;72 h CMR:12.0%)的殺螨活性顯著低于化合物8n (R = 2-NO2;72 h CMR:40.9%) 和8o (R = 3-NO2;72 h CMR:41.1%)。
表1 化合物1、4~6、8a~8z 和螺螨酯在0.5 mg/mL質(zhì)量濃度下對(duì)朱砂葉螨雌成螨的殺螨活性Table 1 Acaricidal activities of 1, 4-6, 8a-8z, and spirodiclofen against female adults of T.cinnabarinus at 0.5 mg/mL
如表2 所示,化合物1、8m、8r、8u 和螺螨酯對(duì)朱砂葉螨72 h LC50值分別為15.64、0.41、0.36、0.32 和0.12 mg/mL,即所測(cè)化合物的殺螨活性是胡椒堿的38.1~48.9 倍。另外,由圖2 可以看出,噴霧法測(cè)定的化合物1、8r、8u 和螺螨酯在0.3 mg/mL 下對(duì)朱砂葉螨第5 天的盆栽防治效果分別為20.0%、56.2%、61.8%和76.5%?;衔?、8r 和8u 處理豇豆苗后5 d,空白對(duì)照組和胡椒堿處理組葉片均有大量被朱砂葉螨侵害的黃色斑點(diǎn),而8r 和8u 處理組葉片黃斑不明顯,表現(xiàn)出較好的防治效果 (圖3)。今后我們將對(duì)化合物8m、8r 及8u 進(jìn)行進(jìn)一步結(jié)構(gòu)優(yōu)化,通過(guò)改變連接臂的長(zhǎng)短、硫醚氧化為亞砜和砜等,來(lái)發(fā)現(xiàn)殺螨活性更好的化合物。
表2 化合物1、8m、8r、8u 和螺螨酯對(duì)朱砂葉螨72 h 的LC50 值Table 2 LC50 values of 1, 8m, 8r, 8u and spirodiclofen at 72 h against T.cinnabarinus
圖2 化合物1、8r、8u 和螺螨酯在0.3 mg/mL 下對(duì)朱砂葉螨的室內(nèi)防治效果Fig.2 Control efficacies of 1, 8r, 8u and spirodiclofen against T.cinnabarinus in the greenhouse tests at 0.3 mg/mL
圖3 噴施化合物1、8r 和8u 后第5 天豇豆苗 (被朱砂葉螨雌成螨侵染) 照片 (CK 為空白對(duì)照)Fig.3 The pictures of asparagus bean seedlings (infested with the female adults of T.cinnabarinus) after spraying with 1, 8r and 8u on the 5th day(CK: the blank control group)
本文以胡椒堿為先導(dǎo)化合物,設(shè)計(jì)并合成了一系列結(jié)構(gòu)新穎的含1,3,4-噁二唑雜環(huán)的胡椒堿類衍生物8a~8z。部分化合物在0.5 mg/mL 質(zhì)量濃度下對(duì)朱砂葉螨具有較好的殺螨活性,尤其是化合物8m、8r 及8u 表現(xiàn)出良好的殺螨活性,其活性是胡椒堿的38.1~48.9 倍?;衔?r 及8u 在0.3 mg/mL 質(zhì)量濃度下對(duì)朱砂葉螨具有較好的室內(nèi)防效。構(gòu)效關(guān)系結(jié)果表明,在胡椒堿C2 位引入1,3,4-噁二唑雜環(huán)有利于提高其殺螨活性,且殺螨活性與噁二唑苯環(huán)上的取代基密切相關(guān)?;衔?m、8r 及8u 可作為先導(dǎo)化合物進(jìn)一步進(jìn)行結(jié)構(gòu)優(yōu)化來(lái)研究其殺螨活性,本研究結(jié)果為胡椒堿類新農(nóng)藥的研發(fā)提供了一定的理論依據(jù)。