技術(shù)背景
戊酸苯酯,英文名稱為phenyl pentanoate,其CAS號為20115-23-5,密度為1.009 g/cm3,沸點(diǎn)為249.5oC(760 mmHg)。戊酸苯酯為戊酸的酯形式,可用作醫(yī)藥合成中間體,具有較為廣泛的應(yīng)用。

戊酸苯酯的合成
戊酸苯酯的合成方法報(bào)道較多,方法也較多。Fengqian Zhao, Patrizio Russo, Raffaella Mancuso, Bartolo Gabriele以及Xiao-Feng Wu在其研究論文《Copper-catalyzed carbonylative coupling of alkyl iodides with phenols for the synthesis of esters》中對戊酸苯酯的合成方法進(jìn)行了報(bào)道[1]。其合成戊酸苯酯的方法如下:向4mL螺旋蓋小瓶中裝入溴化亞銅二甲硫醚(4.1mg,10mol%)、bpy(3.2mg,10mmol%)、苯酚(18.8mg,0.2mmol)、Cs2CO3(130mg,0.4mmol,2.0當(dāng)量)和烘干的攪拌棒。小瓶由特氟綸隔膜和酚醛帽封閉,并用針與大氣相連。用氬氣和真空沖洗小瓶三次后,用注射器注射干燥的甲苯(2.0mL)和1-碘丁烷(34.1μL,0.3 mmol)。將小瓶固定在合金板上,放入Parr 4560系列高壓釜(300mL)中。在室溫下,用一氧化碳沖洗高壓釜三次,并加入40bar的一氧化碳。高壓釜在50°C下反應(yīng)15小時(shí)。之后,將高壓釜冷卻至室溫,小心釋放壓力。通過硅膠色譜法(戊烷/EA=50:1,Rf=0.3)純化粗產(chǎn)物,得到無色油狀產(chǎn)物戊酸苯酯(33.2mg,93%)。此外,Qingqing Zhang, Shuyang Liu, Jinglan Lei, Yongqiang Zhang, Changgong Meng, Chunying Duan以及Yunhe Jin在其研究論文《Iron-Catalyzed Photoredox Functionalization of Methane and Heavier Gaseous Alkanes: Scope, Kinetics, and Computational Studies》中采用了另一種方法,對戊酸苯酯進(jìn)行了合成[2]。根據(jù)其一般程序步驟,使用丙烯酸苯酯(14.8mg,0.1mmol)、FeCl3·6H2O(0.8mg,0.1當(dāng)量)和乙腈(5mL)。12小時(shí)后,用乙醚稀釋反應(yīng)溶液,用去離子水洗滌,真空濃縮有機(jī)層。然后,使用石油醚/乙酸乙酯(10:1v/v)作為洗脫劑系統(tǒng)通過柱色譜法純化粗產(chǎn)物,得到無色油狀產(chǎn)物(5.9mg,33%)。
參考文獻(xiàn)
[1] Fengqian Zhao, Patrizio Russo, Raffaella Mancuso, Bartolo Gabriele, Xiao-Feng Wu. Copper-catalyzed carbonylative coupling of alkyl iodides with phenols for the synthesis of esters. Journal of Catalysis[J]; 2022, 413, 907–912.
[2] Qingqing Zhang, Shuyang Liu, Jinglan Lei, Yongqiang Zhang, Changgong Meng, Chunying Duan, Yunhe Jin. Iron-Catalyzed Photoredox Functionalization of Methane and Heavier Gaseous Alkanes: Scope, Kinetics, and Computational Studies. Organic Letters[J]; 2022, 24(10): 1901–1906.