New Easy Approach to the Synthesis of 2,5-Disubstituted and 2,4,5-Trisubstituted 1,3-Oxazoles. The Reaction of 1-(Methylthio)acetone with Nitriles
作者:Antonio Herrera、Roberto Martínez-Alvarez、Pedro Ramiro、Dolores Molero、John Almy
DOI:10.1021/jo052619v
日期:2006.4.1
The reaction of 1-(methylthio)acetone with different nitriles in the presence of triflic anhydride led to the one-pot formation of 2-substituted 5-methyl-4-methylthio-1,3-oxazoles in good yield. 1,2- and 1,4-Bisozaxolyl-substituted benzenes were obtained when the reaction was carried out using aromatic dinitriles. The methylthio group at the C4 position of the oxazole ring was easily removed with Raney
1-(甲硫基)丙酮在三氟甲磺酸酐存在下与不同腈的反应以高收率单锅形成2-取代的5-甲基-4-甲硫基-1,3-恶唑。当使用芳族二腈进行反应时,获得1,2-和1,4-二异氮杂甲苯基取代的苯。用阮内镍很容易地除去恶唑环的C4位上的甲硫基,以高收率形成2-取代的5-甲基-1,3-恶唑。通过用m- CPBA氧化MeS基团来制备4-甲基磺酰基衍生物。所提出的恶唑形成机理涉及不稳定的1-(甲硫基)-2-氧丙基三氟甲磺酸酯,其是从低温NMR光谱中检测到的。