A Practical Pilot-Scale Synthesis of 4-Vinyl-2,3-dihydrobenzofuran Using Imidate Ester Chemistry and Phase-Transfer Catalysis

详细信息    查看全文

• 作者：Meena Rao ; Ming Yang ; Daniel Kuehner ; John Grosso ; and Rajendra P. Deshpande
• 刊名：Organic Process Research & Development
• 出版年：2003
• 出版时间：July 2003
• 年：2003
• 卷：7
• 期：4
• 页码：547 - 550
• 全文大小：62K
• 年卷期：v.7,no.4(July 2003)
• ISSN：1520-586X

文摘

A two-step telescoped synthesis of 4-vinyl-2,3-dihydrobenzofuran (2) was demonstrated using imidate ester chemistry andphase-transfer catalysis. Treatment of 2,3-bis(2-hydroxyethyl)phenol (1) with the Vilsmeier reagent resulted in an in situgeneration of a bis-imidate intermediate 4, which was convertedto 4-(2-chloroethyl)-2,3-dihydrobenzofuran (6) via a sequentialring closure and chloride displacement reactions. Furtherdehydrohalogenation of 6 using a phase-transfer catalystprovided an excellent, cost-effective method to prepare highquality 4-vinyl-2,3-dihydrobenzofuran (2). The yields for thetwo-step telescoped process ranged from 83 to 90%.