Reinvestigating the Synthesis and Characterization of Ethyl 3-[5-(2-Ethoxycarbonyl-1-methylvinyloxy)-1-methyl-1 H-indol-3-yl]-but-2-enoate

Nan-Sheng Li; Joseph A Piccirilli; Geoffrey L Greene

doi:10.1021/acsomega.3c03686

Reinvestigating the Synthesis and Characterization of Ethyl 3-[5-(2-Ethoxycarbonyl-1-methylvinyloxy)-1-methyl-1 H-indol-3-yl]-but-2-enoate

ACS Omega. 2023 Aug 24;8(35):31941-31945. doi: 10.1021/acsomega.3c03686. eCollection 2023 Sep 5.

Authors

Nan-Sheng Li^{1

2}, Joseph A Piccirilli^{2

3}, Geoffrey L Greene^{1

2}

Affiliations

¹ Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago Illinois 60637, United States.
² Department of Biochemistry & Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago Illinois 60637, United States.
³ Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago Illinois 60637, United States.

Abstract

We reinvestigated the reported method for the synthesis of ethyl 3-[5-(2-ethoxycarbonyl-1-methylvinyloxy)-1-methyl-1H-indol-3-yl]-but-2-enoate (MIBE), which was obtained by the reaction of 5-hydroxy-1-methyl-1H-indole with excess ethyl acetoacetate catalyzed by indium(III) chloride. Based on the NMR and MS data, we assigned the structure of the isolated product as (3E)-3-(2-ethoxy-2-oxoethylidene)-1,2,3,4-tetrahydro-7-hydroxy-1,4-dimethylcyclopent[b]indole-1-acetate (2a) rather than the reported MIBE.