Remarkable regioselectivities in the course of the synthesis of two new Luotonin A derivatives

Mohamed Atia, Dóra Bogdán, Maryam Brügger, Norbert Haider, P. Mátyus

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12 Citations (Scopus)

Abstract

Ethyl 4-oxo-3,4-dihydroquinazoline-2-carboxylate reacts selectively with trimethylaluminium-activated 2-amino- or 4-aminobenzoic acid ethyl esters to give the corresponding anilides without self-condensation of the aminobenzoate building blocks. After propargylation, the quinazolinones were treated with Hendrickson's reagent, but only the para-substituted ester was found to undergo the expected [4 + 2] cycloaddition reaction, affording a new Luotonin A derivative. A different regioselectivity was observed with the ortho-substituted ester which affords a benzoxazinone under identical conditions. When the ester group in the ortho-substituted intermediate is replaced with a nitrile function, the outcome of the reaction with Hendrickson's reagent depends on the absence or presence of a base (DBU), yielding either a triphenylphosphonium-substituted iminobenzoxazine or a 4-cyano-substituted Luotonin A derivative.

Original languageEnglish
Pages (from-to)3231-3239
Number of pages9
JournalTetrahedron
Volume73
Issue number23
DOIs
Publication statusPublished - Jan 1 2017

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Keywords

  • Cycloaddition
  • Hendrickson's reagent
  • Luotonin A
  • Weinreb amidation

ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

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