On the peculiar reactivity of a C,N-annelated isoindole core

Authors

IAROSLAV BAGLAI
VALERIE MARAVAL
ZOIA VSEVOLODIVNA VOITENKO
CARINE DUHAYON
YULIAN MIHAILOVICH VOLOVENKO
REMI CHAUVIN

DOI

10.3906/kim-1306-58

Abstract

C-, N-, and/or O-methylation products were generated from 11H-isoindolo[2,1-a]quinazoline-5-one upon treatment with NaH followed by iodomethane under air, and possible recrystallization from methanol. Two products were fully characterized by NMR and X-ray diffraction analysis. In accordance with the HSAB principle, this soft methylating agent (MeI) leads mainly to the C,C-dimethylated product 11,11-dimethyl-11H-isoindolo[2,1-a]quinazoline-5-one, which was previously not observed, beside the N-methylated product, in a procedure using methyl tosylate as a hard methylating agent of the same substrate in the initial absence of a base. A mechanism is finally proposed for the formation of methyl 2-(3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)benzoate as an oxidation side product.

Keywords

Isoindoles, methylation processes, oxidative ring opening, quinazolines

First Page

121

Last Page

126

Recommended Citation

BAGLAI, IAROSLAV; MARAVAL, VALERIE; VOITENKO, ZOIA VSEVOLODIVNA; DUHAYON, CARINE; VOLOVENKO, YULIAN MIHAILOVICH; and CHAUVIN, REMI (2014) "On the peculiar reactivity of a C,N-annelated isoindole core," Turkish Journal of Chemistry: Vol. 38: No. 1, Article 12. https://doi.org/10.3906/kim-1306-58
Available at: https://journals.tubitak.gov.tr/chem/vol38/iss1/12