Collect. Czech. Chem. Commun.
1986, 51, 1972-1985
https://doi.org/10.1135/cccc19861972
Formation of the Meisenheimer spiro adduct of N-(2,4,6-trinitrophenyl)alanine methylamide and its rearrangement to 2-amino-N-methyl-N-(2,4,6-trinitrophenyl)propanamide
Vladimír Macháčeka, Makky M. M. Hassaniena, Vojeslav Štěrbaa and Antonín Lyčkab
a Department of Organic Chemistry, Institute of Chemical Technology, 532 10 Pardubice
b Research Institute of Organic Syntheses, 532 18 Pardubice-Rybitví
Abstract
N-(2,4,6-trinitrophenyl)alanine methylamide (I) undergoes base-catalyzed cyclization in methanol to give the spiro adduct II. In aniline-anilinium chloride buffers, the spiro adduct is protonated at the oxygen atom of 2-nitro group to give the neutral compound III. In 4-bromoaniline buffers or by action of methanolic hydrogen chloride, the compound III is opened to E and Z isomers of 2-amino-N-methyl-N-(2,4,6-trinitrophenyl)propanamide hydrochloride (IV). The rate-limiting step of cyclization of compound Z-IV to compound III consists in the isomerization Z-IV → E-IV. At higher pH values (acetate buffers), the rate-limiting step is gradually changed to the isomerization of 2-amino-N-methyl-N-(2,4,6-trinitrophenyl)propanamide (Z-V → E-V).
