Amidoalkylation of Phosphorus Trichloride with Acetamide and Functionalized Cyclic Ketones-Evidence of Dominating Role of Side-Reactions

Abstract

The course of the reaction between phosphorus trichloride, acetamide and ethyl oxoalkanecarboxylates was studied in terms of the production of side-products. When ethyl 2-oxocycloalkane- and 4-oxocyclohexanecarboxylates were used as substrates, not only mixtures of the expected products—aminophosphonocycloalkanecarboxylic acids and their ethyl esters but also the formation of three side-products, namely 1-aminocycloalkanephosphonic acids (products of decarboxylation of the latter ones) and 1-aminoethane-1,1-diphosphonic and 1-hydroxyethane-1,1diphosphonic acids (products of the reaction of substrate and solvent with phosphonylating agent) were observed. Ethyl 2-oxo-cyclooctanecarboxylate afforded the expected 2-amino-2-pohosphonocyclooctanecarboxylic acid in minute amounts. For comparison reactions of 1-butyloxocarbonyloxopiperidines afforded the desired aminopiperidinephosphonic acids in good yields and without formation of side-products.

GRAPHICAL ABSTRACT

Keywords:

• Phosphonic analogues aspartic and glutamic acids
• aminophosphonates
• Oleksyszyn-Soroka reaction
• side products

Additional information

Funding

This work was supported by Polish Ministry of Science and Higher Education.