Work

Cyclization Modes in Anilides of N-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions

Year: 2024

Type: article

Abstract: Anilides of 3-oxo-4-phenylaminobutyric acid with Troc or COOEt protection at the phenylamino group undergo competing cyclization processes in neat polyphosphoric acid at 80 °C. Depending on the protecting group and the duration of the process, three main products in different ratios are formed. Along with the quinolin-2-ones, resulting from the classic Knorr cyclization, an indole derivative and a spirocyclic product have also been obtained from the COOEt-protected substrate. It has been demonstrated that the obtained indole derivative is capable of further dearomative spirocyclization under the studied conditions.

Source: Molbank

DOI: 10.3390/m1933

Authors: Plamen Angelov, Yordanka Mollova-Sapundzhieva

Institution: Plovdiv University

Language: English

Topic: Synthesis of Indole Derivatives

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $568

Funders: European Commission, Bulgarian National Science Fund