# Eco-Friendly Synthesis of 2-Styryl-benzo[d][1,3]oxazin-4-ones from N-Cinnamoyl-Anthranilic Acids

## TL;DR

This paper presents a green, efficient method to synthesize 2-styryl-benzo[d][1,3]oxazin-4-ones from N-cinnamoyl-anthranilic acids using eco-friendly solvents and no metal catalysts.

## Contribution

A novel, metal-free, and chromatography-free synthesis method for 2-styryl-benzo[d][1,3]oxazin-4-ones using green chemistry principles.

## Key findings

- N-cinnamoyl anthranilic acids are synthesized efficiently using the mixed carbonic anhydride method.
- The final products are obtained without the need for chromatographic purification.
- The method uses green solvents and avoids metal catalysts and reflux conditions.

## Abstract

N-cinnamoyl anthranilic acids are synthesized in a single, eco-friendly step by condensing various cinnamic acids with free 2-aminobenzoic acid derivatives using the mixed carbonic anhydride method. Subsequently, converting the resulting N-cinnamoyl anthranilic acids into their corresponding mixed carbonic anhydrides rapidly and efficiently affords 2-styryl-benzo[d][1,3]oxazin-4-ones. The method employs green solvents, such as acetone and 2-methyltetrahydrofuran; does not require metal catalysts or reflux conditions; and yields the desired final products without chromatographic purification.