# Original Synthesis of Substituted 6H-Benzo[c]chromene Derivatives Using a TDAE and Pd-Catalyzed Cyclization Strategy

## TL;DR

A new method was developed to efficiently synthesize 6H-benzo[c]chromene derivatives using a two-step process involving TDAE and palladium catalysis.

## Contribution

The paper introduces a novel synthetic strategy combining TDAE and Pd-catalyzed cyclization for substituted 6H-benzo[c]chromene derivatives.

## Key findings

- A TDAE-initiated reaction successfully produced substituted 1-(2′-bromo-[1,1′-biphenyl]-2-yl)-2-phenylethanols.
- Palladium-catalyzed intramolecular O-arylation under microwave irradiation completed the synthesis of 6H-benzo[c]chromene derivatives.
- X-ray crystallography confirmed the structure of one of the synthesized derivatives (product 5c).

## Abstract

We report an efficient synthetic method for the preparation of 6H-benzo[c]chromenes from substituted 1-(2′-bromo-[1,1′-biphenyl]-2-yl)-2-phenylethanols. These intermediates were obtained via a TDAE-initiated reaction between new substituted 2′-bromo-[1,1′-biphenyl]-2-carbaldehyde derivatives and substituted nitrobenzylic chlorides. The second step involved a palladium-catalyzed intramolecular O-arylation of the alcohol intermediate under microwave irradiation (110 °C for 1.5 h). The structure of 6H-benzo[c]chromene derivatives was confirmed by X-ray crystallography of product 5c.