Reactions of 4-hydroxycoumarin with heterocyclic aldehydes

Renáta Gašparová,Katarína Kotlebová,Margita Lácová

doi:10.36547/nbc.1146

Abstract

Reactions of 4-hydroxycoumarin 1 with heterocyclic aldehydes 2-4 led to bis-4-hydroxycoumarin derivatives 5-7 under microwave irradiation as well as under the classical heating. The subsequent reactions of products 5-7 are described. 4,4’-Epoxydicoumarins 8, 9 were prepared by the reaction of 5-7 in acetic acid / p-toluenesulfonic acid medium. Compound 10 was prepared by the reaction of 5 in acetic anhydride in the presence sodium acetate. Dioxocine-1,15-dione 11 was prepared by the reaction of 6 with dichloromethane in sodium hydroxide-toluene.

Highlights

4-Hydroxycoumarin 1 reacts with aromatic or aliphatic aldehydes to give bis-4hydroxycoumarin derivatives (GIOVANI et al, 1991; MANOLOV et al, 2006; MAO et al, 2002), which are interesting for their biological activity and they can serve as intermediates for synthesis of various heterocycles (HAMDI et al, 2008; YAMASHITA et al, 1987)
Reaction of 1 with 6-substituted 4-oxo-4H-chromene-3-carbaldehydes 2 led to bis(4-hydroxy-2-oxo-2H-chromen-2-ones 5 in 79-81% yields after 3.5h of heating
The effect of microwave irradiation was manifested in the remarkable shortening of reaction time from 51-93 h under classical heating to 1.5h in microwave oven

Summary

Introduction

Coumarins are biologicaly active compounds with antifungal, antineoplastic, antibacterial, spasmolytic or cytotoxic activity (STANCHEV et al, 2007; JUNG et al, 2004). 4-Hydroxycoumarin 1 and its derivatives, e.g. warfarin and dicoumarol are known as anticoagulants. 4-Hydroxycoumarin 1 reacts with aromatic or aliphatic aldehydes to give bis-4hydroxycoumarin derivatives (GIOVANI et al, 1991; MANOLOV et al, 2006; MAO et al, 2002), which are interesting for their biological activity and they can serve as intermediates for synthesis of various heterocycles (HAMDI et al, 2008; YAMASHITA et al, 1987)

Experimental

General procedure for 5 and 6

General procedure for 8 and 9

Results and discussion

Conclusions