Pliva, Farmaceutska, Kemijska, Prehrambena I Kozmeticka Industrija,

Glaxosmithkline Istrazivacki Centar Zagreb D.o.o.

Zrinka Ivezic

Antun Hutinec

Mladen Trkovnik

Sulejman Alihodzic

Nedjeljko Kujundzic

Andrea Fajdetic

Ljerka Polak

Zeljko Kelneric

The present invention relates to novel hydroxy and polyhydroxy derivatives of coumarin fused with dialdehydes and aldehyde acids of the general formulae I, II, III and IV: ##STR1## wherein R.sup.1 =R.sup.2 =4-hydroxycoumarin;

Hydroxy and polyhydroxy derivatives of coumarin, preparation thereof and

The present invention relates to novel coumarin quinolone carboxylic acids wherein the pyridone system is fused in 3,4-, 6,7- and 7,8-positions of the coumarin system, of the general formula I ##STR1## wherein R.sup.1 R.sup.2 =--NHCH=C(CO.sub.2 R.sup.6)CO, R.sup.3 =NO.sub.2 or NH.sub.2, R.sup.4 =R.sup.5 =H, R.sup.6 =H or C.sub.2 H.sub.5 ;

Certain 4H-�1!benzopyrano�3,4-b!pyridine derivatives and their

The present invention relates to new coumarin derivatives represented by the general formula I ##STR1## wherein R.sup.1 =NH.sub.2 or --NHCH.dbd.C(CO.sub.2 C.sub.2 H.sub.5).sub.2, R.sup.2 =R.sup.3 =R.sup.4 =H, R.sup.5 =F,

Coumarin derivatives, and processes for their preparation

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Zagreb, Croatia

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