Abstract: The present invention relates to compounds of formula ##STR1## in which formula I X stands for O, S, ##STR2## R.sub.1 and R.sub.2 which can be the same or different stand for hydrogen, straight or branched, saturated or unsaturated, unsubstituted or substituted C.sub.1- C.sub.8 -alkyl, aryl or for ar-C.sub.1 -C.sub.4 -alkyl, aryl and ar being unsubstituted or substituted phenyl; R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are the same or different and stand for hydrogen, halogen, pseudo halogen, cyano, nitro, amino, carboxy, hydroxy, alkyl, alkoxy; or R.sub.5 and R.sub.6 form an aromatic ring which is fused to the pyridyl ring, and which aromatic ring may substituted; provided that R.sub.1 and R.sub.2 cannot be hydrogen at the same time, and provided that when R.sub.5 and R.sub.6 both are chlorine and R.sub.1 is hydrogen, then R.sub.2 cannot be n-propyl; and salts and bioreversible derivatives thereof.

Abstract: The present invention relates to hitherto unknown compounds of formula, in which formula R.sub.1 stands for hydrogen, straight or branched, saturated or unsaturated, unsubstituted or substituted C.sub.1 --C.sub.8 --alkyl, aryl or for ar--C.sub.1 --C.sub.4 --alkyl, aryl or an being unsubstituted or substituted phenyl, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are the same or different and stand for hydrogen, halogen, pseudo halogen, cyano, nitro, amino, carboxy, carbalkoxy, carbamyl, hydroxy, alkyl, alkoxy; n and m are the same or different and stand for an integer from 0-6; provided that n cannot be zero when A stands for carboxy and X and Q both stand for a bond; X stands for a bond or for O, S, S(O), S(O).sub.2 or for NR.sub.8 where R.sub.8 is defined as R.sub.1 above; Q stands for a bond of for straight or branched, C.sub.1 --C.sub.6 --alkylene; A stands for an acidic group, e.g.

Abstract: The present invention relates to compounds of formula ##STR1## in which formula I X stands for O, S, ##STR2## R.sub.1 and R.sub.2 which can be the same or different stand for hydrogen, straight or branched, saturated or unsaturated, unsubstituted or substituted C.sub.1 -C.sub.8 -alkyl, aryl or for ar-C.sub.1 -C.sub.4 -alkyl, aryl and ar being unsubstituted or substituted phenyl; R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are the same or different and stand for hydrogen, halogen, pseudo halogen, cyano, nitro, amino, carboxy, hydroxy, alkyl, alkoxy; or R.sub.5 and R.sub.6 form an aromatic ring which is fused to the pyridyl ring, and which aromatic ring may substituted; provided that R.sub.1 and R.sub.2 cannot be hydrogen at the same time, and provided that when R.sub.5 and R.sub.6 both are chlorine and R.sub.1 is hydrogen, then R.sub.2 cannot be n-propyl; and salts and bioreversible derivatives thereof.

Abstract: The present invention relates to compounds of formula I ##STR1## in which formula I X stands for O, S, ##STR2## R.sub.1 and R.sub.2 which can be the same or different stand for hydrogen, straight or branched, saturated or unsaturated, unsubstituted or substituted C.sub.1 -C.sub.8 -alkyl, or for ar-C.sub.1 -C.sub.4 -alkyl, aryl and ar being unsubstituted or substituted phenyl; R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are the same or different and stand for hydrogen, halogen, pseudo halogen, cyano, nitro, amino, carboxy, hydroxy, alkyl, alkoxy; or R.sub.5 and R.sub.6 form an aromatic ring which is fused to the pyridyl ring, and which aromatic ring may substituted; provided that R.sub.1 and R.sub.2 cannot be hydrogen at the same time, and provided that when R.sub.5 and R.sub.6 both are chlorine and R.sub.1 is hydrogen, then R.sub.2 cannot be n-propyl; and salts and bioreversible derivatives thereof.