Abstract: A compound according to formula 1 ##STR1## wherein R.sub.1 and R.sub.2 independently represent hydrogen, carbamoyl which is substituted by an alkyl of 1 to 4 carbon atoms, alkylcarbonyl of 2 to 5 carbon atoms or phenyl carbonyl, X represents halogen nitro or cyano and R.sub.3 represents ##STR2## wherein R.sub.4 represents cyano or alkylcarbonyl of 2 to 5 carbon atoms and R.sub.5 represents carbamoyl which is unsubstituted or substituted with alkyl of 1 to 8 carbon atoms or which is substituted with hydroxyalkyl of 1 to 8 carbon atoms or pharmaceutically acceptable esters and salts thereof, and a pharmaceutically acceptable carrier therefor, as well as pharmaceutical compositions containing said compounds as COMT inhibitors.

Abstract: Catechol compounds of formula I ##STR1## where R.sub.1, R.sub.2, R.sub.3 and X are as described herein are effective Catechol-O-methyltransferase inhibitors.

Abstract: The invention concerns a method for the treatment of Parkinson's Disease. The method comprises administering a catechol-O-methyl-transferase inhibiting amount of a compound having the formula I ##STR1## wherein R.sub.1 and R.sub.2 independently represent hydrogen, alkylcarbamoyl of 2 to 5 carbon atoms or alkylcarbonyl of 2 to 5 carbon atoms, X represents nitro or cyano and R.sub.3 represents ##STR2## wherein R.sub.4 represents cyano or alkylcarbonyl of 2 to 5 carbon atoms and R.sub.5 represents cyano; alkylcarbonyl of 2 to 5 carbon atoms; or carbamoyl which is unsubstituted or substituted with alkyl of 1 to 8 carbon atoms, or hydroxyalkyl of 1 to 8 carbon atoms or pharmaceutically acceptable salts or esters thereof; and a sufficient amount of levodopa to treat Parkinson's Disease. A peripheral decarboxylase inhibitor such as carbidopa or benzerazide is also preferably administered.

Abstract: Pharmacologically active catechol derivatives of formula I ##STR1## wherein R.sub.1 and R.sub.2 independently comprise hydrogen, alkyl, acyl, optionally substituted aroyl, lower alkylsulfonyl or alkylcabamoyl or taken together form a lower alkylidene or cycloalkylidene, X comprises an electronegative substituent such as halogen, nitro, cyano, lower alkylsulfonyl, sulfonamido, aldehyde, caboxyl or trifluoromethyl and R.sub.3 comprises hydrogen, halogen, hydroxy alkyl, amino, nitro, cyano, trifluoromethyl, lower alkylsulfonyl, sulfonamide, aldehyde, alkyl carbonyl, aralkylidene carbonyl or carboxyl or a group selected from ##STR2## wherein R.sub.4 comprises hydrogen, alkyl, cyano, carboxyl or acyl and R.sub.5 comprises hydrogen, cyano, carboxyl, alkoxycarbonyl, carboxyalkenyl, nitro, acyl, optionally substituted aroyl or heteroaroyl, hydroxyalkyl or carboxyalkyl or R.sub.4 and R.sub.5 together form a five to seven membered substituted cycloalkanone ring;--(CO).sub.n (CH.sub.2).sub.