Condensed heterocyclic ketone derivatives and their use

A compound of the formula:

• ##STR1768## wherein R.sup.1 is H, an optionally substituted hydrocarbon group or an optionally substituted acyl group;
• ring A is an optionally substituted benzene ring;
• n is a whole number of 1 to 10;
• R.sup.2, R.sup.3 and R.sup.4 are independently H or an optionally substituted hydrocarbon group, provided one of R.sup.3 and R.sup.4 is H or a straight-chain or branched C.sub.1-4 alkyl group and the other is a straight-chain or branched C.sub.1-4 alkyl group, a phenyl-C.sub.1-3 alkyl group or a naphthyl-C.sub.1-3 alkyl group;
• the R.sup.2 's may be different from one another in the repetition of n;
• k is a whole number of 0 to 3;
• and m is a whole number of 1 to 8;
• provided that when k=0 and m=2, n is a whole number of not less than 2;
• and provided that k+m=2 to 5;
• or a pharmaceutically acceptable salt thereof.

A method of treating a disease caused by acetylcholinesterase activity which comprises administering a therapeutically effective amount of a compound of the formula:

• ##STR1769## wherein X.sup.1 is R.sup.1 --N (R.sup.1 is H, an optionally substituted hydrocarbon group or an optionally substituted acyl group);
• ring A is an optionally further substituted benzene ring;
• n is a whole number of 1 to 10;
• R.sup.2, R.sup.3 and R.sup.4 are independently H or an optionally substituted hydrocarbon group;
• R.sup.3 and R.sup.4 may form an optionally substituted heterocyclic group, taken together with the adjacent nitrogen atom;
• R.sup.2 's may be different from one another in the repetition of n;
• k is a whole number of 0 to 3;
• and m is a whole number of 1 to 8, and provided that k+m=2 to 5;
• or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable carrier to a mammal suffering from such disease.