| abstract |
These compounds are useful for the treatment and prevention of degenerative diseases of the central nervous system such as Alzheimer's, pugilistic dementia and Down syndrome. Claim 1: A compound of the general formula (1) wherein R 1 is -C (O) O-lower alkyl, cyano or is hetaryl; Hetaryl is a five or six link heteroaryl group, optionally substituted by R '; R 'is halogen, lower alkyl, lower alkyl substituted by halogen, lower alkoxy or lower alkoxy substituted by halogen; R2 is hydrogen, lower alkoxy, lower alkyl, halogen or cyano; R3 is - (CH2) nC (O) O-lower alkyl, lower alkyl, lower alkoxy, hydroxy, -O-Si (CH3) 2-lower alkyl, -C (O) -N (lower alkyl) 2, -OS (O) 2-lower alkyl, C 3-7 cycloalkyl, S (O) 2-aryl, heterocyclyl, -C (O) -heterocyclyl, or is aryl or heteroaryl, said aryl or heteroaryl rings are optionally substituted by one or more R '; R4 is hydrogen, lower alkyl, hydroxy or CH2CN; X is S or -N = C (R5) -; R5 is hydrogen, lower alkyl or hydroxy, Y is a bond, -O-, -CH2-, -CH2-CH2-, formula (2) or -N (R) -, R is hydrogen, lower alkyl, C (O ) O-lower alkyl, C (O)-lower alkyl, S (O) 2-lower alkyl or benzyl; n is the number 0 or 1; or its pharmaceutically active acid addition salts. |