Dihydropyrimidine derivatives

A compound of the formula I ##STR32## or its isomer ##STR33## or a pharmaceutically acceptable salt thereof wherein R.sub.1 is alkyl, alkenyl or alkynyl or an alkyl, alkenyl or alkynyl group substituted with F or --CO.sub.2 R.sub.7 ;

• cycloalkyl;
• (cycloalkyl)alkyl of 4 to 10 carbon atoms;
• (cycloalkyl)alkenyl or (cycloalkyl)alkynyl of 5 to 10 carbon atoms;
• --NR.sub.10 R.sub.11 ;
• --(CH.sub.2).sub.m Z(CH.sub.2).sub.m R.sub.13 ;
• benzyl or benzyl substituted with 1 or 2 halogens, alkoxy of 1 to 4 carbon atoms, alkyl of 1 to 4 carbon atoms, haloalkyl or nitro;
• --SR.sub.14 ;
• or --OR.sub.14 ;
• R.sub.2 and R.sub.3 taken together with the carbon atoms to which they are attached form an aryl group;
• R.sub.4 and R.sub.5 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, (cycloalkyl)alkyl, heterocyclo, (heterocyclo)alkyl, haloalkyl or --CO.sub.2 R.sub.7 ;
• or R.sub.4 and R.sub.5 taken together with the carbon atom to which they are attached form a 5- to 7-membered carbocyclic ring which may have another 5- to 7-membered ring fused thereoto;
• or R.sub.4 and R.sub.5 taken together with the carbon atom to which they are attached form a carbonyl or a thiocarbonyl group;
• R.sub.6 is an acid moiety such as hydrogen, ##STR34## R.sub.7 is hydrogen, alkyl, perfluoroalkyl of 1 to 8 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, phenyl, benzyl ##STR35## R.sub.8 is hydrogen, alkyl, aryl, arylalkyl or cycloalkyl;
• R.sub.9 is alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl;
• R.sub.10 and R.sub.11 are independently hydrogen, alkyl of 1 to 6 carbon atoms, benzyl, .alpha.-methylbenzyl, or taken together with the nitrogen atom to which they are attached form a ring of the formula ##STR36## R.sub.12 is hydrogen, alkyl of 1 to 6 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, phenyl or benzyl;
• R.sub.13 is hydrogen;
• alkyl of 1 to 6 carbon atoms;
• cycloalkyl;
• alkenyl or alkynyl of 2 to 4 carbon atoms;
• or the above alkyl, cycloalkyl, alkenyl or alkynyl groups optionally substituted with F or --CO.sub.2 R.sub.7 ;
• R.sub.14 is alkyl, alkenyl, alkynyl, aryl, arylalkyl, cycloalkyl, (cycloalkyl)alkyl, heterocyclo, (heterocyclo)alkyl or haloalkyl;
• R.sub.18 is hydrogen, alkyl of 1 to 5 carbon atoms or phenyl;
• R.sub.19 is --CN, --NO.sub.2 or --CO.sub.2 R.sub.7 ;
• Q is --CH.sub.2, --O--, or --NR.sub.8 ;
• Z is --O--, --S-- or --NR.sub.12 ;
• m is an integer of 1 to 5;
• and
• p is 0, or the integer 1 or 2.