Claims for Patent: 5,246,937

Summary for Patent: 5,246,937

Title:	Purine derivatives
Abstract:	The present invention provides antiviral compounds of Formula (I): ##STR1## pharmaceutical compositions prepared therefrom, and methods of treatment of viral infections therewith.
Inventor(s):	Harnden; Michael R. (Horsham, GB2), Jarvest; Richard L. (Surbiton, GB2)
Assignee:	Beecham Group p.l.c. (GB2)
Application Number:	07/824,131
Patent Claims:	1. A compound of Formula (I) ##STR19## or a pharmaceutically acceptable salt thereof, where R.sub.1 and R.sub.2 are each independently hydrogen, or a carboxylic acyl provided that R.sub.1 and R.sub.2 are not both hydrogen; or R.sub.1 and R.sub.2 are joined together to form a cyclic acetal group or a cyclic carbonate group. 2. A compound according to claim 1 wherein R.sub.1 and/or R.sub.2 is a carboxylic acyl group such that the group R.sub.1 O-- and/or R.sub.2 O-- is a pharmaceutically acceptable ester group. 3. A compound according to claim 2 wherein the carboxylic acyl group R.sub.1 and/or R.sub.2 is a group ##STR20## wherein R.sub.3 is C.sub.1-6 alkyl, C.sub.1-6 alkoxy or aryloptionally substituted with one or two groups selected from C.sub.1-6 alkyl, C.sub.1-6 alkoxy and halo. 4. A compound according to claim 1 wherein R.sub.1 and R.sub.2 are joined together to form a group ##STR21## or ##STR22## 5. A compound according to claim 4 wherein R.sub.1 and R.sub.2 are joined together as a C(CH.sub.3).sub.2 group. 6. A compound according to claim 1 selected from 2-amino-9-(4-acetoxy-3-acetoxymethylbut-1-yl)purine; 2-amino-9-(4-acetoxy-3-hydroxymethylbut-1-yl)purine; 2-amino-9-(3-hydroxymethyl-4-methoxycarbonyloxybut-1-yl)purine; 2-amino-9-[2-(2,2-dimethyl-1,3-dioxan-5-yl)ethyl]purine; 2-amino-9-(4-propionyloxy-3-propionyloxymethylbut-1-yl)purine; 2-amino-9-(4-butyryloxyl-3-hydroxymethylbut-1-yl)purine; 2-amino-9-(4-benzoyloxyl-3-hydroxymethylbut-1-yl)purine; and pharmaceutically acceptable salts thereof. 7. A pharmaceutical composition for treating viral infections which comprises a compound of formula (I) as defined in claim 1 in combination with a pharmaceutically acceptable carrier. 8. A method of treating viral infections in a human or non-human animal, which comprises administering to the animal an effective, non-toxic amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof. 9. A compound named 2-amino-9-(4-acetoxy-3-acetoxymethylbut-1-yl)purine 10. A method of treating herpesvirus infection in a human or non-human animal, which comprises administering to the animal an effective, non-toxic amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof. 11. A method of claim 10 wherein the herpesvirus is herpes simplex type 1 (HSV-1). 12. A method of claim 10 wherein the herpesvirus is herpes simplex type 2 (HSV-2). 13. A method of claim 10 wherein the herpesvirus is varicella zoster. 14. A method of claim 8 wherein the compound is 2-amino-9-(4-acetoxy-3-acetoxymethylbut-1-yl)purine. 15. A method of claim 10 wherein the compound is 2-amino-9-(4-acetoxy-3-acetoxymethylbut-1-yl)purine or a pharmaceutically acceptable salt thereof. 16. A method of claim 15 wherein the herpesvirus is herpes simplex type 1 (HSV-1). 17. A method of claim 15 wherein the herpesvirus is herpes simplex type 2 (HSV-2). 18. A method of claim 15 wherein the herpesvirus is varicella zoster. 19. A pharmaceutical composition of claim 7 wherein the compound is 2-amino-9-(4-acetoxy-3-acetoxymethylbut-1-yl)purine.