|Title:|| Process for the preparation of purine derivatives|
|Abstract:||The present invention provides a process for the synthesis of penciclovir and famciclovir by 9-substituting the compound 2-amino-6-chloropurine (ACP) with 2-acetoxymethyl-4-(leaving group)-but-1-yl acetate, followed by displacement of the 6-chloro moiety with a hydroxy moiety (i.e. to form a guanine derivative) or with hydrogen (to form the 2-aminopurine derivative), respectively.|
|Inventor(s):|| Geen; Graham Richard (Stansted Mountfitchet, GB2), Jarvest; Richard Lewis (Surbiton, GB2) |
|Assignee:|| Beecham Group plc (Brentford, GB) |
|Filing Date:||Jun 10, 1994|
|Claims:||1. A process for the preparation of i) penciclovir or ii) famciclovir which process comprises the reaction of 2-amino-6-chloropurine with 2-acetoxymethyl-4-(leaving group)-but-1-yl acetate; |
to give 9-(4-acetoxy-3-acetoxymethylbut-1-yl)-2-amino-6-chloropurine;
i) hydrolysing to give penciclovir:
ii) reducing to give famciclovir.
2. A process according to claim 1 wherein the leaving group is halo.
3. A process according to claim 2 wherein the halogen is chlorine.
4. A process according to claim 2 wherein the halogen is bromine.
5. A process according to claim 2 wherein the halogen is iodine.