Patents by Inventor John Christopher Hanson

John Christopher Hanson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Preparation of penciclovir or famciclovir
    Patent number: 6093819
    Abstract: A process for preparing 2-amino-6-chloropurine or a 2-acylated derivative thereof, comprising reacting guanine or 2,9-diacylguanine with a chlorinating agent, in the presence of methyltriethylammonium chloride as phase transfer catalyst, and thereafter when necessary, removing the 9-acyl group by hydrolysis.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: July 25, 2000
    Assignee: SmithKline Beecham plc
    Inventor: John Christopher Hanson
  • Pharmaceuticals preparation of 2-amino-6-chloropurine with TEMAC
    Patent number: 5910589
    Abstract: A process for preparing a 2-amino-6-chloropurine or a 2-acylated derivative thereof, comprising reacting guanine or 2,9-diacylguanine with a chlorinating agent, in the presence of methyltriethylammonium chloride as phase transfer catalyst, and thereafter when necessary, removing the 9-acyl group by hydrolysis.
    Type: Grant
    Filed: March 21, 1995
    Date of Patent: June 8, 1999
    Assignee: SmithKline Beecham p.l.c.
    Inventor: John Christopher Hanson