Patents by Inventor Raymond Cvetovich

Raymond Cvetovich 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).

  • Glycosidation route to 4"-epi-methylamino-4"-deoxyavermectin B.sub.1
    Patent number: 5399717
    Abstract: A stereocontrolled glycosidation with thiophenyl 4-(N-allyloxycarbonyl)-epi-methylamino-4-deoxyoleandrose and 5-O-allyloxycarbonyl avermectin B.sub.1 monosaccharide using N-iodosuccinimide produces exclusively the .alpha.-anomer of a precursor of 4"-epi-methylamino-4"-deoxyavermectin B.sub.1 in 90% yield. Deprotection and crystallization as the benzoic acid salt yields 4"-epi-methylamino-4"-deoxyavermectin B.sub.1 (emamectin benzoate), a potent insecticide.
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: March 21, 1995
    Assignee: Merck & Co., Inc.
    Inventors: Raymond Cvetovich, Mallory F. Loewe
  • Stable solvates of avermectin compounds
    Patent number: 5380838
    Abstract: There is disclosed a novel form of avermectin compounds wherein the avermectin compounds are crystallized as alcohol solvates to greatly enhance stability of the avermectin drug during long-term storage. The avermectin compounds have utility as highly potent antiparasitic, insecticidal, and anthelmintic agents and compositions for that use are also disclosed.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: January 10, 1995
    Assignee: Merck & Co. Inc.
    Inventors: Joseph S. Amato, Raymond Cvetovich
  • Process for 4"-EPI-acetylamino-4"-deoxy-5-oximinoavermectin-B.sub.1
    Patent number: 5362862
    Abstract: An improved process for formation of a 5-oxime on avermectin derivatives comprises the treatment of the oxo compound with O-(trimethylsilyl)hydroxylamine in the presence of a Lewis acid.
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: November 8, 1994
    Assignee: Merck & Co., Inc.
    Inventors: Joseph S. Amato, Raymond Cvetovich
  • Process for the preparation of 4"-amino avermectin compounds
    Patent number: 5362863
    Abstract: A 4"-oxoavermectin intermediate is reductively aminated using hexa- or heptamethyldisilazane and sodium borohydride to produce a 4"-amino (or methylamino)avermectin. The 4"- aminoavermectin is a useful intermediate in the preparation of N-acyl derivatives. The compounds are useful as agricultural and animal health insecticides and parasiticides.
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: November 8, 1994
    Assignee: Merck & Co., Inc.
    Inventor: Raymond Cvetovich
  • Stable salts of 4"-deoxy-4"-epi-methylamino avermectin Bla/Blb
    Patent number: 5288710
    Abstract: Certain salts of 4"-deoxy-4"-epi-methylamino avermectin Bla/Blb such as: the benzoic acid salt, gallic acid salt, citric acid salt, benzenesulfonic acid salt and salicyclic acid salt, phosphoric acid salt, tartaric acid salt or maleic acid salt, exhibit enhanced stability, a property which serves to provide greater shelf life and a product of greater safety for the user and the environment.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: February 22, 1994
    Assignee: Merck & Co., Inc.
    Inventor: Raymond Cvetovich
  • Cyclization process for synthesis of a beta-lactam carbapenem intermediate
    Patent number: 5037974
    Abstract: A process is described for the synthesis of 3(S)-4(R)-3-[1(S)-hydroxyethyl]-4-(alkoxycarbonylmethyl)-azetidin-2-one (II) which is a useful intermediate in the synthesis of carbapenem antibiotics.
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: August 6, 1991
    Assignee: Merck & Co., Inc.
    Inventors: Mallory F. Loewe, Raymond Cvetovich, George G. Hazen