Abstract: Compounds of the formula: ##STR1## where R is hydrogen, hydroxyl, alkyl or acyl, R' and R" together are oxo, hydroxyimino or alkoxyimino, and R' and R" independently are hydrogen, hydroxyl, acyloxy, or amino substituted by any of hydrogen, alkylcarbonyl, arylcarbonyl, aralkylcarbonyl, alkoxycarbonyl, aralkoxycarbonyl, alkylsulfonyl or arylsulfonyl, and n is 0 or 1, and the pharmaceutically acceptable salts thereof. The compounds are macrolide antibiotics and are also useful as intermediates to the synthesis of other macrolide antibiotics. Pharmaceutical compositions and methods of their use are also provided for.
Type:
Grant
Filed:
March 26, 1992
Date of Patent:
November 16, 1999
Assignee:
Merck & Co., Inc.
Inventors:
James V. Heck, William J. Leanza, Ronald W. Ratcliffe, Thomas N. Salzmann, Kothandaraman Shankaran, Michael J. Szymonifka, Robert R. Wilkening
Abstract: This invention provides certain carboxymethyl cellulose (CMC) esters of higher acids (e.g., CMC acetate propionate, CMC propionate, CMC acetate butyrate, and CMC butyrate). These new ether derivatives of cellulose esters exhibit solubility in a wide range of organic solvents, compatibility with a variety of resins, and ease of dispersion in a water-borne formulation and are useful in coating compositions as binder resins and rheology modifiers.
Type:
Grant
Filed:
May 22, 1997
Date of Patent:
August 11, 1998
Inventors:
John Michael Allen, Alan Kent Wilson, Paul Lee Lucas, Larry Gerald Curtis
Abstract: According to the invention the reels 10 of cellulose thread wound in a loose manner around a hollow perforated core are arranged on the nozzles 9 carried by the hollow arms 8 of a rotor 7a placed on a hollow frame 7 situated at the bottom of a tank 6. A pump 13 causes the nitrating medium 15 consisting of a mixture of nitric acid and methylene chloride to circulate into the pipe 14 from where it passes into the frame 7 and then to the rotor 7a from where it is brought under pressure via the pipes 8 and the nozzles 9 to the hollow perforated core of each reel. The nitrating medium then passes radially along the mass of thread making up each reel and returns to the pump 13 via the pipes 12. After nitration the nitrocellulose threads are immediately stabilized by washing them with water in a similar installation to that used for nitration.
Type:
Grant
Filed:
October 1, 1984
Date of Patent:
October 8, 1985
Assignee:
Societe Nationale des Poudres et Explosifs
Inventors:
Hubert Delarche, Alain Brasquies, Michel Maures
Abstract: There is disclosed a multi-vessel autoclave which is suitable for use in a continuous process for purifying nitrocellulose made by the nitric acid-sulfuric acid nitration of cellulose. The autoclave comprises a plurality of adjacent cylindrical vessels wherein each common wall between the adjacent vessels has an opening for the passage of the nitrocellulose which is in a slurry. The openings are situated so the slurry flows in a serpentine path.
Abstract: A process for purification of nitrocellulose containing residual acid from nitration is provided. In this process the nitrocellulose is cut in the presence of water to form an aqueous slurry of cut nitrocellulose fibers. The pH of the slurry is adjusted to a value of at least about 8 and the slurry is heated under pressure. The pH of the slurry is maintained above 8 during heating by addition of basic solution to the slurry. When the residual acid in the slurry is substantially completely neutralized, the fibers are separated from the slurry. The purified nitrocellulose is of reduced viscosity and satisfactory stability.
Type:
Grant
Filed:
July 23, 1980
Date of Patent:
April 6, 1982
Assignee:
Hercules Incorporated
Inventors:
William T. Bolleter, Carl D. Chandler, Jr.