Patents by Inventor John K. Thottathil

John K. Thottathil 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).

  • Patent number: 4734508
    Abstract: A process is provided for preparing 4-hydroxy-4-phenyl-proline derivatives of the structure ##STR1## wherein R.sub.1 is a nitrogen protecting group such as benzoyl, benzyloxycarbonyl, t-butoxycarbonyl, benzyl, benzhydryl, trityl, acetyl, trifluoromethylacetyl, sulfonamides, and the like and wherein X is OR.sub.2 and R.sub.2 is hydrogen or an acid protecting group such as lower alkyl, aryl-lower alkyl or a metal ion, such as Na or K, or X is NR.sub.3 R.sub.4 wherein R.sub.3 and R.sub.4 may be the same or different and are hydrogen, lower alkyl, aryl or arylalkyl, or R.sub.3 and R.sub.4 together with the nitrogen to which they are attached form a 5-, 6- or 7-membered ring. The process includes the steps of forming triphenylcerium [(C.sub.6 H.sub.5).sub.3 Ce], for example, by reacting cerium trichloride (CeCl.sub.3) with phenyllithium, and reacting the triphenylcerium with the keto acid ##STR2## in the presence of an inert organic solvent such as tetrahydrofuran.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: March 29, 1988
    Assignee: E. R. Squibb & Sons, Inc.
    Inventor: John K. Thottathil
  • Patent number: 4687865
    Abstract: A process is provided for preparing a 7-oxabicycloheptane amino alcohol intermediate of the general structure ##STR1## (wherein the above structures represents (D) or (L) isomers) which is useful in preparing thromboxane A.sub.2 receptor antagonists. This intermediate is prepared by reacting mesoanhydride with an aryl amine ##STR2## wherein R is alkyl, CH.sub.2 OH, CO.sub.2 H or CO.sub.2 alkyl, to form the acid ##STR3## which is reduced by treatment with lithium aluminum hydride or diisobutylaluminum hydride or Red-Al to form the alcohol ##STR4## wherein R.sup.1 is CH.sub.2 OH when R is CO.sub.2 H, CO.sub.2 alkyl or CH.sub.2 OH, and R.sup.1 is alkyl when R is alkyl; where in the above alcohol R.sup.1 is CH.sub.2 OH, such alcohol compound is treated with an alkyl chloroformate in the presence of base such as an alkali metal alkoxide to form the alcohol ##STR5## which undergoes cleavage by treatment with alkali metal, ammonia and acid to form the amino alcohol intermediate.Where in the above alcohol R.sup.
    Type: Grant
    Filed: June 4, 1986
    Date of Patent: August 18, 1987
    Assignee: E. R. Squibb & Sons, Inc.
    Inventor: John K. Thottathil
  • Patent number: 4670193
    Abstract: A process for preparing phosphonic acids of the structure ##STR1## wherein R.sub.1 is lower alkyl, aryl, cycloalkyl or arylalkyl, and R.sub.2 is H, benzyl or ##STR2## by oxidizing the corresponding phosphonous acid ##STR3## employing as the oxidizing agent potassium permanganate or sodium periodate.
    Type: Grant
    Filed: May 12, 1986
    Date of Patent: June 2, 1987
    Assignee: E. R. Squibb & Sons, Inc.
    Inventor: John K. Thottathil
  • Patent number: 4625038
    Abstract: Disclosed herein are novel chemical intermediates having the formula ##STR1## wherein R.sub.1 is alkyl, cycloalkyl, aryl or arylalkyl.
    Type: Grant
    Filed: December 23, 1985
    Date of Patent: November 25, 1986
    Assignee: E. R. Squibb & Sons, Inc.
    Inventor: John K. Thottathil
  • Patent number: 4602092
    Abstract: A method is provided for preparing phosphinic acid prodrug intermediates which are useful in preparing phosphinic acid angiotensin-converting enzyme inhibitors which method includes the step of coupling a phosphonous acid or its ester of the structure ##STR1## wherein R is H or lower alkyl and R.sup.1 is lower alkyl, aryl, arylalkyl, cycloalkyl or cycloalkylalkyl, with an alkylating agent of the structure ##STR2## wherein Hal is Cl, Br or I, n is 0 or 1, R.sup.2 is H or lower alkyl, and Z is H, lower alkyl, --CO.sub.2 R.sup.3 (wherein R.sup.3 is H or lower alkyl), ##STR3## (wherein R.sup.4 is H, lower alkyl, aryl or arylalkyl), --CN, or ##STR4## (wherein R.sup.5 and R.sup.6 may be the same or different and are selected from the group consisting of H, lower alkyl, aryl, aryl-lower alkyl, cycloalkyl or cycloalkylalkyl and at least one of R.sup.5 and R.sup.6 is other than H, or R.sup.5 and R.sup.
    Type: Grant
    Filed: January 22, 1985
    Date of Patent: July 22, 1986
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: John K. Thottathil, Jerome L. Moniot
  • Patent number: 4594199
    Abstract: A method is provided for preparing phosphinic acid prodrug intermediates which are useful in preparing phosphinic acid angiotensin-converting enzyme inhibitors which method includes the step of coupling a phosphonous acid or its ester of the structure ##STR1## wherein R is H or lower alkyl and R.sup.1 is lower alkyl, aryl, arylalkyl, cycloalkyl or cycloalkylalkyl, with a conjugated compound of the structure ##STR2## wherein R.sup.2, R.sup.3 and R.sup.4 may be the same or different and each is independently H, lower alkyl or aryl, and Z is --CO.sub.2 R.sup.5 (wherein R.sup.5 is H or lower alkyl), ##STR3## (wherein R.sup.6 is H, lower alkyl aryl or arylalkyl), ##STR4## (wherein R.sup.7 and R.sup.8 are the same or different and are selected from the group consisting of H, lower alkyl, aryl, aryl-lower alkyl, cycloalkyl or cycloalkylalkyl and at least one of R.sup.7 and R.sup.8 is other than H, or R.sup.7 and R.sup.
    Type: Grant
    Filed: January 22, 1985
    Date of Patent: June 10, 1986
    Assignee: E. R. Squibb & Sons, Inc.
    Inventor: John K. Thottathil
  • Patent number: 4588819
    Abstract: 4-Substituted proline derivatives having the formula ##STR1## can be prepared by reacting the compound having the formula ##STR2## with a compound having the formula ##STR3## to obtain a compound having the formula ##STR4## (a novel intermediate), alkylating that compound to obtain a compound having the formula ##STR5## (a novel intermediate), converting that compound to a compound having the formula ##STR6## (a novel intermediate), and oxidizing that compound to yield the desired proline having the formula ##STR7## wherein R.sub.1 is alkyl, cycloalkyl, aryl or arylalkyl, R.sub.1 ' is alkyl, cycloalkenyl, aryl or arylalkyl, R.sub.2 is alkyl, aryl, arylalkyl or cycloalkyl and R.sub.3 is hydrogen, alkyl, aryl, arylalkyl or cycloalkyl.
    Type: Grant
    Filed: November 19, 1984
    Date of Patent: May 13, 1986
    Assignee: E. R. Squibb & Sons, Inc.
    Inventor: John K. Thottathil
  • Patent number: 4501901
    Abstract: A method is provided for making substituted prolines of the structure ##STR1## wherein X is lower alkyl or aryl, R is H, lower alkyl or an alkali metal and Z is an N-protecting group, which method includes the step of reacting a compound of the structure ##STR2## wherein Z and R are as defined above and Q is Br. tosyloxy or mesylate, with an organic copper lithium compound of the structureXYCuLiwherein X is as defined above and Y is lower alkyl, aryl or CN.Where X is phenyl, the corresponding 4-cyclohexyl compound may be produced by conventional hydrogenation techniques.The compounds produced are useful as intermediates in the preparation of phosphinic acid derivatives useful in the treatment of hypertension.
    Type: Grant
    Filed: September 19, 1983
    Date of Patent: February 26, 1985
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: John K. Thottathil, Jerome L. Moniot, David Floyd, Steven Brandt