Patents by Inventor Angang Wang

Angang Wang 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).

  • Publication number: 20220127270
    Abstract: The present disclosure relates, in general, to improved processes for the preparation of 4-{8-amino-3-[(2S)-1-(but-2-ynoyl)pyrrolidin-2-yl]imidazo[1,5-a]pyrazin-1-yl}-N-(pyridin-2-yl)-benzamide, particularly large-scale processes for manufacturing 4-{8-amino-3-[(2S)-1-(but-2-ynoyl)pyrrolidin-2-yl]imidazo[1,5-a]pyrazin-1-yl}-N-(pyridin-2-yl)benzamide and intermediates used in such processes.
    Type: Application
    Filed: August 28, 2019
    Publication date: April 28, 2022
    Inventors: Paul Allen BETHEL, Lai Chun CHAN, Katie Grace COOPER, Robert John COX, Michael David GOLDEN, Shaun Alan HUGHES, Lucinda Victoria JACKSON, Kirsty Jane MILLARD, Andrew John PHILLIPS, Alexander James TELFORD, Jerry EVARTS, Michael Joseph LAWLER, Remy E. J. N. LITJENS, Peter Johannes Servaas Savio VAN EIJK, Mathilda Maria Henrica VERSTAPPEN, Frank L. M. VOS, Eric Jurriƫn ZIJP, Qiu JUNYING, Rustam Ferdinand GARREY, David Allen SHORT, Angang WANG
  • Publication number: 20150353501
    Abstract: The disclosure provides a process for the preparation of alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylate and its analogs. The process includes a reaction workup method for Claisen condensation, wherein the enolate salt is acidified after removing remaining starting material and byproducts such as, ethanol and excessive ethyl acetate. The process also includes a method for completely drying alkyl difluoroacetoacetate and its analogs before use in the next step by reacting trialkyl orthoformate with the residual water. The process includes using Na2CO3 and/or K2CO3 to promote the ring-closure reaction to produce the alkyl 3-di-fluoromethyl-1-methyl-1H-pyrazole-4- carboxylate. The process also includes effectively removing the regioisomer, alkyl 3-difluoro methyl-2-methyl-1H-pyrazole-4-carboxylate formed as a byproduct of the ring closure by a precipitation in a mixed solvent system and thereby eliminating the need for recrystallization of the final product.
    Type: Application
    Filed: August 19, 2015
    Publication date: December 10, 2015
    Inventors: Zheqing Wang, Angang Wang, Yongcan Wang, Zhenwei Li
  • Patent number: 9139507
    Abstract: The disclosure provides a process for the preparation of alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-caboxylate and its analogs. The process includes a reaction workup method for Claisen condensation, wherein the enolate salt is acidified after removing remaining starting material and byproducts such as, ethanol and excessive ethyl acetate. The process also includes a method for completely drying alkyl difluoroacetoacetate and its analogs before use in the next step by reacting trialkyl orthoformate with the residual water. The process includes using Na2CO3 and/or K2CO3 to promote the ring-closure reaction to produce the alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylate. The process also includes effectively removing the regioisomer, alkyl 3-difluoromethyl-2-methyl-1H-pyrazole-4-caboxylate formed as a byproduct of the ring closure by a precipitation in a mixed solvent system and thereby eliminating the need for recrystallization of the final product.
    Type: Grant
    Filed: December 9, 2013
    Date of Patent: September 22, 2015
    Assignee: KINGCHEM LLC.
    Inventors: Zheqing Wang, Angang Wang, Yongcan Wang, Zhenwei Li
  • Publication number: 20150158808
    Abstract: The disclosure provides a process for the preparation of alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylate and its analogs. The process includes a reaction workup method for Claisen condensation, wherein the enolate salt is acidified after removing remaining starting material and byproducts such as, ethanol and excessive ethyl acetate. The process also includes a method for completely drying alkyl difluoroacetoacetate and its analogs before use in the next step by reacting trialkyl orthoformate with the residual water. The process includes using Na2CO3 and/or K2CO3 to promote the ring-closure reaction to produce the alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylate. The process also includes effectively removing the regioisomer, alkyl 3-difluoromethyl-2-methyl-1H-pyrazole-4-carboxylate formed as a byproduct of the ring closure by a precipitation in a mixed solvent system and thereby eliminating the need for recrystallization of the final product.
    Type: Application
    Filed: December 9, 2013
    Publication date: June 11, 2015
    Inventors: Zheqing Wang, Angang Wang, Yongcan Wang, Zhenwei Li
  • Patent number: 8871947
    Abstract: The present disclosure provides a novel and economically advantageous process for preparation of compounds of Formula I, such as alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid ester. The process includes acidification of the sodium enolate of alkyl difluoroacetoacetate by carbonic acid generated in situ by reacting carbon dioxide with water. The disclosure also includes promoting the ring closure reaction in which alkyl 2-alkomethylene-4,4-difluoro-3-oxobutyrate is reacted with methylhydrazine in two phase system with a weak base such as Na2CO3 or K2CO3.
    Type: Grant
    Filed: December 31, 2013
    Date of Patent: October 28, 2014
    Assignee: KingChem LLC
    Inventors: Zheqing Wang, Angang Wang
  • Publication number: 20140221669
    Abstract: The present disclosure provides a novel and economically advantageous process for preparation of compounds of Formula I, such as alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid ester. The process includes acidification of the sodium enolate of alkyl difluoroacetoacetate by carbonic acid generated in situ by reacting carbon dioxide with water. The disclosure also includes promoting the ring closure reaction in which alkyl 2-alkomethylene-4,4-difluoro-3-oxobutyrate is reacted with methylhydrazine in two phase system with a weak base such as Na2CO3 or K2CO3.
    Type: Application
    Filed: December 31, 2013
    Publication date: August 7, 2014
    Inventors: Zheqing Wang, Angang Wang