Patents by Inventor Wenfeng Huang
Wenfeng Huang 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).
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Publication number: 20240092729Abstract: The present invention relates to a method for purifying key intermediates of Citalopram, i.e. 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile and a salt thereof. The method comprises dissolving crude 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile (compound of formula I containing formaldehyde impurity) with an organic solvent, adding a washing solution, controlling the temperature, stirring, leaving to stand for layering, and removing the aqueous layer, so as to obtain a purified organic solution of 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile. The method provided by the present invention can effectively remove aldehyde group-containing impurities in the intermediate. The method of the present invention has the advantages of simple operation, cheap raw materials and mild conditions, and is suitable for large-scale industrial production.Type: ApplicationFiled: December 28, 2021Publication date: March 21, 2024Applicants: ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD., Zhejiang Huahai LiCheng Pharmaceutical Co., Ltd.Inventors: Jian ZHANG, Jichao WANG, Xiangqian YOU, Liangwei QIAN, Tao ZHOU, Jiaxing HU, Wenfeng HUANG
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Patent number: 11919884Abstract: A method for preparing voriconazole L-camphorsulphonate and voriconazole. The method for preparing voriconazole L-camphorsulphonate comprises: method 1: dissolving (2R,3S)/(2S,3R) isomer mixture and L-camphor sulphonic acid in water and acetone, and performing crystallisation filtration to obtain voriconazole L-camphorsulphonate; method 2: (a) dissolving a mixture of isomer mixture and L-camphor sulphonic acid in a first solvent and then performing crystallisation filtration; or (a?) dissolving L-camphorsulphonate of the isomer mixture in a first solvent and then performing crystallisation filtration; (b) concentrating the filtrate obtained in step (a) or (a?) into a solid; and (c) dissolving the solid obtained in step (b) in a second solvent and performing crystallisation filtration to obtain voriconazole L-camphorsulphonate. Adjusting the resolution solvent effectively reduces production costs and facilitates recycling of the resolution solvent.Type: GrantFiled: November 10, 2016Date of Patent: March 5, 2024Assignee: Zhejiang Huahai Pharmaceutical Co., Ltd.Inventors: Hu Huang, Wenfeng Huang, Guoliang Tu, Zhongming Xu, Qianghui Wu, Zhaoyang Meng, Yuling Fang
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Publication number: 20220162189Abstract: Disclosed is a method for preparing voriconazole and an intermediate thereof In the method, a voriconazole condensate isomer is reacted as a starting material in the presence of an acid to obtain 4-chloro-6-ethyl-5-fluoropyrimidine and 2?,4?-difluoro-2-[1-(1H-1,2,4-triazolyl)]acetophenone. A method for preparing voriconazole by using the intermediate thus obtained is further disclosed. By adopting the method of the present invention, the utilization rate of starting materials and auxiliary materials for preparing voriconazole on the basis of the prior art can be greatly improved, thereby reducing costs.Type: ApplicationFiled: February 18, 2020Publication date: May 26, 2022Inventors: Wenxiang ZHOU, Wenfeng HUANG, Jiaxing HU
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Publication number: 20220113982Abstract: An electronic device (such as an access point) that selectively changes to an alternative or different partition is described. During operation, when the electronic device is in a first power state (such as a lower power state), an integrated circuit in the electronic device may detect or receive an error state or a change instruction. In response, the integrated circuit may change an active partition in the electronic device from a first partition to a second partition. Next, the integrated circuit may transition the electronic device to a second power state (such as a higher power state). Furthermore, a processor in the electronic device (which may be the same as or different from the integrated circuit) may install and execute an operating system of the electronic device in the second partition.Type: ApplicationFiled: October 1, 2021Publication date: April 14, 2022Applicant: ARRIS Enterprises LLCInventors: Wenfeng Huang, Roland Chew, Wen Huang, Wei Wu
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Publication number: 20210276980Abstract: A method for preparing voriconazole L-camphorsulphonate and voriconazole. The method for preparing voriconazole L-camphorsulphonate comprises: method 1: dissolving (2R,3S)/(2S,3R) isomer mixture and L-camphor sulphonic acid in water and acetone, and performing crystallisation filtration to obtain voriconazole L-camphorsulphonate; method 2: (a) dissolving a mixture of isomer mixture and L-camphor sulphonic acid in a first solvent and then performing crystallisation filtration; or (a?) dissolving L-camphorsulphonate of the isomer mixture in a first solvent and then performing crystallisation filtration; (b) concentrating the filtrate obtained in step (a) or (a?) into a solid; and (c) dissolving the solid obtained in step (b) in a second solvent and performing crystallisation filtration to obtain voriconazole L-camphorsulphonate. Adjusting the resolution solvent effectively reduces production costs and facilitates recycling of the resolution solvent.Type: ApplicationFiled: November 10, 2016Publication date: September 9, 2021Inventors: Hu Huang, Wenfeng Huang, Guoliang Tu, Zhongming Xu, Qianghui Wu, Zhaoyang Meng, Yuling Fang
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Patent number: 10961194Abstract: Provided is a method for purifying ropinirole hydrochloride (4-2-di-n-propylaminoethyl-1,3-dihydro-2H-indole-2-ketohydrochloride). The method comprises: adding ropinirole hydrochloride containing a monopropyl impurity A into water, adding organic solvent, stirring and dissolving at room temperature, adding alkali, stirring, standing, demixing, and removing an aqueous layer; optionally, drying the organic layer by using anhydrous magnesium sulfate, and filtering; and adding acyl chloride or acid anhydride into the organic layer, stirring, concentrating the organic layer to be dry, adding an organic solvent into the obtained oily matter, adding concentrated hydrochloric acid, and stirring, so as to obtain the ropinirole hydrochloride. By using the method, the impurity A in the ropinirole hydrochloride can be effectively removed, and the ropinirole hydrochloride can be obtained with a high yield and a high purity, so that the impurity A is controlled and the purity of the product reaches a medicinal standard.Type: GrantFiled: June 16, 2017Date of Patent: March 30, 2021Assignees: ZHEJIANG HUAHAI LICHENG PHARMACEUTICAL CO., LTD., ZHEJIANG HUAHAI PHARMACEUTICALS CO., LTD.Inventors: Guoliang Tu, Zhongming Xu, Tao Zhou, Wenfeng Huang, Shiwen Zhang
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Publication number: 20200172482Abstract: Provided is a method for purifying ropinirole hydrochloride (4-2-di-n-propylaminoethyl-1,3-dihydro-2H-indole-2-ketohydrochloride). The method comprises: adding ropinirole hydrochloride containing a monopropyl impurity A into water, adding organic solvent, stirring and dissolving at room temperature, adding alkali, stirring, standing, demixing, and removing an aqueous layer; optionally, drying the organic layer by using anhydrous magnesium sulfate, and filtering; and adding acyl chloride or acid anhydride into the organic layer, stirring, concentrating the organic layer to be dry, adding an organic solvent into the obtained oily matter, adding concentrated hydrochloric acid, and stirring, so as to obtain the ropinirole hydrochloride. By using the method, the impurity A in the ropinirole hydrochloride can be effectively removed, and the ropinirole hydrochloride can be obtained with a high yield and a high purity, so that the impurity A is controlled and the purity of the product reaches a medicinal standard.Type: ApplicationFiled: June 16, 2017Publication date: June 4, 2020Inventors: Guoliang TU, Zhongming XU, Tao ZHOU, Wenfeng HUANG, Shiwen ZHANG
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Patent number: 10633368Abstract: Provided is a synthesis method for a voriconazole intermediate condensate as shown in formula II or an acid addition salt thereof. As shown in reaction formula 1, the product is prepared via compounds III and IV. The synthesis method adjusts the feeding means, and the reaction conditions are mild and controllable, thereby reducing the production of impurity A, avoiding the use of highly toxic metal lead, and eliminating the risk of highly toxic metal remaining in a drug. The product has a higher purity and significant industrial application value.Type: GrantFiled: January 16, 2017Date of Patent: April 28, 2020Assignee: ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD.Inventors: Hu Huang, Wenfeng Huang, Guoliang Tu, Jiegen Liu, Zhongming Xu, Qianghui Wu, Zhaoyang Meng, Yuling Fang
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Patent number: 10508076Abstract: Provided is a method for resolution of formula 4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxy-methyl benzonitrile as an enantiomer thereof, comprising the following steps: a salt of (S)-4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxymethyl benzonitrile with a resolving agent D-(+)di-p-toluoyl tartaric acid was crystallized in a resolving solvent; the method is characterized in that the resolving solvent is an ether solvent. Also provided is a new crystal form of the resolved intermediate.Type: GrantFiled: February 22, 2019Date of Patent: December 17, 2019Assignee: Zhejiang huahai Pharmaceuticals Co., Ltd.Inventors: Zunjun Liang, Siqi Hu, Caihua Peng, Wenfeng Huang, Qifeng Lu, Guoliang Tu
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Publication number: 20190185418Abstract: Provided is a method for resolution of formula 4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxy-methyl benzonitrile as an enantiomer thereof, comprising the following steps: a salt of (S)-4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxymethyl benzonitrile with a resolving agent D-(+)di-p-toluoyl tartaric acid was crystallized in a resolving solvent; the method is characterized in that the resolving solvent is an ether solvent. Also provided is a new crystal form of the resolved intermediate.Type: ApplicationFiled: February 22, 2019Publication date: June 20, 2019Inventors: Zunjun LIANG, Siqi Hu, Caihua PENG, Wenfeng HUANG, Qifeng LU, Guoliang TU
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Patent number: 10287240Abstract: Provided is a method for resolution of formula 4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxy-methyl benzonitrile as an enantiomer thereof, comprising the following steps: a salt of (S)-4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxymethyl benzonitrile with a resolving agent D-(+)di-p-toluoyl tartaric acid was crystallized in a resolving solvent; the method is characterized in that the resolving solvent is an ether solvent. Also provided is a new crystal form of the resolved intermediate.Type: GrantFiled: November 14, 2014Date of Patent: May 14, 2019Assignee: Zhejiang Hushai Pharmaceuticals Co., Ltd.Inventors: Zunjun Liang, Siqi Hu, Caihua Peng, Wenfeng Huang, Qifeng Lu, Guoliang Tu
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Patent number: 10227293Abstract: The present invention relates to a method for preparing a citalopram diol represented by formula IV, comprising the following steps: in the existence of an auxiliary reagent of metal salt, allowing 5-cyanophthalide to sequentially subjected to Grignard addition reactions with p-fluorophenyl magnesium halide and N, N-dimethylaminopropyl magnesium halide in an organic solvent; and after the reactions are completed, performing hydrolysis and separation to obtain citalopram diol represented by formula IV. In the present invention, by adding an auxiliary reagent of metal salt, the activity and the selectivity of the Grignard reactions are remarkably improved, and the reaction yield is obviously enhanced.Type: GrantFiled: June 9, 2015Date of Patent: March 12, 2019Assignees: Zhejiang Huahai Pharmaceutical Co., Ltd, Zhejiang Huahai Licheng Pharmaceutical Co., Ltd, Zhejiang Huahai Jiancheng Pharmaceutical Co., LtdInventors: Zunjun Liang, Weifeng Xiao, Caihua Peng, Wenfeng Huang, Guoliang Tu
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Publication number: 20190002440Abstract: Provided is a synthesis method for a voriconazole intermediate condensate as shown in formula II or an acid addition salt thereof. As shown in reaction formula 1, the product is prepared via compounds III and IV. The synthesis method adjusts the feeding means, and the reaction conditions are mild and controllable, thereby reducing the production of impurity A, avoiding the use of highly toxic metal lead, and eliminating the risk of highly toxic metal remaining in a drug. The product has a higher purity and significant industrial application value.Type: ApplicationFiled: January 16, 2017Publication date: January 3, 2019Inventors: Hu Huang, Wenfeng Huang, Guoliang Tu, Jiegen Liu, Zhongming Xu, Qianghui Wu, Zhaoyang Meng, Yuling Fang
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Publication number: 20180162805Abstract: The present invention relates to a method for preparing a citalopram diol represented by formula IV, comprising the following steps: in the existence of an auxiliary reagent of metal salt, allowing 5-cyanophthalide to sequentially subjected to Grignard addition reactions with p-fluorophenyl magnesium halide and N, N-dimethylaminopropyl magnesium halide in an organic solvent; and after the reactions are completed, performing hydrolysis and separation to obtain citalopram diol represented by formula IV. In the present invention, by adding an auxiliary reagent of metal salt, the activity and the selectivity of the Grignard reactions are remarkably improved, and the reaction yield is obviously enhanced.Type: ApplicationFiled: June 9, 2015Publication date: June 14, 2018Inventors: Zunjun LIANG, Weifeng XIAO, Caihua PENG, Wenfeng HUANG, Guoliang TU
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Publication number: 20180155326Abstract: The present invention uses a candesartan cyclic compound as a starting material and performs thereon a three-step reaction of forming tetrazole, hydrolysis and adding a protecting group to directly obtain trityl candesartan without separating an intermediate product via crystallization. The operating process is simple and thus is more applicable to industrial production.Type: ApplicationFiled: June 5, 2015Publication date: June 7, 2018Applicant: ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD.Inventors: Enmin Lin, Mengjian Mou, Guoliang Tu, Wenfeng Huang
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Publication number: 20170240505Abstract: Provided is a method for resolution of formula 4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxy-methyl benzonitrile as an enantiomer thereof, comprising the following steps: a salt of (S)-4-[4-dimethylamino-1-(4-fluorophenyl)-1-hydroxylbutyl]-3-hydroxymethyl benzonitrile with a resolving agent D-(+)di-p-toluoyl tartaric acid was crystallized in a resolving solvent; the method is characterized in that the resolving solvent is an ether solvent. Also provided is a new crystal form of the resolved intermediate.Type: ApplicationFiled: November 14, 2014Publication date: August 24, 2017Inventors: Zunjun LIANG, Siqi HU, Caihua PENG, Wenfeng HUANG, Qifeng LU, Guoliang TU
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Patent number: 8213936Abstract: A method for providing a handoff in a network environment is provided that includes a mobile station operable to conduct a call. The mobile station is further operable to initiate a call leg autonomously such that a generic transfer function is invoked. The mobile station leverages the generic transfer function in order to execute a handoff for the mobile station.Type: GrantFiled: November 29, 2005Date of Patent: July 3, 2012Assignee: Cisco Technology, Inc.Inventors: Wenfeng Huang, Michael Chang-Ping Chen, Huizhao Wang, Xiaode Xu
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Patent number: 8005030Abstract: Methods, apparatuses and systems directed to facilitating WLAN diagnostics and management using traffic stream metrics. In a data collection stage, according to one implementation of the present invention, localized uplink measurements are taken at a wireless client associated with a wireless access point. During periodic intervals (e.g., every 5 seconds), the wireless client, in one implementation, transmits uplink measurement information to the wireless access point. The wireless access point may also take downlink measurements, which may also include one or more of the following metrics: observed latency, queuing delay, packet loss rate, and packet count information. The wireless access point, in one implementation, may aggregate and report the uplink and downlink metric information to a network management system.Type: GrantFiled: December 30, 2005Date of Patent: August 23, 2011Assignee: Cisco Technology, Inc.Inventors: David Sheldon Stephenson, Arnold Mark Bilstad, Wenfeng Huang, Jason Kim
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Patent number: 7680074Abstract: An apparatus and method for switching a mobile processing device from communicating over a wireless connection with a first base unit to a second base unit based upon latency. In accordance with this invention, the mobile processing device determines latency information for packets being transmitted over the wireless connection to and from a base unit. The latency information is compared to a threshold value. If the latency information is greater than the threshold value, the mobile processing device adjusts parameters of the wireless connection between the mobile processing device and the network.Type: GrantFiled: July 9, 2004Date of Patent: March 16, 2010Assignee: Cisco Technology, Inc.Inventors: Xiaode Xu, David Sheldon Stephenson, Wenfeng Huang, Huizhao Wang, Arnold Mark Bilstad
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Patent number: 7647046Abstract: A method, an apparatus, and code in a carrier medium to operate in a first access point of a wireless network in communication with at least one associated client station. The method includes wirelessly broadcasting a management frame including an indication that the first access point will stop being active, such that each associated client station can wirelessly roam to a second access point prior to the first access point ceasing being active. One embodiment further includes reducing the transmit power of wireless communication used to wirelessly transmit information to the associated client stations, such that each associated client station can eventually wirelessly roam to the second access point.Type: GrantFiled: January 12, 2005Date of Patent: January 12, 2010Assignee: Cisco Technology, Inc.Inventors: Wenfeng Huang, Huizhao Wang, Xiaode Xu, Arnold M. Bilstad