Method for Preparing 4-[9-(6-Aminopurine)]-2-(S)-Hydroxyl-Butyric Acid Methyl Ester
    23.
    发明申请
    Method for Preparing 4-[9-(6-Aminopurine)]-2-(S)-Hydroxyl-Butyric Acid Methyl Ester 有权
    4- [9-(6-氨基嘌呤)] - 2-(S) - 羟基 - 丁酸甲酯的制备方法

    公开(公告)号:US20110201810A1

    公开(公告)日:2011-08-18

    申请号:US12747312

    申请日:2008-11-06

    IPC分类号: C07D473/34

    CPC分类号: C07D473/34 Y02P20/55

    摘要: The present invention discloses a novel method for preparing and purifying 4-(6-Amino-purin-9-yl)-2(S)-hydroxy-butyric acid methyl ester. The preparation started from cheap and easily available L-malic acid, which was transformed to intermediate I after simultaneous protection of the groups of 1-carboxyl and 2-hydroxyl. The intermediate I was selectively reduced to intermediate alcohol II, whose hydroxyl group was further transformed to an easily leaving group to afford intermediate III. The intermediate III was nucleophilically substituted with adenine to afford intermediate IV. The intermediate IV was deprotected and methyl-esterified simultaneously in methanol in the presence of an acid or a base to afford crude 4-(6-Amino-purin-9-yl)-2(S)-hydroxy-butyric acid methyl ester, which was purified by recrystallization to afford the purified product. Comparing with the prior preparation methods, the present method has advantages in low cost, mild conditions, high retention of the chiral center during the reaction, high productivity, great improvement in the quality and yield of the product and great decrease in cost, and thus is suitable for the production on a large scale.

    摘要翻译: 本发明公开了一种制备和纯化4-(6-氨基嘌呤-9-基)-2(S) - 羟基 - 丁酸甲酯的新方法。 该制剂从便宜且易于获得的L-苹果酸开始,其在同时保护1-羧基和2-羟基的基团后转化为中间体I. 将中间体I选择性还原成中间体醇II,其中羟基进一步转化为容易离去的基团,得到中间体III。 中间体III用腺嘌呤亲核取代,得到中间体IV。 将中间体IV在酸或碱的存在下在甲醇中同时脱甲基酯化,得到粗制的4-(6-氨基 - 嘌呤-9-基)-2(S) - 羟基 - 丁酸甲酯, 通过重结晶纯化,得到纯化产物。 与现有的制备方法相比,本发明方法具有成本低,条件温和,反应中手性中心保留性高,生产效率高,产品质量和产量大幅提高,成本大幅降低的优点, 适合大规模生产。

    Water-Soluble Artemisinin Derivatives, Their Preparation Methods, the Pharmaceutical Compositions and the Use Thereof
    26.
    发明申请
    Water-Soluble Artemisinin Derivatives, Their Preparation Methods, the Pharmaceutical Compositions and the Use Thereof 有权
    水溶性青蒿素衍生物及其制备方法,药物组合物及其用途

    公开(公告)号:US20090298881A1

    公开(公告)日:2009-12-03

    申请号:US11989135

    申请日:2006-07-20

    CPC分类号: C07D493/18

    摘要: Water-soluble artemisinin derivatives, their preparation methods, the pharmaceutical compositions containing the same derivatives and the use thereof are disclosed. The artemisinin derivatives have following formula I. It has been proved by pharmacological tests that these compounds and compositions have evident immuno-suppressive activities, and may be used in the preparation of novel immuno-suppressants for treating the diseases caused by hyperfunction of human immunity (e.g. the auto-immune diseases such as lupus erythematosus, rheumatoid arthritis, multiple sclerosis and the like), and for inhibiting the graft rejection after cell or organ transplantation.

    摘要翻译: 公开了水溶性青蒿素衍生物及其制备方法,含有相同衍生物的药物组合物及其用途。 青蒿素衍生物具有以下式I:通过药理学实验证明,这些化合物和组合物具有明显的免疫抑制活性,可用于制备用于治疗由人免疫功能障碍引起的疾病的新型免疫抑制剂( 例如自身免疫疾病如红斑狼疮,类风湿性关节炎,多发性硬化症等),以及用于抑制细胞或器官移植后的移植排斥反应。

    METHODS FOR DESIGNING SECONDARY CUTTING STRUCTURES FOR A BOTTOM HOLE ASSEMBLY
    27.
    发明申请
    METHODS FOR DESIGNING SECONDARY CUTTING STRUCTURES FOR A BOTTOM HOLE ASSEMBLY 有权
    用于设计底部孔组件的二次切割结构的方法

    公开(公告)号:US20090055135A1

    公开(公告)日:2009-02-26

    申请号:US12179516

    申请日:2008-07-24

    IPC分类号: G06F17/50 G06G7/64

    摘要: A method for designing a secondary cutting structure for use in a bottom hole assembly, the method including defining initial design parameters for the secondary cutting structure and analyzing forces acting on the secondary cutting structure. Additionally, the method includes modifying at least one design element of the secondary cutting structure and simulating an effect of the modifying on both the secondary cutting structure and a primary cutting structure to determine if an improved condition is met. Also, a method for designing a drilling tool assembly, the method including defining initial drilling tool assembly design parameters including a primary cutting structure and a secondary cutting structure, and simulating a dynamic response of the drilling tool assembly. Additionally, the method includes adjusting at least one design element of the secondary cutting structure based on the dynamic response of the drilling tool assembly, determining if the adjusted design element improved a condition of the drilling, and repeating the simulating and adjusting until the condition is optimized.

    摘要翻译: 一种用于设计用于底部孔组件的二次切割结构的方法,所述方法包括限定次切割结构的初始设计参数和分析作用在次切割结构上的力。 此外,该方法包括修改次切割结构的至少一个设计元件并且模拟修正对次切割结构和主切割结构的影响,以确定是否满足改进的条件。 另外,一种用于设计钻具组件的方法,所述方法包括限定初始钻具组合设计参数,包括主切割结构和次切割结构,以及模拟钻具组件的动态响应。 此外,该方法包括基于钻具组件的动态响应来调整次切割结构的至少一个设计元件,确定调整后的设计元件是否改善了钻孔的状态,并重复模拟和调整,直到条件为 优化。

    Integrated circuit including a driver for a metal-semiconductor field-effect transistor
    28.
    发明授权
    Integrated circuit including a driver for a metal-semiconductor field-effect transistor 失效
    集成电路,包括用于金属半导体场效应晶体管的驱动器

    公开(公告)号:US06218891B1

    公开(公告)日:2001-04-17

    申请号:US09628266

    申请日:2000-07-28

    IPC分类号: H03K17687

    摘要: An integrated circuit including a metal-semiconductor field-effect transistor (MESFET) having a nominal intrinsic capacitance and requiring a negative voltage to bias the MESFET into a non-conduction state, a method of driving the MESFET and a power converter employing the integrated circuit and method. In one embodiment, the integrated circuit includes a driver including a bias capacitor integrated with the MESFET. The driver is configured to apply a positive voltage to bias the MESFET into a conduction state, and apply the negative voltage to bias the MESFET into the non-conduction state without employing an external negative bias source.

    摘要翻译: 一种集成电路,包括具有标称本征电容并需要负电压以将MESFET偏置为非导通状态的金属半导体场效应晶体管(MESFET),驱动MESFET的方法和采用该集成电路的功率转换器 和方法。 在一个实施例中,集成电路包括驱动器,其包括与MESFET集成的偏置电容器。 驱动器被配置为施加正电压以将MESFET偏置成导通状态,并且施加负电压以将MESFET偏置成非导通状态,而不使用外部负偏压源。

    Heavy weight drill pipe
    29.
    发明授权
    Heavy weight drill pipe 失效
    重型钻杆

    公开(公告)号:US6012744A

    公开(公告)日:2000-01-11

    申请号:US71253

    申请日:1998-05-01

    摘要: A heavy weight drill pipe member is disclosed for use in drilling high angle and horizontal well bores in a corrosive environment. The heavy weight drill pipe member consists of a tubular member with a longitudinal bore therethrough, and includes connectors or tool joints attached at each distal end for connecting additional heavy weight drill pipe members. The tubular member and tool joints are preheated, water quenched and tempered to obtain a unique combination of hardness, a yield strength and impact strength for improved resistance to stress corrosion cracking and hydrogen embrittlement in a hydrogen sulfide environment. The tubular member includes a plurality of wear pads or protectors equidistantly spaced along the longitudinal axis of the tubular member to reduce bending stress in the pipe by limiting the degree of bend when the pipe is placed in compression in a high angle well bore. To reduce the chances of differential pressure sticking of the pipe when the pipe is used in high angle or horizontal well bores, each wear pad or protector is provided with spiral grooves therein. Each wear pad or protector may also be hard faced or hard banded to reduce wear.

    摘要翻译: 公开了一种用于在腐蚀性环境中钻出大角度和水平井孔的重型钻杆构件。 重型钻杆构件由具有穿过其的纵向孔的管状构件组成,并且包括连接器或工具接头,其连接在每个远端,用于连接附加的重型钻杆构件。 管状构件和工具接头被预热,水淬火和回火,以获得硬度,屈服强度和冲击强度的独特组合,以改善耐硫化环境中的应力腐蚀开裂和氢脆化。 管状构件包括沿着管状构件的纵向轴线等距离间隔开的多个耐磨垫片或保护件,以通过限制管道在高角度井眼中压缩时的弯曲程度来减小管道中的弯曲应力。 为了减少当管道用于大角度或水平井眼时管子压差的可能性,每个磨损垫或保护器在其中设有螺旋槽。 每个磨损垫或保护膜也可能是硬面或硬带,以减少磨损。

    Pet water bowl
    30.
    外观设计

    公开(公告)号:USD910933S1

    公开(公告)日:2021-02-16

    申请号:US29684796

    申请日:2019-03-25

    申请人: Wei Tang

    设计人: Wei Tang