46results about How to "Rate of reaction" patented technology

An efficient synthetic route to antiviral 2′,3′-dideoxy-2′,3′-didehydro-nucleosides, such as 2′,3′-dideoxy and 2′- or 3′-deoxyribo-nucleoside analogs, from available precursors is disclosed, with the option of introducing functionality as needed. In one embodiment, a method for the preparation of β-D and β-L-2′,3′-dideoxy-2′,3′-didehydro-nucleosides is described that includes: activating a compound of structure (1)

wherein B is a pyrimidine or purine base and Y is O, S or CH₂ with an acyl halide of the formula X—C(═O)R¹, X—C(═O)C(R¹)₂OC(═O)R¹ or X—C(═O)OR¹ (wherein X is a halogen, and each R¹ is independently hydrogen, lower alkyl, alkyl, aryl or phenyl); reducing the resulting compound with a reducing agent to form a 2′,3′-dideoxy-2′,3′-didehydro-nucleoside; and optionally deprotecting the nucleoside. The haloacylation of the first step can form the 2′-acyl-3′-halonucleoside, the 3′-acyl-2′-halonucleoside, or a mixture thereof.

Compositions, methods, substrates and systems for use in analysis of single molecule reactions and particularly single molecule nucleic acid sequence analysis. Compositions that include non-reactive, distinguishable or undetectable competitive substrates for the reaction system of interest are provided, as well as their use in systems and substrates for such applications, such compounds typically preferably polyphosphate chains or analogous structures.

A method of fracking carbonate-rich reservoirs, comprising injecting a cryogenic or chilled fluid followed by an acid into said reservoir, allowing the acid to etch said reservoir, and thereby increasing production of a fluid, such as water, oil or gas, from said reservoir.

The present invention relates to an organotin compound represented by R₁O—Sn—OR₂ (where R₁ and R₂ are independently a primary, secondary, or tertiary alkyl group having 5 to 30 carbon atoms), a preparation method thereof, and a preparation method for polylactide using the organotin compound. The organotin compound of the present invention is easy to prepare and is used to prepare a polylactide resin having a high molecular weight at a high yield without using a separate initiator.

Polynucleotides having allosteric properties that modify a function or configuration of the polynucleotide with a chemical effector and/or physical signal are employed primarily as biosensors and/or enzymes for diagnostic and catalytic purposes. In some preferred embodiments, the polynucleotides are DNA enzymes that are used in solution/suspension or attached to a solid support as biosensors to detect the presence or absence of a compound, its concentration, or physical change in a sample by observation of self-catalysis. Chemical effectors include organic compounds such as amino acids, amino acid derivatives, peptides, nucleosides, nucleotides, steroids, and mixtures of these with each other and with metal ions, cellular metabolites or blood components obtained from biological samples, steroids, pharmaceuticals, pesticides, herbicides, food toxins, and the like. Physical signals include radiation, temperature changes, and combinations thereof.

Provided are processes for preparing ziprasidone from CEI and BIPT.

A method of forming a hydrocarbon product and hydrogen gas comprises introducing CH₄ to a positive electrode of an electrochemical cell comprising the positive electrode, a negative electrode, and a proton-conducting membrane between the positive electrode and the negative electrode. The proton-conducting membrane comprises an electrolyte material having an ionic conductivity greater than or equal to about 10⁻² S/cm at one or more temperatures within a range of from about 150° C. to about 600° C. A potential difference is applied between the positive electrode and the negative electrode of the electrochemical cell to produce the hydrocarbon product and the hydrogen gas. A CH₄ activation system and an electrochemical cell are also described.

A thermal barrier coating and a cold-wall reactor including the coating are provided. A second ceramic layer is sandwiched between the conventional two-layer structures of the thermal barrier coating. The second ceramic layer is made of aluminum oxide stabilized zirconium oxide and the content of aluminum oxide does not exceed 30 wt %. The zirconium oxide in the first and second ceramic layer has a tetragonal crystal structure. A cold-wall reactor formed by applying the thermal barrier coating provides advantageous steel hydrogen corrosion resistance in ultra-high temperature. The effective volume of the hydrogenation reactor is fully used, overcoming the problem that the thermal insulation liner is easily damaged and causes local overheating of the reactor wall, as well as eliminating potential safety hazards of reactor wall local stress concentration caused by expansion and contraction of the liner cylinder attachment member.

In the process for producing a cyclododecanone by isomerizing an epoxycyclododecane-containing starting material in the presence of an isomerization reaction catalyst containing lithium bromide and/or lithium iodide, in order to perform the reaction with high efficiency (high reaction rate) and high selectivity and stably produce a high-purity cyclododecanone in industry while maintaining a high-level reaction rate, the epoxycyclododecane-containing starting material is produced by contacting an epoxycyclododecadiene with hydrogen in the presence of a hydrogen-reduction catalyst and has a content of the hydroxyl group-containing cyclododecane compounds contained in the epoxycyclododecane-containing starting material controlled to 5 mol % or less.

Disclosed is a method of determining the presence of an analyte of interest by means of a detection of a reaction product between the analyte of interest and a reactant, the method comprising extracting the analyte of interest from a complex sample matrix; transferring the analyte of interest to an initial reaction mixture; performing a background measurement on the initial reaction mixture comprising at most a negligible concentration of the reaction product, wherein the reaction conditions present in said initial reaction mixture at least reduce the reaction rate of the formation of the reaction product such that the background measurement can be performed without a measurable change in said negligible concentration; altering the reaction conditions in the initial reaction mixture to accelerate said reaction rate; continuing said reaction until the concentration of the reaction product has stabilized; performing a second measurement on the resultant reaction mixture to obtain a signal correlated to said concentration; and determining the presence of the analyte of interest from a difference between the background measurement and the second measurement. In a preferred embodiment, the analyte of interest is Propofol (2,6-di-isopropylphenol), and the reactant is the activated Gibbs reagent (2,6-dichloroquinoneimine).

A method of a hydrocarbon product and ammonia comprises introducing C₂H₆ to a positive electrode of an electrochemical cell comprising the positive electrode, a negative electrode, and a proton-conducting membrane between the positive electrode and the negative electrode. The proton-conducting membrane comprising an electrolyte material having an ionic conductivity greater than or equal to about 10⁻² S/cm at one or more temperatures within a range of from about 150° C. to about 600° C. N₂ is introduced to the negative electrode of the electrochemical cell. A potential difference is applied between the positive electrode and the negative electrode of the electrochemical cell. A system for co-producing higher hydrocarbons and NH₃, and an electrochemical cell are also described.