Disclosed is a process for preparing a diaryl oxalate which comprises the step of transesterifying a dialkyl oxalate or/and an alkylaryl oxalate with an aryl alcohol in the presence of a tetra(aryloxy)titanium as a catalyst, wherein the tetra(aryloxy)titanium is fed into a reaction system of the transesterification as an aryl alcohol solution of the tetra(aryloxy)titanium which is prepared by reacting a tetraalkoxy titanium and an excess amount of the aryl alcohol and removing a by-producing alkyl alcohol.
METHOD FOR PRODUCING MONOMER FOR SINGLE-STRANDED NUCLEIC ACID MOLECULE
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:US20190100540A1
公开(公告)日:2019-04-04
A compound represented by formula (3):
or an enantiomer thereof can be obtained by comprising: reacting a compound represented by formula (1):
or an enantiomer thereof with 6-hydroxyhexanoic acid in a solvent in the presence of an additive such as 1-hydroxybenzotriazole and a condensing agent, and then mixing the resultant reaction mixture, water, and a base such as alkali metal hydroxide to produce a compound represented by formula (2):
or an enantiomer thereof; and reacting the compound represented by formula (2) or an enantiomer thereof with 2-cyanoethyl-N,N,N′,N′-tetraisopropylphosphorodiamidite in a solvent in the presence of a coupling activator.
Arylspiroborates Derived from 4-<i>tert</i>-Butylcatechol and 3,5-Di-<i>tert</i>-butylcatechol and Their Antimicrobial Activities
作者:Michael I. Webb、Nathan R. Halcovitch、Eric G. Bowes、Graham M. Lee、Michael J. Geier、Christopher M. Vogels、Taryn O'Neill、Haoxin Li、Andrew Flewelling、Andreas Decken、Christopher A. Gray、Stephen A. Westcott
DOI:10.1002/jhet.1997
日期:2014.1
A family of arylspiroborates has been prepared by the addition of either 4‐tert‐butylcatechol or 3,5‐di‐tert‐butylcatechol to boric acid and an alkali metal hydroxide. All compounds were characterized fully using multinuclear NMR spectroscopy and by elemental analyses. A single crystal X‐ray diffraction was carried out on potassium (bis‐(3,5‐di‐tertbutyl[1,2‐benzenediolato(2‐)‐O,O′]borate)) (8). All
Dual functional catalyst for selective opening of cyclic paraffins and process for using the catalyst
申请人:Galperin B. Leonid
公开号:US20050101819A1
公开(公告)日:2005-05-12
A catalyst for selectively opening cyclic paraffins has been developed. The catalyst comprises a Group VIII metal, such as platinum, a modifier component, such as niobium or ytterbium, a molecular sieve, such as UZM-16 and a refractory inorganic oxide such as alumina. The Group VIII metal and modifier component are preferably deposited on the refractory inorganic oxide. A process for using the catalyst is also disclosed.
An aluminosilicate zeolite and substituted versions designated UZM-15 have been synthesized. These zeolites are prepared using an organo-ammonium cation as a template in which at least one organic group has at least 2 carbon atoms. An example of such a cation is diethyldimethyl-ammonium cation. The template can optionally comprise other organoammonium cations, alkali metals and alkaline earth metals. These UZM-15 materials can be dealuminated by various processes to provide UZM-15HS compositions. Both the UZM-15 and UZM-15HS compositions are useful as catalysts or catalyst supports in various process such as the conversion of cyclic hydrocarbons to non-cyclic hydrocarbons and olefin oligomerization.