B01J31/122

Method for synthesizing pitavastatin t-butyl ester
11814355 · 2023-11-14 ·

A method for synthesizing pitavastatin tert-butyl ester includes obtaining a substance B through reacting (4R-CIS)-6-chloromethyl-2,2-dimethyl-1,3-dioxolane-4-acetic acid tert-butyl ester with a substance A under the action of a first base catalyst, 5 oxidizing with an oxidizing agent to obtain a substance C, then reacting with 2-cyclopropyl-4-(4-fluorophenyl)-quinoline-3-formaldehyde under the action of a second base catalyst to obtain a substance D, and finally, carrying out an acid deprotection to obtain pitavastatin t-butyl ester. The reaction conditions of the present invention are mild and controllable, and the reaction conditions of the synthesis of the Julia olefination do 10 not require an ultra-low temperature reaction. The operation is convenient and simple, the stereoselectivity is good, the yield is high, and the synthesized pitavastatin t-butyl ester is a completely non-cis isomer, and its purity is high.

System and method of producing carbon nanotubes
11820660 · 2023-11-21 · ·

A system and method of producing carbon nanotubes from flare gas and other gaseous carbon-containing sources.

Catalyst precursor

A method of forming dialkyl carbonate is provided, which includes introducing carbon dioxide into a catalyst to form dialkyl carbonate, wherein the catalyst is formed by activating a catalyst precursor using alcohol, wherein alcohol is R.sup.3—OH, and R.sup.3 is C.sub.1-12 alkyl group or C.sub.5-12 aryl or heteroaryl group. The catalyst precursor is formed by reacting Sn(R.sub.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4, and Sn(R.sup.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4 have a molar ratio of 1:2 to 2:1. R.sup.1 is C.sub.1-10 alkyl group, R.sup.2 is H or C.sub.1-12 alkyl group, and L is O—(C═O)—R.sup.5, and R.sup.5 is C.sub.1-12 alkyl group. The dialkyl carbonate is ##STR00001##

Processes for Producing Fluorided Solid Oxides and Uses Thereof in Metallocene-Based Catalyst Systems
20220331790 · 2022-10-20 ·

Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.

ANTIFOULING OLIGOMERIZATION CATALYST SYSTEMS

A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.

ANTIFOULING OLIGOMERIZATION CATALYST SYSTEMS

A catalyst system that may reduce polymeric fouling may include at least one titanate compound, at least one aluminum compound, and an antifouling agent. The antifouling agent may be chosen from one or more of a phosphonium or phosphonium salt; a sulfonate or a sulfonate salt; a sulfonium or sulfonium salt; an ester including a cyclic moiety; an anhydride; a polyether; and a long-chained amine-capped compound. The catalyst system may further include a non-polymeric ether compound.

Organotin catalysts in esterification processes of furan-2,5-dicarboxylic acid (FDCA)

Sugar-based mono and diesters are prepared by esterification of 2,5-furan-dicarboxylic acid (FDCA) with an alcohol in the presence of low loadings of a homogeneous organotin (IV) catalyst.

Processes for producing fluorided solid oxides and uses thereof in metallocene-based catalyst systems

Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.

Method and apparatus of preparing catalyst for fuel cell

A method for producing a catalyst for a fuel cell comprising: a) injecting carbon particles into a fluidized bed reactor; b) evacuating the fluidized bed reactor to form a base pressure; c) introducing a catalytic metal precursor together with a carrier gas into the fluidized bed reactor to contact the catalytic metal precursor with the carbon particles; d d) purging a purge gas into the fluidized bed reactor; e) introducing a reaction gas into the fluidized bed reactor to attach the catalytic metal precursor to the carbon particles; and f) purging a purge gas into the fluidized bed reactor, wherein, the catalytic metal is attached to the carbon particles in a form of nano-sized spot.

CATALYST PRECURSOR

A method of forming dialkyl carbonate is provided, which includes introducing carbon dioxide into a catalyst to form dialkyl carbonate, wherein the catalyst is formed by activating a catalyst precursor using alcohol, wherein alcohol is R.sup.3—OH, and R.sup.3 is C.sub.1-12 alkyl group or C.sub.5-12 aryl or heteroaryl group. The catalyst precursor is formed by reacting Sn(R.sub.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4, and Sn(R.sup.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4 have a molar ratio of 1:2 to 2:1. R.sup.1 is C.sub.1-10 alkyl group, R.sup.2 is H or C.sub.1-12 alkyl group, and L is O—(C═O)—R.sup.5, and R.sup.5 is C.sub.1-12 alkyl group. The dialkyl carbonate is

##STR00001##