94563-11-8

Upstream product

• 67-56-1 methanol 
• 18523-41-6 4-azidobenzonitrile 
• 103-71-9 phenyl isocyanate 
• 79-22-1 methyl chloroformate 
• 873-74-5 4-Aminobenzonitrile 
• 616-38-6 carbonic acid dimethyl ester 
• 201230-82-2 carbon monoxide 
• 619-72-7 4-nitrobenzonitrile 
• 2597-44-6 formyl radical 
• 681-84-5 tetramethylorthosilicate 
• 124-38-9 carbon dioxide 

Downstream Products

• 1341755-28-9 methyl N-(4-carbamimidoylphenyl)carbamate 

Relevant academic research and scientific papers

A Simple Zinc Catalyst for Carbamate Synthesis Directly from CO2

Several zinc salts were employed as catalysts for the synthesis of carbamates directly from aromatic amines, CO2, and silicate esters. Zn(OAc)2 offered the best performance among the salts tested. The addition of an N-donor ligand such as 1,10-phenanthroline increased the yield. The best catalytic performance of Zn(OAc)2 can be explained by carboxylate-assisted proton activation. The interaction between the substrate and the catalyst can be observed by chemical shifts in 1H and 15N NMR spectra. Isocyanate was a key intermediate, which was generated from amine and CO2. Silicate ester was finally converted to siloxane, which was determined by 29Si NMR. The commercially available catalyst system could be reused. The yield of isolated carbamate could reach up to 96 % with various substrates, and the catalytic reaction was amine-selective in the presence of other functional groups.

Calcium carbide as a dehydrating agent for the synthesis of carbamates, glycerol carbonate, and cyclic carbonates from carbon dioxide

Carbon dioxide (CO2) is a nontoxic and inexpensive C1 building block, which can be used for the synthesis of valuable chemicals such as aromatic carbamates from anilines and methanol (MeOH), glycerol carbonate from glycerol, and cyclic carbonates from diols. However, these reactions generate water as the byproduct and suffer from thermodynamic limits, which lead to low yields. Calcium carbide (CaC2) is a renewable chemical, which can be recycled from calcium that is abundant in the Earth's crust. Furthermore, CaC2 rapidly reacts with water. In this work, we used CaC2 as a dehydrating agent for the direct synthesis of carbamates (including polyurethane precursors) from amines, CO2, and MeOH. All reagents were commercially available. In addition, CaC2 was employed for the synthesis of glycerol carbonate from glycerol and CO2 with a zinc catalyst and N-donor ligand. A similar protocol was applied to synthesize cyclic carbonates from diols and CO2.

PRODUCTION METHOD OF CARBAMIC ACID ESTER

A method of production of carbamic acid ester has a high yield and high selectivity and is superior in economy. The method of production of a carbamic acid ester includes reacting an amine, carbon dioxide, and an alkoxysilane compound in the presence of a catalyst containing a zinc compound or an alkali metal compound or in the presence of an ionic liquid. A carbamic acid ester is produced, for example by reacting aniline, carbon dioxide, and tetramethoxysilane at a temperature of 150 to 180° C. in the presence of zinc acetate and 2,2′-bipyridine.

Phosgene-free synthesis of carbamates using co2 and titanium alkoxides

A facile one-pot, phosgene-free method for the synthesis of N-phenylcarbamates is developed. Using this method, various aromatic carbamates could be prepared from aromatic amines, CO2 and metal alkoxides. Aniline reacted with titanium methoxide (Ti(OMe)4)) in the presence of CO2 (5 MPa) to give methyl N-phenylcarbamate in 85% yield, in 20min. Titanium residue could be regenerated by reaction with dimethyl carbonate at 220 °C for 16 h.

Direct synthesis of carbamate from CO2 using a task-specific ionic liquid catalyst

A superbase-derived protic ionic liquid (IL, [DBUH][OAc]) catalyst was used to directly synthesize carbamate from an amine, CO2, and a silicate ester. This IL catalyst was easily prepared using its precursors, DBU, and acetic acid. Using 10 mol% of the catalyst under a CO2 pressure of 5 MPa in acetonitrile at 150 °C, carbamate was isolated in up to 96% yield. Specifically, aliphatic and aromatic amines were activated even though aromatic amines exhibited low activities because of their low pKa values. Other functional groups in amines were barely activated, affording exclusive chemoselectivity for amine activation. Isotope labeling experiments indicated that the proton in the counter cation is crucial in the catalytic cycle to produce water. In addition, a chemical shift corresponding to a mixture of aniline and [DBUH][OAc] was observed in the 1H NMR spectrum, related to the formation of hydrogen bonds between aniline and basic acetate anions. The experimental results indicated that the designed IL catalysts require a protonated cation and a basic anion.

FACTOR XIa INHIBITORS

The present invention provides a compound of Formula (I); and pharmaceutical compositions comprising one or more said compounds, and methods for using said compounds for treating or preventing thromboses, embolisms, hypercoagulability or fibrotic changes. The compounds are selective Factor XIa inhibitors or dual inhibitors of Factor XIa and plasma kallikrein.

FACTOR XIa INHIBITORS

The present invention provides a compound of Formula (I) and pharmaceutical compositions comprising one or more said compounds, and methods for using said compounds for treating or preventing thromboses, embolisms, hypercoagulability or fibrotic changes. The compounds are selective Factor XIa inhibitors or dual inhibitors of Factor XIa and plasma kallikrein.

Copper-catalyzed mild nitration of protected anilines

A practical copper-catalyzed direct nitration of protected anilines, by using one equivalent of nitric acid as the nitrating agent, has been developed. This procedure features mild reaction conditions, wide structural scope (with regard to both N-protecting group and arene substitution), and high functional-group tolerance. Dinitration with two equivalents of nitric acid is also feasible. Practical and reliable: A Cu-catalyzed selective nitration of para- and ortho-substituted aniline derivatives by using one equivalent of HNO3 has been developed that produces water as the only stoichiometric byproduct (see scheme; PG=protecting group). This method is compatible with strongly electron-deficient substrates, enabling dinitration (by using 2.0 equiv of HNO3). This method allows for a rapid access to relevant nitrogen-containing heterocyclic architectures.

Efficient palladium/1,10-phenanthroline-catalyzed reductive carbonylation of mono- and dinitroarenes to urethanes in phosphonium salt ionic liquids

(Chemical Equation Presented) The highly reactive and selective reductive carbonylation of mono- and dinitroarenes to the corresponding mono- and diurethanes was carried out in the presence of a PdCl2/Phen catalytic system, using PSIL110[C14H29(C6H 13)3P+PF6-] as the ionic liquid under mild reaction conditions. No cocatalyst is required.

Indium-mediated efficient conversion of azides to carbamates

A novel and efficient method for the high yield preparation of carbamates by the reaction of azides with several chloroformates using indium metal in DMF at ambient temperature is described for the first time.