33013-98-8

Upstream product

• 4221-99-2 (S)-2-butanol 
• 103-71-9 phenyl isocyanate 
• 17462-58-7 isobutyl chloroformate 
• 62-53-3 aniline 
• 201230-82-2 carbon monoxide 
• 78-92-2 iso-butanol 
• 2291-84-1 Tributylzinn-sek.-butylat 
• 75-65-0 tert-butyl alcohol 
• 591-50-4 iodobenzene 
• 2114-15-0 isobutyl carbamate 
• 108-86-1 bromobenzene 
• 590-28-3 potassium cyanate 
• 1919-48-8 2,4,6-triphenoxy-1,3,5-triazine 
• 78-86-4 s-butyl chloride 

Relevant academic research and scientific papers

Determination of reaction parameters using a small calorimeter with an integrated FT-IR probe and parameter fitting

To identify optimal operating conditions of a chemical process, knowledge on kinetic and thermodynamic parameters of the main reactions is needed. In particular in the fine chemical industry during the early phases of process development this knowledge is usually low. One reason is that only small amounts of substrate are available to perform the required calorimetric and analytical experiments. Therefore, we present in this paper a new prototype reaction calorimeter with a volume of 50 mL. Despite its small volume, the reaction calorimeter is combined with an IR-ATR probe to obtain augmented information from semibatch experiments under isothermal conditions. Furthermore, we present a new method to analyze the calorimetric measurements. The novelty of the approach is that all heat flows in the calorimeter are modeled together with the chemical reaction. For general reaction kinetics this reactor model cannot be solved analytically, and thus, numerical methods are applied for fitting the model parameters to the measurement data. In contrast to the traditional method of thermal conversion the rate constants and the heats of reaction are computed at the same time. The new reaction calorimeter and the new evaluation principle of the thermal signal were both tested using a single-step second-order model reaction. Also the FT-IR data were evaluated by fitting the parameters in the reactor model numerically. The reaction parameters obtained with both measurement techniques are in good agreement with values published in the literature demonstrating the feasibility of the approach.

Nickel-Catalyzed Synthesis of N-(Hetero)aryl Carbamates from Cyanate Salts and Phenols Activated with Cyanuric Chloride

A simple and efficient domino reaction has been designed and employed for the one-pot synthesis of N-(hetero)aryl carbamates through the reaction between alcohols and in-situ produced (hetero)aryl isocyanates in the presence of a nickel catalyst. The phenolic C?O bond was activated via the reaction of phenol with cyanuric chloride (2,4,6-trichloro-1,3,5-triazine (TCT)) as an inexpensive and readily available reagent. This strategy provides practical access to N-(hetero)aryl carbamates in good yields with high functional groups compatibility.

An Fe3O4@SiO2/Schiff base/Cu(ii) complex as an efficient recyclable magnetic nanocatalyst for selective mono: N-arylation of primary O-alkyl thiocarbamates and primary O-alkyl carbamates with aryl halides and arylboronic acids

An efficient, convenient and novel method for the selective mono N-arylation of primary O-alkyl thiocarbamates and primary O-alkyl carbamates with aryl halides and arylboronic acids in the presence of a recyclable magnetic Cu(ii) nanocatalyst is described. A variety of mono N-arylated O-alkyl thiocarbamates and O-alkyl carbamates were prepared in good to excellent yields with a broad range of aryl coupling partners. The magnetic nanocatalyst can be easily recovered with an external magnetic field and reused at least five times without noticeable leaching or loss of its catalytic activity. This cost-effective and eco-friendly methodology has some other advantages, such as easy preparation of the catalyst, simple workup procedure, and easy purification, which makes this protocol interesting for the users in various fields of pharmacology and biotechnology systems.

A Fe3O4?SiO2/Schiff Base/Pd Complex as an Efficient Heterogeneous and Recyclable Nanocatalyst for One-Pot Domino Synthesis of Carbamates and Unsymmetrical Ureas

A palladium-catalyzed domino method for the direct synthesis of carbamates and ureas has been developed by using readily available and economical starting materials (aryl halide, carbon monoxide, sodium azide, amines and alcohols) in a one-pot approach. The domino process underwent carbonylation, Curtius rearrangement, and nucleophilic addition. This protocol provides a step-economical and highly efficient reaction to access the wide range of valuable carbamates, symmetrical and unsymmetrical ureas with high yields under remarkable mild reaction conditions that are important factors in pharmaceutical science, biochemistry and agricultural industries. Furthermore, the magnetically recoverable nanocatalyst (Fe3O4?SiO2/Pd(II)) can be conveniently and swiftly recycled using external magnet and reused at least for seven times without noticeable loss of its catalytic activity.

Carbon dioxide utilization in the efficient synthesis of carbamates by deep eutectic solvents (DES) as green and attractive solvent/catalyst systems

A green and eco-friendly solvent/catalyst system based on a deep eutectic solvent (DES) was devised and developed for the simple synthesis of carbamates through three-component coupling of amines, alkyl halides and carbon dioxide (CO2). It was found that choline chloride:zinc(ii) chloride ([ChCl][ZnCl2]2) was very proficient and effective for the activation and utilization of CO2 in carbamate formation reactions from a wide scope of amines. Surprisingly, this strategy provides the desired carbamates under atmospheric CO2 pressure at room temperature. In particular, both aromatic and aliphatic amines were effective and demonstrated excellent yields. Besides, the [ChCl][ZnCl2]2 exhibited very high stability and also could be reused for at least five consecutive cycles without any significant loss of activity. It is worth noting that this is the first solvent/catalyst system which can be recycled successfully from the reaction mixture.

Selective Synthesis of Secondary Arylcarbamates via Efficient and Cost Effective Copper-Catalyzed Mono Arylation of Primary Carbamates with Aryl Halides and Arylboronic Acids

Abstract: An efficient, selective and cost-effective procedure has been developed for mono N-arylation of primary alkyl and benzyl carbamates with aryl iodides and bromides by incorporating CuI as an inexpensive and commercially available catalyst. Despite previous reports on C–N coupling reactions, this process does not need expensive ligands and takes advantage of readily available and inexpensive ethylenediamine (EDA) as the ligand. Reaction times were relatively short and related N-arylated carbamates were obtained in excellent yields. Interestingly, replacing CuI with Cu(OAc)2 allowed us to use arylboronic acids as coupling partner for this reaction. All products are well characterized by 1H- and 13C-NMR, MS, melting point, IR and CHNS techniques.

Ureas as safe carbonyl sources for the synthesis of carbamates with deep eutectic solvents (DESs) as efficient and recyclable solvent/catalyst systems

A simple, efficient and eco-friendly one-pot synthesis of primary, N-mono- and N-disubstituted carbamates is developed from ureas. The corresponding carbamates were produced at 120 °C, within 18 h, and in the presence of a deep eutectic solvent as a recyclable catalytic system. The catalyst can be reused for several runs without any reduction in its activity. To demonstrate the utility of this approach, a wide variety of alcohols and phenols were studied to find a vast range of carbamate derivatives in moderate to high yields.

Fe3O4@SiO2/Schiff base/Pd complex as an efficient heterogeneous and recyclable nanocatalyst for chemoselective: N -arylation of O -alkyl primary carbamates

An efficient, heterogeneous and cost effective method has been developed using an Fe3O4@SiO2/Schiff base/Pd complex as a magnetic and easily recyclable nanocatalyst for rapid and effective N-arylation of carbamates in good to excellent yield. The catalyst can be easily recovered and reused over six runs without significant decrease in the activity. Further highlights of this protocol are operational simplicity, versatility and relatively short reaction times.

Interaction between trialkyltin alkoxide and phenyl isocyanate in the formation of tin carbamate: A computational and experimental study

Organotin catalysts are used to catalyze the reaction of isocyanates and alcohols in the manufacture of urethanes. Therefore it is important to understand the mechanism of the catalysis to get a greater control of the reaction to obtain specific properties of the final product. Until now the proposed mechanism related to organotin catalysis of urethane formation is based on the mechanism suggested by Bloodworth and Davies (1965) on the reaction between trialkyltin alkoxide and phenyl isocyanate. In the present work computational and experimental methods were used to investigate the interaction between trialkyltin alkoxide and phenyl isocyanate. The computational results agree with the experimental results reported by Bloodworth and Davies. The computational investigation also provided further insight into the interaction mechanism. The investigations indicate that initially the isocyanate oxygen is attracted towards the tin atom of the organotin alkoxide, which subsequently undergoes an insertion reaction to form an organotin O-carbamate (methyl tributylstannyl phenylcarbonimidate), which rearranges to form an organotin N-carbamate (methyl phenyl(tributylstannyl)carbamate). Model compound studies of the urethane formation in the presence of trialkyltin catalyst using 13C NMR and FT-IR data show that the reaction goes through a termolecular mechanism. This is also confirmed by comparing reaction rates between trialkyl and dialkyl tin as catalyst at similar tin content for the reaction between aromatic isocyanate and alcohol and comparing with computationally calculated intrinsic reaction coordinate profile of different transition states for similar interactions.

Selenium-catalyzed oxidative carbonylation of aniline and alcohols to n-phenylcarbamates

A facile one-pot, phosgene-free synthesis of N-phenylcarbamates is demonstrated. Catalyzed by selenium, oxidative carbonylation of aniline with alcohols in the presence of carbon monoxide and oxygen affords the corresponding N-phenylcarbamates, mostly in fair to good yields. Selenium can be easily recovered because of its phase-transfer catalysis function. Copyright