33013-98-8Relevant articles and documents
Determination of reaction parameters using a small calorimeter with an integrated FT-IR probe and parameter fitting
Pastre, Joerg,Zogg, Andreas,Fischer, Ulrich,Hungerbuehler, Konrad
, p. 158 - 166 (2001)
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.
Carbon dioxide utilization in the efficient synthesis of carbamates by deep eutectic solvents (DES) as green and attractive solvent/catalyst systems
Dindarloo Inaloo, Iman,Majnooni, Sahar
, p. 11275 - 11281 (2019/07/31)
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.
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
Sardarian, Ali Reza,Dindarloo Inaloo, Iman,Zangiabadi, Milad
, p. 8557 - 8565 (2019/06/14)
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.
