Effects of Concentrations in Isocyanat-Alcohol-Systems
The reaction between aromatic isocyanate and alcohol in nonpolar solvents at different alcohol and isocyanate concentrations and the effect of the presence of urethane in this solution at the start of the reaction have been examined.The results indicate that the rate constants of the observed second-order equation are dependent on the concentration of the reactants and of the urethane. Keywords.Association of alcohol and urethane; Spontaneous reaction; Urethane formation.
Triton-B catalyzed, efficient, one-pot synthesis of carbamate esters from alcoholic tosylates
A novel process for the one-step chemoselective conversion of a variety of alcoholic tosylates into carbamates serving as protected amines was developed using benzyltrimethylammonium hydroxide (Triton-B) in the presence of gaseous carbon dioxide. Thus car
Photo-on-Demand Synthesis of Chloroformates with a Chloroform Solution Containing an Alcohol and Its One-Pot Conversion to Carbonates and Carbamates
Chloroformates are key reagents for synthesizing carbonates and carbamates. The present study reports a novel photo-on-demand in situ synthesis of chloroformates with a CHCl3 solution containing a primary alkyl alcohol. It further allowed the one-pot synthesis of carbonates and carbamates through subsequent addition of alcohols or amines, respectively.
Synthesis of Amines, Carbamates and Amides by Multi-Step Continuous Flow Synthesis
We report the continuous flow synthesis of acyl azides in various continuous flow systems and demonstrate that liquid–liquid separation may be incorporated to prepare anhydrous solutions of the acyl azide, which may be subsequently reacted with appropriate nucleophiles to prepare amines, carbamates and amides within a fully integrated multi-step process in high yields (> 80 %). Interesting effects were also observed when preparing carbamates with long chain alcohols, whereby as the chain length of the alcohol increased the products could be made in high yield even without incorporation of the liquid–liquid separation module.
Sagandira, Cloudius R.,Watts, Paul
p. 6554 - 6565
(2017/10/09)
Efficient preparation of carbamates by Rh-catalysed oxidative carbonylation: unveiling the role of the oxidant
The synthesis of a wide variety of carbamates from amines, alcohols and carbon monoxide has been achieved by means of a Rh-catalysed oxidative carbonylation reaction that uses Oxone as a stoichiometric oxidant. In-depth studies on the reaction mechanism shed light on the intimate role of Oxone in the catalytic cycle.
Iturmendi, Amaia,Iglesias, Manuel,Munárriz, Julen,Polo, Victor,Pérez-Torrente, Jesús J.,Oro, Luis A.
p. 404 - 407
(2017/01/03)
(4-Arylsulfamoyl)phenylcarbamic acid esters: I. Synthesis and activity against herpes viruses
Aiming to modify the biological activity of sulfonamides, a number of alkyl (4-arylsulfamoyl)- phenylcarbamates were prepared in 50–70% yield. Biological screening showed that the target compounds possessed a high activity against herpes viruses as well as a traditional antibiotic one.
Krutikov,Erkin,Tets,Shmarov
p. 1567 - 1573
(2016/08/26)
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
Zhang, Xiaopeng,Jing, Huanzhi,Zhang, Guisheng
experimental part
p. 1614 - 1624
(2010/07/09)
Reactions of Aryl Isocyanates with Alcohols
The reaction of aryl isocyanates with alcohols has been kinetically studied as a model reaction for polyurethane formation under conditions similar to those of industrial scale production.Considering the isocyanate and alcohol structure, kinetic isotopic effect, activation enthalpy and entropy and solvent effects it has been found that the most probable mechanism is the alcohol addition through a four-membered cyclic transition state.
Bacaloglu, R.,Cotarca, L.,Marcu, N.,Toelgyi, St.
p. 428 - 434
(2007/10/02)
More Articles about upstream products of 7461-26-9