3898-08-6Relevant articles and documents
Green and efficient synthesis of thioureas, ureas, primary: O -thiocarbamates, and carbamates in deep eutectic solvent/catalyst systems using thiourea and urea
Bagherzadeh, Nastaran,Sardarian, Ali Reza,Inaloo, Iman Dindarloo
supporting information, p. 11852 - 11858 (2021/07/12)
An efficient and general catalysis process was developed for the direct preparation of various primary O-thiocarbamates/carbamates as well as monosubstituted thioureas/ureas by using thiourea/urea as biocompatible thiocarbonyl (carbonyl) sources. This procedure used choline chloride/tin(ii) chloride [ChCl][SnCl2]2 with a dual role as a green catalyst and reaction medium to afford the desired products in moderate to excellent yields. Moreover, the DES can be easily recovered and reused for seven cycles with no significant loss in its activity. Besides, the method shows very good performance for synthesizing the desired products on a large scale.
Exploration of SAR features by modifications of thiazoleacetic acids as CRTH2 antagonists
Grimstrup, Marie,Receveur, Jean-Marie,Rist, ?ystein,Frimurer, Thomas M.,Nielsen, Peter Aadal,Mathiesen, Jesper M.,H?gberg, Thomas
scheme or table, p. 1638 - 1641 (2010/07/15)
The SAR features have been further explored for (2-benzhydryl-4-phenyl-thiazol-5-yl)acetic acids as CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells) antagonists. The introduction of a nitrogen or a methyl substituent in the benzhydrylic position offer two alternative drugable scaffolds attractive for unsymmetrically substituted derivatives. An imidazole analogue lacks activity due to formation of a favored coplanar intramolecular hydrogen bond. The pyrimidine derivative 18 represents a potent and selective compound that will be subject to continued investigations.
Synthesis and characterization of some heterocyclic analogues of N,N′-perarylated phenylene-1,4-diamines and benzidines as a new class of hole transport materials
Schumann, Joerg,Kanitz, Andreas,Hartmann, Horst
, p. 1268 - 1276 (2007/10/03)
Starting from N,N-diarylsubstituted thioureas 20 and thioacetamides 21 a series of heterocyclic analogous of N,N′-perarylated phenylene-1,4-diamines and benzidines was obtained. These compounds represent, as studied by DSC measurements, a new class of hole transporting materials with high thermal stability and high tendency to form stable amorphous states. Moreover, some of the new compounds are, as measured by cyclic voltammetry, easily reversibly oxidized indicating the formation of persistent radical ions. Such compounds, which are, in general, completely substituted by aryl groups at their heterocyclic moieties, have been successfully used as hole-transport materials in OLEDs.
Experimental and theoretical studies on the thermal decomposition of heterocyclic nitrosimines
Bartsch,Yeh Moon Chae,Ham,Birney
, p. 7479 - 7486 (2007/10/03)
A series of substituted 2-nitrosiminobenzothiazolines (2) were synthesized by the nitrosation of the corresponding 2-iminobenzothiazolines (6). Thermal decomposition of 2a-f and of the seleno analogue 7 in methanol and of 3-methyl-2-nitrosobenzothiazoline (2a) in acetonitrile, 1,4-dioxane, and cyclohexane followed first-order kinetics. The activation parameters for thermal deazetization of 2a were measured in cyclohexane (ΔH? = 25.3 ± 0.5 kcal/mol, ΔS? = 1.3 ± 1.5 eu) and in methanol (ΔH? = 22.5 ± 0.7 kcal/mol, ΔS? = -12.9 ± 2.1 eu). These results indicate a unimolecular decomposition and are consistent with a proposed stepwise mechanism involving cyclization of the nitrosimine followed by loss of N2. The ground-state conformations of the parent nitrosiminothiazoline (9a) and transition states for rotation around the exocyclic C=N bond, electrocyclic ring closure, and loss of N2 were calculated using ab initio molecular orbital theory at the MP2/6-31G* level. The calculated gas-phase barrier height for the loss of N2 from 9a (25.2 kcal/mol, MP4(SDQ, FC)/6-31G*//MP2/6-31G* + ZPE) compares favorably with the experimental barrier for 2a of 25.3 kcal/mol in cyclohexane. The potential energy surface is unusual; the rotational transition state 9a-rot-ts connects directly to the orthogonal transition state for ring-closure 9aTS. The decoupling of rotational and pseudopericyclic bond-forming transition states is contrasted with the single pericyclic transition state (15TS) for the electrocyclic ring-opening of oxetene (15) to acrolein (16). For comparison, the calculated homolytic strength of the N-NO bond is 40.0 kcal/mol (MP4(SDQ, FC)/6-31G* + ZPE).
