Ts. M. Frenkel

Reaction of cyanurates with the epoxide ring

ConclusionsIn the case of the reaction of triphenylcyanurate and phenyl glycidyl ether, we showed that the oxirane rings may react at high temperature with the cyanurate rings to form isocyanurate fragments, which, in turn, react with excess epoxide to form oxazolidone rings.

The preparation and X-ray structural study of complexes that catalyze isocyanate cyclotrimerization

A 1∶1-complex of trinitrophenol with benzyldimethylamine (1) and a 1∶1∶1-complex, the product of the interaction of benzyldimethylamine, glycidyl phenyl ether, and phenol (2), have been synthesized and characterized by means of X-ray analysis. Complex1 is a precursor for the catalysts of selective isocyanate cyclotrimerization, while complex2 is one of those catalysts. In the crystal structure complex1 forms H-bonded cationic-anionic aggregates with proton transfer from phenol to the N-atom of the tertiary amine. Complex2 crystallizes as a monohydrate (2a) with a strong H-bond between the quaternary ammonium and phenolic components, and exists in crystals in the form of globular H-bonded dimeric hydrates. Possible pathways of dissociation of complex2a are discussed. The data obtained may be used as a basis for further interpretation of the regularities of cyclotrimerization of isocyanates catalyzed by complexes of this type.

Thermodynamics of phenyl glycidyl ether and its reactions with diphenylcarbodiimide and phenyl isocyanate with the formation of iminooxazolidine and oxazolidinone in the 0–330 K range

Conclusions1.The temperature dependence of the heat capacity of phenyl glycidyl ether in vitreous, crystalline, supercooled liquid and liquid states was studied in an adiabatic vacuum calorimeter in the 14–330‡K range with an error of -0.3 %. The temperature, enthalpy and entropy of fusion, as well the glass transition temperature were determined.2.The thermodynamic functions H‡(T)-H‡(O), S‡(T), G‡(T)-H‡(O) were calculated for the range of 0–330 K; the zero entropy and the difference between the zero enthalpies of a vitreous and crystalline phenyl glycidyl ether were calculated; the thermodynamic parameters of its formation at a standard pressure and T=298.15 K were calculated.3.The enthalpy, entropy, and Gibbs energy of the reaction of phenyl glycidyl ether with diphenylcarbodiimide and phenylisocyanate were calculated. It was found that these processes are thermodynamically permissible over the whole temperature range studied and have an upper limiting temperature.

Thermodynamic properties of 3-phenyl-5-phenoxymethyl-2-oxazolidinone and 3-phenyl-5-phenoxymethyl-2-N-phenyliminooxazolidine between O and 330 K

Conclusions1.We have studied the temperature dependence of the heat capacity of 3-phenyl-5-phenoxymethyl-2-oxazolidinone and 3-phenyl-5-phenoxymethyl-2-N-phenyliiainooxazolidine between 14 and 330 K with an error of −0.3% in an adiabatic vacuum calorimeter. We have determined the enthalpy of combustion of these compounds at 298.15 K and 101.325 kPa in an isothermal bomb calorimeter.2.The data obtained have been used to calculate the following thermodynamic functions in the 0 to 330 K interval: H°(T)-H°(O), S°(T), G°(T)-H°(0). The following thermodynamic parameters of formation were calculated for 298.15 K and 101.325 kPa: ΔHf°, ΔSf°, and AGf°.

Reactions that occur during the synthesis of 3-phenyl-5-phenoxymethyl-2-N-phenyliminooxazolidine

Conclusions3-Phenyl-5-phenoxymethyl-2-N-phenyliminooxazolidine, formed by the reaction of diphenyl-carbodiimide with phenyl glycidyl ether, reacts with an excess of the latter to give 3-phenyl-5-phenoxymethyl-2-oxazolidone.

Mechanism of reaction of phenyl glycidyl ether with phenyl benzoate in the presence of water

The reaction of phenyl glycidyl ether with phenyl benzoate in the presence of water was investigated by adsorption liquid chromatography.

Synthesis and X-ray crystallographic investigation of 3-phenyl-3-phenoxymethyl-2-oxazolidinone

Conclusions3-Phenyl-5-phenoxymethyl-2-oxazolidinone is the product of interaction of phenylisocyanate with phenylglycidyl ether. Its molecule has a less strained conformation than the molecule of related 2-N-phenylimino-3-phenyl-5-phenoxymethyloxazolidine.

Structure and reactivity of heterosubstituted nitriles. 22. Study of the rate and the thermal effect of cyclotrimerization of substituted aryl cyanates

Conclusions1.The authors studied the kinetics and measured the thermal effect of cyclotrimerization of a series of substituted aryl cyanates.2.They estimated the stabilization energy of the s-triazine cycle in the substituted triphenyl cyanurates formed.

Nature of active center in cyclotrimerization of aryl cyanates in presence of chromium(III) acetylacetonate

The obtained results make it possible to assume that the autocatalytic character of the cyclotrimerization of aryl cyanates in the presence of (acac)3Cr is associated with the accumulation of the active form of the catalyst as the reaction progresses.

Side reactions in synthesis of phenyl cyanate by acylation of phenol with cyanogen halides

To synthesize highly reactive aryl cyanates it is expedient to use cyanogen chloride as the acylating agent and run the synthesis with an equimolar ratio of the starting components.