Novel synthesis of polyureas by ring-opening polyaddition-condensation reaction of 2-phenyl-1,3,4-oxadiazolin-5-one with diamines

A novel method for the synthesis of polyureas has been developed. This method involves ring-opening addition reaction of 2-phenyl-1,3,4-oxadiazolin-5-one with diamines, bis(4-aminophenyl) ether, 4,4′-methylenedianiline and m-xylylenediamine, followed by self-polycondensation of the resulting ring-opened adducts. Polymerizations in m-cresol at 150°C proceeded fast and were almost completed within 5 h. Polyureas were produced with reduced viscosities up to 0,38 dL · g⁻¹. A model compound study was performed to demonstrate the feasibility of the reaction for the formation of polyureas.     

Synthesis and reactions of 2-mercaptomethyl-1,3,4-oxadiazolin-5-one

Summary The title compound (4) was synthesized from thioglycolic acid hydrazide and ethyl chloroformate. The reactions of4 with aromatic amines, amino derivatives, hydrazine hydrate, hydroxylamine, and formamide were studied. Addition of compound4 to ,-unsaturated compounds,i.e. chalcones, maleic anhydride, quinones, and acrylonitrile, was investigated.

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Synthese und Reaktionen von 2-Mercaptomethyl-1,3,4-oxadiazolin-5-on

Zusammenfassung Die Titelverbindung (4) wurde aus Thioglycolsäurehydrazid und Chlorameisensäureethylester hergestellt. Die Reaktionen von4 mit aromatischen Aminen, Aminoderivaten, Hydrazinhydrat, Hydroxylamin und Formamid sowie die Addition von4 an ,-ungesättigte Verbindungen (Chalkone, Maleinsäureanhydrid, Chinone, Acetonitril) wurden untersucht.

     

Reaction of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine

Russian Chemical Bulletin - The formation of the n-σ* complex of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine of the composition C3H4N2S2·I2 in dilute chloroform solutions...     

Reaction of some benzoxazoline-2-thione derivatives with amines

Hydroxyphenylthioureas were obtained by the reaction of nitro, chloro, bromo, or amino derivatives of benzoxazoline-2-thiones with primary amines. If the substituent in the benzene ring is a nitro group, the reaction with certain secondary amines proceeds with the production of trisubstituted thioureas. It is shown that electron-acceptor substituents in the 5 and 6 positions of the benzene ring facilitate this reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 180–181, February, 1981.The authors thank P. Braikov, I. Nachev, I. Dukhova, and T. Georgiev for their assistance in carrying out some of the experiments.     

Direction of alkylation of 5-aryl-1,3,4-oxadiazoline-2-thiones

The reaction of potassium salt of 5-(2,4-dichlorophenyl)-1,3,4-oxadiazoline-2-thione with dimethyl sulfate was carried out in water and HMPT. It was shown that the nature of the solvent affects the ratio of the formed products of S- and N-methylation. The alkylation of 5-aryl-1,3,4-oxadiazoline-2-thiones with isomeric butyl chlorides showed that the reaction takes place only with n-butyl chloride with the formation of the corresponding S-butyl-substituted derivative.Institute of the Chemistry of Vegetable Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent 700170. Translated from Khimiya Geterotsikliheskikh Soedinenii, No. 9, pp. 1268–1270, September, 1997.     

Cyanoacetylenes in a reaction with benzoxazole-2-thione and benzoxazol-2-one

The reaction of benzoxazole-2-thione and benzoxazol-2-one with substituted cyanoacetylenes was studied. 2-[(3-Phenyl-2-propenenitrile)thio]benzoxazole was obtained by the reaction of benzoxazole-2-thione with phenylcyanoacetylene. Benzoxazol-2-one with phenylcyanoacetylene and a tertiary cyanoacetylenic alcohol gave the corresponding N-adducts.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1390–1391, June, 1990.     

Studies in the Vilsmeier-Haack reaction,part VII: Synthesis and reaction of 3-methyl-1-phenyl-4-acetyl hydrazono 2-pyrazoline-5-one(-5-thione)

Summary The keto (thio) tautomers1–4 of the hydrazono pyrazolone, thiopyrazolone derivatives underwent simultaneous diformylation, chlorination (desulphurization) and ring closure under Vilsmeier reaction conditions giving the pyrazolo[3,4-c]pyrazole aminoacroleins (5,6). Treatment of5 and/or6 with proper reagents afforded the corresponding pyrazolo[3,4-c]pyrazoles with different heterocyclic systems at the 3-position.The structures of these compounds were confirmed by elemental analysis, IR and¹H-NMR spectroscopy. All synthesized compounds have been screened in vitro for their antibacterial activities against a number of Gram-positive and Gram-negative bacteria.

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Untersuchungen zur Vilsmeier-Haack Reaktion, 7. Mitt.: Synthese und Reaktionen von 3-Methyl-1-phenyl-4-acetylhydrazono-2-pyrazolin-5-on(-5-thion)

Zusammenfassung Die Keto-(Thio)-Tautomeren1–4 der Hydrazonopyrazolon-/Thiopyrazolon-Derivate gingen unter Vilsmeier-Bedingungen zugleich Diformylierung, Chlorierung (Entschwefelung) und Ringschluß zu Pyrazolo[3,4-c]pyrazol-aminoacroleinen5 und6 ein. Aus5 und/oder6 konnten die entsprechenden Pyrazolo[3,4-c]pyrazole mit verschiedenen heterocyclischen Systemen in 3-Position erhalten werden. Die Strukturen der Verbindungen wurden mittels Elementaranalyse, IR und¹H-NMR überprüft. Alle synthetisierten Verbindungen wurden in vitro bezüglich ihrer antibakteriellen Aktivität gegenüber einer Anzahl Gram-positiver und Gram-negativer Bakterien untersucht.

     

4-benzoyl-5-phenyl-1,3-oxathiol-2-one. Synthesis and reaction with N-nucleophiles

The synthesis of 4-benzoyl-5-phenyl-1,3-oxathiol-2-ones 1 and the behaviour of 1a against several amines were investigated to afford aminomercaptoethenes 2 or thiocarbamates 3 , as well as complete cleavage to sulfur, dibenzoylmethane and the corresponding urea, depending on the nature of the N-nucleophile used.     

One-Pot Synthesis of 1,3,4-Thiadiazin-5-yl-chromen-2-one Derivatives via Three-Component Reaction

An expeditious, one-pot reaction has been described for the preparation of 1,3,4-thiadiazin-5-yl-chromen-2-one derivatives. These compounds were synthesized by the reaction of 3-(2-bromoacetyl)coumarin with thiocarbohydrazide and various carbonyl compounds. The newly synthesized compounds were characterized by infrared, ¹H NMR, and mass spectra.     

Reaction of 4-arylidene-3-methyl-1-phenyl-5-pyrazolones with amines

The reaction of primary and secondary amines with 4-arylidenepyrazolones gives the corresponding ammonium salts of 4,4-benzylidenebis-5-pyrazolone derivatives but not adducts on the exocyclic C=C bond as was previously believed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 905–908, July, 1988.     

5-Aryl-1,3,4-oxadiazoline-2(3H)-thiones in reactions with alkyl haloacetates

The reaction of 5-aryl-1,3,4-oxadiazoline-2(3H)-thiones with alkyl haloacetates has been studied. It was shown that the reaction proceeds to give S-substituted products. The effect of the nature of the substituents in the molecules of both the thiones and the haloacetates on the reaction route and yields has been examined.     

Basicity of 2-phenyl-5-R-1,3,4-oxadiazoles

We have studied the basicity of 2-phenyl-5-R-1,3,4-oxadiazoles (R = H, Me, CH₂Ph, t-Bu, CH₂Cl, CCl₃, CF₃) in aqueous sulfuric acid solutions. These compounds are weak organic bases (pK_BH ⁺ is −1.8 to −5.2). The values of pK_BH ⁺ determined on the H₀ and X acidity function scales agree well with each other. The substituent at the 5 position has a substantial effect on the basicity of the 1,3,4-oxadiazole ring. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 748–756, May, 2006.     

2-芳氧基-5-苯基-1,3,4-恶二唑类化合物的合成

通过芳氧基负离子在2-甲磺酰基-5-1,3,4-恶二唑上的亲核取代反应制得2-芳氧基-5-苯基-1,3,4-恶二唑.所有化合物的结构经元素分析,IR, ^1H NMR和MS确证.这些化合物表现出一定的抑制枯草芽孢杆菌繁殖的活性.     

Recyclization of 4,5-diphenyloxazolin-2-one and -2-thione under the influence of amines

4,5-Diphenyl-4-oxazolin-2-one and -2-thione undergo recyclization to 1-substituted 4,5-diphenyl-4-imidazolin-2-ones and -2-thiones, respectively, under the influence of primary amines. The action of hydrazine hydrate on the oxazolone leads to 5,6-diphenyl-1,2,3,4-tetrahydro-1,2,4-triazin-3-one. The corresponding ureas were isolated from the reaction mixtures in a number of cases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1028–1030, August, 1981.