3,4-Dihydro-benz[1,3]oxazine Derivatives from 2-Acyl(or aroyl)-cyanatobenzenes

3,4-Dihydro-2H-benz[1,3]oxazin-2-ones 3 are obtained from 2-acyl(or aroyl)-cyanatobenzenes 2 and anisole. The reaction proceeds under Friedel-Crafts conditions via DIMROTH rearrangement. Compounds 2 , dissolved in diethyl ether, react with 1 in the presence of finely powdered KOH at ambient temperature leading to 8 . The structure of 8b is confirmed by X-ray structure analysis. (Z)-4-Ethylidene - 3,4 - dihydro -2H-benz[1,3] oxazin-2-one 9 is formed upon treatment of 2-cyanatopropiophenone 2b with diluted hydrochloric acid. The ethylene derivative 5 is obtained from 4 upon reaction with cyanogen bromide/triethyl amine.     

An efficient synthesis of [1,3,4]thiadiazolo[2,3-c][1,2,4] triazin-4-ones

A three-component reaction between 4-amino-6-methyl-3-thioxo-3,4-dihydro-2H-[1,2,4]triazin-5-one, ammonium thiocyanate and aroyl chlorides in the presence of N-methylimidazole to afford the [1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-4-ones in excellent yields is described.     

Umsetzung von 1-(2-Benzoxazolon-3-yl)-2-propanonen mit Hydrazinhydrat

Reaction of 1-(2-Benzoxazolon-3-yl)-2-propanones with Hydrazinhydrate . The reaction of 1-(2-benzoxazolon-3-yl)-2-propanones 1a–g with hydrazinhydrate is studied. It is shown that according to the reactional conditions are obtained hydrazones 2a–b , azines 4a–b and 6-Methyl-4-(2-hydroxyphenyl)-2,3,4,5-tetrahydro-1,2,4-triazine-3-ones 6a–g . The structure of the products is discussed on the base of i.r. and n.m.r.-spectras.     

Pyryliumverbindungen. 45 [1]. 4-Aroyl-fluorene aus 2,4,6-Triaryl-pyryliumsalzen und Indan-1-on via 2-(5-Oxo-pent-2-en-1-yliden)-indan-1-one

Pyrylium Compounds. 45. 4-Aroyl-fluorenes from 2,4,6-Triaryl-pyrylium Salts and Indan-1-one via 2-(5-Oxo-pent-2-en-1-yliden)-indan-1-ones 2,4,6-Triarylpyrylium salts 1 react with indan-1-one in the presence of an appropriate buffer system (e.g. piperidine acetate, triethylamine/acetic acid, triethylamine or sodium acetate) to yield the 2-(1,3,5-triaryl-5-oxo-pent-2-en-1-yliden)-indan-1-ones 2 . For the reaction medium aliphatic alcohols (methanol, ethanol), dipolar aprotic solvents (acetonitrile) or chlorinated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride) can be used. On treating 2 with sodium methanolate in methanol, a cyclization reaction occurs giving rise to the 4-aroyl-1,3-diaryl-fluorenes 3 . As by-products 1,3-diaryl-fluorenes 8 (e.g. 1,3-diphenyl-fluorene) are formed. - I.r., n.m.r. and u.v. spectroscopic data of the novel compounds 2 and 3 are reported.     

Addition of arylureas to aroyl isothiocyanates and the synthesis of 1-aroyl-5-aryl-2-thiobiurets and 2-aryl-5-aroylamino-2,3-dihydro-1,2,4-thiadiazol-3-ones

The hitherto unknown 1-aroyl-5-aryl-2-thiobiurets ( 5a – h ) were synthesized by addition of mono arylureas ( 4 ) to aroyl isothiocyanates ( 3 ). Treatment of 1-aroyl-5-aryl-2-thiobiurets ( 5a – h ) with alkali gave 5-aryl-2-thiobiurets ( 6a – e ). Oxidation of 1-aroyl-5-aryl-2-thiobiurets ( 5d , f , h ) with hydrogen peroxide in the presence of hydrochloric acid or bromine in chloroform gave 2-aryl-5-aroylamino-2,3-dihydro-1,2,4-thiadiazol-3-ones ( 7a – c ).     

Cyclisierungsreaktionen β,γ-ungesättigter Kohlensäurederivate. VII. Synthese eindeutig N-acylierter Thiazolidin-2-one und Oxazolidin-2-one

Cyclization Reactions of β,γ-Unsaturated Derivatives of Carbonic Acid. VII. Synthesis of Unequivocal N-Acylated Thiazolidine-2-ones and Oxazolidine-2-ones A new synthetic route to N-acylated thiazolidine-2-ones and oxazolidine-2-ones is reported: The reaction of carboxylic acid chlorides with 2-alkoxy-2-thiazolines ( 1, 2 ) or -2-oxazolines ( 3 ) yields unequivocal N-acylated thiazolidine-2-ones ( 4–6 ) or oxazolidine-2-ones ( 7 ). Bifunctional acid chlorides, e.g. oxalyl chloride or thiophosgene yield compounds 11 and 12 .     

Facile and convenient synthesis of 2,4-disubstituted and 2,3,4-trisubstituted 1,3-thiazoles

An efficient route for the synthesis of (E)-2-(2-(2-nitrobenzylidene)-hydrazinyl)-4-phenylthiazol-3-ium bromide, (E)-2-(2(substituted benzylidene)hydrazinyl)-4-phenylthiazoles and (E)-4-(4-bromophenyl)-2-(cycloalkylidenehydrazono)-3-phenyl-2,3-dihydrothiazoles by reaction of 1-aryl-2-bromoethanones with 2-(1-substituted methylidene)hydrazinecarbothioamides and cycloalkylidene-N-phenyl-hydrazinecarbothioamides. The structure of the products has been confirmed by using IR, NMR, mass spectrometry and single-crystal X-ray analyses.     

Cyclisierungsreaktionen β,γ-ungesättigter Kohlensäurederivate. IX. Regiochemie der elektrophilen Cyclofunktionalisierung β,γ-ungesättigter Carbamidsäureester mit Brom – Synthese von Oxazolidin-2-onen und Tetrahydro-2H-1,3-oxazin-2-onen

Cyclization Reactions of β,γ-Unsaturated Derivatives of Carbonic Acid. IX. Regiochemistry of Electrophilic Cyclofunctionalization of β,γ-Unsaturated Carbamic Acid Esters with Bromine – Synthesis of Oxazolidine-2-ones and Tetrahydro-2H-1,3-oxazine-2-ones N,N-Disubstituted β,γ-unsaturated urethanes ( 1 ) and bromine react in methylene chloride at room temperature. The crotyl urethanes ( 1a – 1c and 1e ) and bromine give mixtures of corresponding saturated urethanes (dibromine adducts) ( 2a – 2c and 2e ), the oxazolidine-2-ones ( 3a – 3c and 3e ), and the tetrahydro-2H-1,3-oxazine-2-ones ( 4a – 4c and 4e ). The reaction of γ,γ-dimethylallyl urethanes ( 1f – 1h ) with bromine gives similar results. A useful synthetic route to N-substituted tetrahydro-2H-1,3-oxazine-2-ones ( 4l – 4q ) is demonstrated by the reaction of cinnamyl urethanes ( 1l – 1q ) with bromine.     

Cycloadditions-Eliminierungsreaktionen mit 4-Aryl-5-arylimino-1,2,4-dithiazolidin-3-onen (Senföloxiden)

Cycloaddition Elimination Reactions of 4-Aryl-5-arylimino-1,2,4-dithiazolidin-3-ones (Mustard Oil Oxides) 4-Aryl-5-arylimino-1,2,4-dithiazolidin-3-ones ( 1 ) react with isocyanates, isothiocyanates, and cyanic acid esters by exchange of the COS-part from 1 affording thiadiazole and dithiazole derivatives 4 , 5 , 6 or 12 . The reaction products are able to give further exchange reactions. Ring opening of 2-substituted 4-aryl-5-arylimino-1,2,4-thiadiazolin-3-ones ( 4 ) and -3-thiones ( 6 ) yields thio- and dithiobiurets ( 7 , 8 ) with aryl substituent in 3-position. Oxidation of dithiobiurets, generated from 6 , affords dithiazolidines 9 , which are Dimroth-isomers of 6 .     

r-5-(α-Halogenbenzyl)-3, t-4-diaryl-c-4-hydroxy-oxazolidin-2-one als Ringtautomere von α-(Arylaminocarbonyloxy)-β-halogen-dihydrochalkonen

r-5-(α-Halogenobenzyl)-3, t-4-diaryl-c-4-hydroxy-oxazolidin-2-ones as Ring Tautomers of α-(N-Arylaminocarbonyloxy)-β-halogeno-dihydrochalcones The reaction of chalcone halogenohydrins ( 1–3 ) with arylisocyanates does not stop at the stage of the α-arylaminocarbonyloxy-β-halogeno-dihydrochalcones ( 7 ), but the cyclic urethanes 4–6 are formed. Compound 7h was synthesized independently. The structure and stereochemistry of 4–6 and 7h were determined by ¹³C n.m.r. spectroscopy.     

Eine neue Synthese von 4,5-Dihydroxy-pyrazolen

A New Synthesis of 4,5-Dihydroxy-pyrazoles 1-Aryl-pyrazolin-5-ones 1 are converted by Knoevenagel condensation with acetone or by reaction with 2,2-dimethyl-1,3-dioxolane 6 to 1-aryl-4-isopropyliden-pyrazolin-5-ones 2 . The compounds 2 are epoxidized by hydrogen peroxide forming the spiro-epoxides 3 , which can be cleaved to 4,5-dihydroxy-pyrazoles 4 under acidic conditions. 4-Acetoxy-5-hydroxy-pyrazoles 13 are formed directly, when 3 are cleaved in presence of acetic anhydride. The 3,3′,3′-trimethyl-1-(4-nitro-phenyl)-pyrazolin-4-spiro-2′-oxiran-5-one 3b undergoes rearrangement to the 1,3-dioxolo[4,5-c]pyrazole 12 .     

Chalkonaziridine. III [1] Zur Reaktion von trans-Chalkonaziridinen mit Isocyanaten,Isothiocyanaten und HSCN

Chalcone Aziridines. III. Reaction of trans-Chalcone Aziridines with Isocyanates, Isothiocyanates and HSCN The reaction of 2-aryl-3-aroyl-aziridines 1 with phenyl isocyanate or mustard oils leads to N-phenylcarbamoyl derivatives 2a–2q and 2-amino-thiazolines 6 a, h, n, r , respectively. From 2 m and NaI the imidazolin-2-one 3 was obtained. By treatment of 2 with HSCN the regiosomeres 2(3)-ureido-3(2)-rhodano-1. 3-diaryl-propan-1-ones 4 a, h, m and 5 f were formed.     

1,3-Dipolar Cycloaddition Reactions between some C-aryl nitrogen oxides with electron-deficient dipolarophils

Both C-(2-methylphenyl)-N-phenyl and C-(3-methylphenyl)-N-phenyl nitrones ( 1a, b ) reacted with N-phenylmaleinimide and fumaronitrile to give the normal primary cycloadducts. The reaction of the two nitrones ( 1a, b ) with 4-phenyl-1,2,4-triazoline-3,5-dione and diacetylacetylene afforded rearrangement products. The unexpected 1,3,4-oxadiazolidin-2-ones were isolated from reaction with phenylisocyanate. In contrast, tetracyanoethylene forms charge-transfer complexes with both nitrones instead of cycloaddition products. The structural elucidation of the reaction products was made on the bases of the elemental analysis as well as i.r. and ¹H-n.m.r. spectral data.     

Cycloadditions-Eliminierungsreaktionen von Phenylisocyanat mit Oxo-und Thionoderivaten aliphatisch substituierter 5-Imino-1,2,4-dithiazolidine und 3-Thiono-1,2,4-thiadiazolidine (Senföloxide und Senfölsulfide)

Cycloaddition Elimination Reactions of Phenylisocyanate with Oxo and Thiono Derivatives of Aliphatic Substituted 5-Imino-1,2,4-dithiazolidines and 3-Thiono-1,2,4-thiadiazolidines (Mustard Oil Oxides and Sulfides) 5-Imino-1,2,4-dithiazolidin-3-ones 1 and-3-thiones 3 react with phenylisocyanate to afford 5-imino-1,2,4-thiadiazolidin-3-ones 6 . In comparison isomeric 3-thiono-1,2,4-thiadiazolidin-5-ones 2 , 5 , and -5-thiones 4 yield 3-imino-1,2,4-thiadiazolidin-5-ones 8 , 10 , and -5-thiones 7 . Thermolyses of thiadiazolidines 5 and 10 afford further 1,2,4-thiadiazolidines 9 , 11 . Compounds 8–11 are available also by reaction of substituted guanidines with chlorocarbonyl sulfenylchloride.     

Zur Heck-Reaktion von 1-Chloralk-1-inen – Synthese und Charakterisierung von 1,3-disubstituierten 7-(Prop-2-inyliden)bicyclo[2.2.1]heptanen und anderen Bicyclen

The Heck reaction of cyclohexene with 1-chloroalk-1-ynes ClC≡CR 1 (R = Ph a , c-Hex b , n-Bu c , n-Oct d ) using [Pd(OAc)₂]/NaO₂CH/[NEt₃Bz]Cl as catalyst system (DMF, 25 °C) affords 1,3-disubstituted 7-(prop-2-ynylidene)bicyclo[2.2.1]heptanes 2 as tandem products by reaction of cyclohexene and ClC≡CR in a ratio of 1:2. To a smaller extent, substituted 7-[(cyclohexenyl)methylidene]bicyclo-[2.2.1]heptanes 3 (tandem products by reaction of cyclohexene and ClC≡CR in a ratio of 2:1) and the regular Heck products (alkynylcyclohexenes 4 ) are formed. The homocoupling of 1 to give RC≡C–C≡CR does not take place, except for R = n-Oct where it proceeds as side reaction. The analogous reaction of ClC≡CR with cycloheptene affords the 2:1 products (substitued 8-[(cycloheptenyl)methylidene]biyclo[3.2.1]octanes 6 ) as main products and the 1:2 products (1,3-disubstituted 7-(prop-2-ynylidene)bicyclo[3.2.1]-octanes 5 ) as well as the regular Heck products (alkynylcycloheptenes 7 ) as side products. The ratio 5 : 6 is strongly influenced by the ratio cycloheptene : 1 . The products 2 , 5a and 6 were isolated and characterized by means of ¹H and ¹³C NMR spectroscopy. The molecular structures of 7-(1,3-diphenylprop-2-ynylidene)bicyclo[2.2.1]heptane ( 2a ) and 8-[(cyclo-heptenyl)phenylmethylidene)]bicyclo[3.2.1]octane ( 6a ) (as mixture of the cyclohept-3- and -4-enyl double bond isomers) were determined by single-crystal X-ray structure analysis.     

Reactions with 2-thiazolin 5-ones. IV. Action of amines on 4-substituted 2-alkoxy- and 2-benzylmercapto-2-thiazolin-5-ones

Whereas treatment of 2-butyloxy-, 2-pentyloxy- and 2-β-phenylethyloxy-4-arylazo-2-thiazolin-5-ones 1d–h with strong basic amines results in their rearrangement into 1-aryl- Δ²-1,2,4-triazolin-5-one-3-carboxylic acid derivatives 2 , the 2-isobutyloxy, 2-(2-octyloxy)- and the 2-cyclohexyloxy-4-arylazo-2-thiazoline-5-ones 1i–n rearrange upon treatment with the same reagents into Δ²- 1,2,4-triazoline-5-thione-3-carboxylic acid derivatives 3 . On the other hand, 1d–h,1 react with aromatic amines to give 1-aryl-2-alkoxy-1,2,4-triazole-3-carboxylic acid anilides 4a–i , via the loss of hydrogen sulphide. The phenylhydrazides 4j–l are obtained upon treatment of 1g, h,l with phenylhadrazine. Treatment of 4-arylidene-2-benzylmercapto-2-thiazolin-5-ones 6a–c with ammonia results in the formation of the thiohydantoin derivatives 7e, g . However, 6b, c react with phenylhydrazine to yield the phenylhydrazides 8b, c . The reaction of 6a–e with piperidine or morpholine involves to molecules of the reagent to yield 10a–d which are thermally cyclised to the thiazolone derivatives 11a–d .     

几个含噻二唑环芳甲酰基脲的合成及生物活性

通过2-氨基-5-(3-吡啶基)-1,3,4-噻二唑与取代苯甲酰基异氰酸酯反应,得到相应的芳甲酰基脲:N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(2-氯苯甲酰基)脲(Ⅲa)、N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(2-溴苯甲酰基)脲(Ⅲb)、N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(4-溴苯甲酰基)脲(Ⅲc)、N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(2-甲基苯甲酰基)脲(Ⅲd)和N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(4-三氟甲基苯甲酰基)脲(Ⅲe),收率分别为69.5%、67.2%、73.1%、66.8%和71.6%.产物的结构经红外光谱、核磁共振氢谱、质谱与元素分析表征.并对目标化合物进行了植物生长调节活性测试,初步的测试结果表明,目标化合物在10 mg/L表现出一定程度的生长素活性和较好的细胞分裂素活性,其中Ⅲc和Ⅲe的细胞分裂素活性超过40%.     

A convenient preparative method of unsymmetrical ketones and aliphatic aldehydes by thermolysis of homoallylic alcohols

The thermolyses of various homoallylic alcohols, which are prepared from 1-alken-4-ones (B) by Grignard reaction or reduction, afforded unsymmetrical ketones or aliphatic aldehydes in good yields. For example, the reaction of methylmagnesium iodide with 1-nonen-4-one (1) gave 4-methyl-1-nonen-4-ol (2) in 87% yield. The thermolysis of (2) at the temperature of 753 K gave 2-heptanone (3) in 92% yield. By use of this method, we obtained a variety of 1-alken-5-ones (J) which can be used as important intermediates of the preparation for dihydrojasmone or cis-jasmone.     

Zur Umkupplung von 4-Arylazo-2-pyrazolin-5-onen mit p-Chinondiiminkationen

Recoupling of 4-Arylazo-2-pyrazoline-5-ones with p-Quinonediimine Cations 4-Arylazo-2-pyrazoline-5-ones ( 1a – j ) readily undergo coupling reaction with p-quinonediimine cations ( 2a , b ) to form azomethin dyes ( 3a , b ). The dependence of the rate constants k_K of the dye formation on the substituents of 1a – j as well as on the ionic strength show that the rate-determining step of the coupling reaction is the formation of the intermediate 4 in a bimolecular reaction between the carbanions of 1a – j and p-quinonediimine ( 2a , b ). It became evident that the benzenediazoniumion ( 5a – j ) is eliminated in the reaction of 4 to 3a , b . Under the coupling conditions used, substituted benzene is formed in the reduction reaction of 5a , b by the p-phenylendiamine ( 7a , b ) or by the leuco dye ( 6a , b ).     

Reactions with 3,5-pyrazolidinediones. III. Cyanoethylation of Some 4-Arylazo Derivates of 3,5-Pyrazolidinediones and 3-amino-2-pyrazolin-5-ones

4-Arylazo-3,5-pyrazolidinediones 1 react with acrylonitrile to yield either 4-arylazo-1-β-cyanoethyl-3,5-pyrazolidinediones 2 or 4-arylazo-1,2-di-β-cyanoethyl-3,5-pyrazolidinediones 3 depending on the reaction conditions. Hydrolysis of 2 and 3 affords the corresponding acids 4 and 5 . Treatment of 4-arylhydrazono-3-amino-2-pyrazolin-5-ones 6 with acrylonitrile affords either the mono-β-cyanoethyl derivatives 7 or the pyrazolopyrimidine derivatives 10 depending on the reaction conditions.