摘要:

About the Reaction between Hydrazines and Aminohydroxy‐hydrobenzoxazol. Synthesis of AzoolefinesBy the reaction of 1‐hydroxy‐2‐oxocyclohexane‐carboxamide (1) with cyanamide 2‐amino‐7a‐carbamoyl‐3a‐hydroxy‐3a,4a,5,6,7,7a‐hexahydrobenzoxazole (2) is formed. Compound2and arylhydrazine‐hydrochloride yield 1‐carbamoyl‐2‐arylazocyclohex‐1‐ene (4a,b). In morpholine azocompounds4a,brearrange to hydrazones5a,b. Compound2and hydrazine yield 4‐(2‐carbamoyl‐cyclohexyl)‐semicarbazide (10),10forms perhydroquinazoline‐2,4‐dione (11) by oxidation with iodine.2and cyanic acid yield the urea derivative12.2and arylamine‐hydrochloride afford the 2‐arylamino‐3a‐hydroxy‐7a‐carbamoyl‐hexahydrobenzoxazoles13a,b. By fragmentation and “Dimroth‐rearrangement” of2tetrahydrobenzoimidazolone, (14) is formed,12gives 1‐carbamoyl‐tetrahydrobenzoimidazolone (15).2and m‐nitrobenzaldehyde yield “Schiff‐base”16.2and hydroxylamine sulphate form 2′‐amino‐2‐hydroximino‐cyclohexane‐spiro‐5′‐oxazolin‐4

ISSN:0021-8383    

DOI:10.1002/prac.19873290202

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

A Ring Contraction Induced by Hydrogenperoxide2‐Amino‐7a‐carbamoyl‐3a‐hydroxy‐3a,4,5,6,7,7a‐hexahydro‐benzoxazole (1) and hydrogenperoxide rearrange to 2′‐amino‐cyclopentanespiro‐5′‐oxazolin‐4′‐one (5).5and aniline hydrochloride form the phenylaminoderivative6,5and 2,5‐dichlorophenylhydrazine hydrochloride form the 2,5‐dichlorophenylhydrazinederivative7.5and hydrochloric acid afford cyclopentanespiro‐5′‐oxazolidin‐2′,4′‐dione (8). Hydrolysis of5or

ISSN:0021-8383    

DOI:10.1002/prac.19873290203

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe cyclic tetramer ofN‐methyleneaniline, one of the products from the condensation between formaldehyde and aniline under neutral condition, has been characterized as 1.3.5.7‐tetraphenyltetrazocine (3) and its crystal structure elucidated by X‐ray diffra

ISSN:0021-8383    

DOI:10.1002/prac.19873290204

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19873290205

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractA reported preparation of 1,3‐dicyclohexyl‐1,3‐diazacyclobutane (2) is rebutted: the correct structure is that of N′,N″,N″′‐tricyclohexylhexahydro‐sym‐triazine (5), having a diequatorial‐axial conformation in the solid state, as shown by mass spectrometry and X‐ray diffraction. Theoretical calculations were carried out in order to predict the stabilities of 1,2‐ and 1,3‐diazacyclobutane (1

ISSN:0021-8383    

DOI:10.1002/prac.19873290206

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe 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‐aroyla

ISSN:0021-8383    

DOI:10.1002/prac.19873290207

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractReaction of 5,6‐dihydro‐5‐azacytidine hydrochloride1with 2‐acetoxy‐isobutyryl chloride produced 5′‐O‐(2,5,5‐trimethyl‐1,3‐dioxolan‐4‐on‐2‐yl)‐3′‐O‐acetyl‐5,6‐dihydro‐2,2′‐anhydro‐1‐β‐D‐arabinofuranosyl‐5‐azacytosine hydrochloride2, which upon partial hydrolysis with EtOH/HCl at 4°C gave 3′‐O‐acetyl‐5,6‐dihydro‐2,2′‐anhydro‐1‐β‐D‐arabinofuranosyl‐5‐azacytosine hydrochloride3. The hydrolysis of3with EtOH/HCl at 25°C gave 2,2′‐anhydro‐5,6‐dihydro‐1‐β‐D‐arabinofuranosyl‐5‐azacytosine hydrochloride4. Silylation oxidation of3and4with BSTFA or BSA i

ISSN:0021-8383    

DOI:10.1002/prac.19873290208

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19873290209

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

On the Coupling of 4‐Substituted 2‐Pyrazoline‐5‐ones with Quinone Diimine Cations; Detection of Isokinetic RelationsThe temperature dependence of the rate constant kKof the coupling reaction between pyrazoline‐5‐ones1a–iand quinone diimine cations2a,bis determined in dependence of the substituents at the coupling position (R3: H, NNAr,CHAr–pyrazoline‐5‐one). The activation enthalpies are between 7 and 60 kJ mol−1and the activation entropies between −132 and −19 J mol−1K−1. An isokinetic relation with β = 106°C is found and a rate determining combination of the carbanions of1a–iwith2a,bis proposed. Contrary to this, the 2‐pyrazolin‐5‐ones1j–l,n(R3: SCNH2NR) obey an isokinetic relation with β = −45°C. Taking into consideration the activation parameters, the low dependence of kKon the ionic strength, and the decrease of kKwith the increase of the pK values of t

ISSN:0021-8383    

DOI:10.1002/prac.19873290210

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractRaman spectroscopic and conductivity studies show that pyridinium derivatives of the TlCl52⊖, TlCl63⊖and Tl2Cl93⊖species dissociate in ethanol solution to yield the TlCl4⊖ion, but the [(C2H5)4N]2TlCl5salt does not dissociate further and behaves like a 2:1 elec

ISSN:0021-8383    

DOI:10.1002/prac.19873290211

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY