摘要:

Abstractdl‐threo‐2‐Dichloroacetamido‐1‐[2‐(5‐bromobenzofuranyl)] propane‐1, 3‐diol (7) was synthesised according to Sorm's method. The fragmentation of 2‐dichloroacetamido‐3‐hydroxy‐1‐[2‐(5‐bromobenzofuranyl)[‐1‐propanone (6) under electron impact is reported. The base peak is due to the rupture of the central bond whereas loss of water and McLafferty rearrangement also lead

ISSN:0022-152X    

DOI:10.1002/jhet.5570190111

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractDiazotized anthranilic acid and its methyl ester react with substituted phenacyl thiocyanates3to give in both cases the corresponding thiadiazolo[2,3‐b]quinazolines7a‐e. A mechanism is proposed and it is substantiated by alternate synthesis of7afrom the hydrazidoyl chlorides9a,band potassium thiocyan

ISSN:0022-152X    

DOI:10.1002/jhet.5570190112

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractSynthesis and properties of hitherto unknown thiazolo[5,4‐d]pyrimidine 1‐oxides are described. For example, the reaction of 6‐chloro‐1,3‐dimethyl‐5‐nitrouracil (I) with methyl thioglycolate in the presence of excess triethylamine afforded 2‐methoxycarbonyl‐4,6‐dimethylthiazolo[5,4‐d]pyrimidine‐5,7‐(4H,6H)dione 1‐oxide (IIIa), which is a versatile intermediate for the preparation of various thiazolo[5

ISSN:0022-152X    

DOI:10.1002/jhet.5570190113

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractBeckmann rearrangement of alkylcyclooctenone oximes VIa and VIb gave corresponding nine‐membered lactams 1,3,4,5,8,9‐hexahydro‐3‐methyl‐2H‐azonin‐2‐one (VIIIa) and 1,3,4,5,8,9‐hexahydro‐3‐butyl‐2H‐azonin‐2‐one (VIIIb), respectively. A stereospecific transannular cyclization was induced by mercuric acetate leading to alkyl indolizinones Xa and Xb. Temperature and solvent dependent nmr spectra of the medium ring lactams indicates the stereochemical control is caused by steric interactions of the alkyl side chain. Lithium aluminum hydride reduced Xa/Xb tocis‐octahydro‐6‐methylindolizidine (XIa) andcis‐

ISSN:0022-152X    

DOI:10.1002/jhet.5570190114

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractThe mass spectral fragmentation patterns of thirteen 2′,3′ and 4′‐R‐trans‐2,4‐dinitrostilbenes obtained by electron impact have been studied. The main routes of fragmentation involves loss from the molecular ion due to theorthoeffects of the 2‐nitro substituents. Substitution on positions 2′,3′ and 4′ of stilbene moiety does not influence the f

ISSN:0022-152X    

DOI:10.1002/jhet.5570190115

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractStudies of compounds such as 1‐cyclohexyl‐2‐carbomethoxy‐4‐methylazetidine by H‐1 nmr coupling constants, nuclear Overhauser effects, C‐13 steric shifts, and N‐15 nmr support the revised assignment of configuration forcis/transisomers in a series ofN‐alkyl substituted azetidines. Thetransisomer displayed spectral characteristics consistent with a planar or nearly planar ring. Thecisisomer favors a puckered ring, with major substituents at C‐2 and C‐4 equatorial. Compounds lacking the C‐4 methyl are also puckered. Puckering angles are estimated. In contrast,trans‐1‐cyclohexyl‐2‐carboxy‐4‐methylazetidine (a zwitterion) prefers a puckered ring, possibly implicating the time averaged effect of nitrogen inversion on ring shape. The N‐15 spectra show a large difference in chemical shift betweencisandtransisomers of the azetidines, although analogous azir

ISSN:0022-152X    

DOI:10.1002/jhet.5570190116

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractLes perchlorates de phényl‐3 benzopyrylium‐1 (1a) et (1i) réagissent exclusivement en position 2 avec l'éthanol et l'alcool isopropylique pour donner les acétals mixtes2a, 3aet3i. En présence deN‐nucléophiles, les sels1aet1bdonnent avec l'ammoniaque les amines secondaires symétriques4aet4bou bis(phényl‐3 2Hbenzopyranne‐1 yl‐2)amines, tandis qu'avec les amines aliphatiques en solution aqueuse il se forme les bis‐acétals5aet5bou oxy‐2,2′ bis(phényl‐3 2Hbenzopyrannes‐1). Ces mêmes dérivés5aet5bsont obtenus dans

ISSN:0022-152X    

DOI:10.1002/jhet.5570190117

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractThe title compound (3), a β‐ketosulfoxide prepared by a Claisen‐type condensation of ethyl 2‐(10‐phenothiazino)acetate (4) with dimsyl carbanion, was subjected to a variety of catalysts in attempts to achieve a Pummerer cyclization to 1,2‐dihydro‐3‐methylthio‐2‐oxo‐3H‐pyrido[3,2,1‐kl]phenothiazine (2). Although the Pummerer rearrangement product, 10‐(2‐oxo‐3‐hydroxy‐3‐methylthiopropyl)phenothiazine (5), could be obtained in excellent yield under mild conditions, neither it nor the β‐ketosulfoxide could be successfully cyclized under any of the conditions attempted. Instead, phenothiazine, 2‐hyroxy‐3‐(10‐phenothiazinyl)‐2‐propen‐1‐al (7), 3‐(10‐phenothiazinyl)‐1,1‐di(methylthio)propan‐2‐one (8), 3‐(10‐phenothiazinyl)‐1‐methylthiop

ISSN:0022-152X    

DOI:10.1002/jhet.5570190118

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractThe 70 eV electron impact mass spectra of twenty‐five 1,5‐benzodiazepines are discussed in detail with the aid of metastable ions and by comparison with the fragmentation patterns of known compounds. The fragmentation is markedly influenced byortho‐substituents on the aniline

ISSN:0022-152X    

DOI:10.1002/jhet.5570190119

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY

摘要:

AbstractA series of 1,2‐dihydro‐4H‐2‐phenyl‐3,1‐benzoxazines (I) were obtained by condensation ofo‐aminobenzyl alcohol and substituted benzaldehyde. The effect ofp‐substitution on their spectroscopic properties was investigated by uv and ma

ISSN:0022-152X    

DOI:10.1002/jhet.5570190120

出版商:Wiley‐Blackwell    

年代:1982

数据来源: WILEY