摘要:

AbstractSchiff's bases1derived from ketones andt‐butylamine reacted with diphenyl malonate, diphenyl methyl‐malonate and diphenyl phenylmalonate to give 4‐hydroxy‐2‐pyridones4–6. Schiff's basesbon reaction with trimethyl methanetricarboxylate afforded 4‐hydroxy‐3‐methoxycarbo

ISSN:0022-152X    

DOI:10.1002/jhet.5570290501

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

Abstract6‐Amino‐2,3‐dihydro‐2‐thioxo‐4(1H)‐pyrimidinone (1) reacts in boiling DMF with α,/β‐unsaturated ketones 2 yielding the pyrido[2,3‐d]pyrimidine systems 5 and 6, respectively. The orientation in the addition process can be determined by nmr measurements, especially by NOE difference spectroscopy. The products do not correspond to a normal Skraup or Doebner

ISSN:0022-152X    

DOI:10.1002/jhet.5570290502

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractSubstituted biaryl compounds9, 14–16were synthesized through Pd(0)‐catalyzed cross coupling reactions between boronic acids or tin derivatives and aryl halides.N‐Amination, and subsequent ring closure resulted in the new angularly‐fused pyrido[1,2‐b]pyridazinium systems1–4. The use of silver oxide as a cocatalyst in the couplings of tin derivatives was essential in order to obtain rapid reaction and better yields. Structures were determined by1H nmr and13C

ISSN:0022-152X    

DOI:10.1002/jhet.5570290503

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractAromatic ketones react with 3‐mercapto‐1,2‐propanediol (1) in refluxing benzene under the catalytic influence of a sulfonic acid and with azeotropic removal of water to yield a mixture comprised predominantly ofcis‐ andtrans‐2‐alkyl‐2‐aryl‐1,3‐oxathiolane‐5‐methanols 7, accompanied by lesser amounts ofcis‐ andtrans‐2‐alkyl‐2‐aryl‐1,3‐dioxolane‐4‐methanethiols8(up to 30%). It was discovered that8is the kinetic product and is isomerized by 4‐toluenesulfonic acid in hot benzene to the thermodynamically more stable7. Under these conditions,ortho‐ and α‐substituted aromatic ketones tend to produce more of8, which can be attributed to steric hindrance encountered by the thiol as it attacks the ketone. Ketalizations of 1‐aryl‐2‐(1H‐imidazol‐1‐yl)‐1‐ as well as 1‐aryl‐2‐(1,H‐1,2,4‐triazol‐1‐yl)‐1‐ethanones by 1 fail under these conditions, even after 24 hours of reflux in toluene. However, 1‐(4‐chlorophenyl)‐3‐(1H‐imidazol‐1‐yl)‐1‐propanone and 1‐(4‐bromophenyl)‐4‐(1H‐imidazol‐1‐yl)‐1‐butanone are ketalized by1as expected. Interestingly, the reaction of 2‐bromo‐4′‐chloroace‐tophenone with1produces 1‐(4‐chlorophenyl)‐2,8‐dioxa‐6‐thiabicyclo[3.2.1]octane. Characterization of all isomers and separation of s

ISSN:0022-152X    

DOI:10.1002/jhet.5570290504

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractN‐Cyanovinyl‐lactam imines2react with hydrazine giving aminopyrazole4awhile lactam imine3is split off. Treatment of2with strong bases gives intramolecular cyclization to condensed 4‐aminopyridines5. The progress of reaction was observed by polarographic m

ISSN:0022-152X    

DOI:10.1002/jhet.5570290505

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractReactions of 3‐methyl‐6‐[4‐(4‐hydroxyphenyl)‐1‐piperazinyl]‐2(3H)‐benzoxazolone, 3‐methyl‐6‐[4‐(4‐hydroxy‐phenyl)‐1‐piperazinyl]‐2(3H)‐benzothiazolone and 1,3‐dimethyl‐5‐[4‐(4‐hydroxyphenyl)‐1‐piperazinyl]‐2(3H)‐benzimidazolone withcis‐{[2‐(2,4‐dichlorophenyl) ‐2‐(1H‐imidazol‐1‐ylmethyl)]‐1,3‐dioxolan‐4‐yl}methyl

ISSN:0022-152X    

DOI:10.1002/jhet.5570290506

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractThe coupling reactions of some organocopper reagents with 3‐bromo‐2,5‐dimethylthiophene 1,1‐dioxide leading to 3‐alkyl and 3‐aryl substituted 2,5‐dimethylthiophene 1,1‐dioxides have been found to proceed in high yields (50–100%). The less stable organocopper reagents reacted faster and at lower temperatures than the more stable ones. It is more convenient to use alkylcopper than lithium dialkylcuprate reagents, which give higher yields witho

ISSN:0022-152X    

DOI:10.1002/jhet.5570290507

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

Abstract5‐Aryl(or benzyl)‐3‐(2‐bromoethyl)‐1,3,4‐oxadiazol‐2(3H)‐ones3have been prepared. They were reacted with secondary alkylamines without any change of the heterocycle to give amino derivatives6, but with primary alkylamines, cyclic transformation occurred to give 1‐acylamino‐3‐alkylimidazolidin‐2‐ones7. In the presence of sodium alcoholate, bromo compounds3were transformed into 2‐aryl(or benzyl)‐4‐alkoxycarbonyl‐

ISSN:0022-152X    

DOI:10.1002/jhet.5570290508

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractAllyl α‐phenyl‐2‐aminophenethyl carbonates undergo a smooth decarboxylation‐dehydrogenation reaction to afford 2‐phenylindole derivatives in acetonitrile at 80° in the presence of palladium complex as catalyst. In the reaction, the ruthenium hydride complex showed more effective catalytic activities. 2‐Phenylindoles were also prepared from the corresponding α‐phenyl‐2‐aminophenethylalcohols and allyl methyl carbonate by ruthenium

ISSN:0022-152X    

DOI:10.1002/jhet.5570290509

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY

摘要:

AbstractThe conditions required for selective lithiation at the 2‐position of 4,5‐dicyanoimidazoles are described in detail. The course of the reaction of alkyllithium reagents with 4,5‐dicyanoimidazoles depends on the temperature, the number of equivalents of alkyllithium and whether the 1‐nitrogen is protected. Under certain circumstances, the alkyllithium reagent adds to one of the cyano groups giving cyanoimidazole

ISSN:0022-152X    

DOI:10.1002/jhet.5570290510

出版商:Wiley‐Blackwell    

年代:1992

数据来源: WILEY