摘要:

AbstractAnalogues of deoxyvasicinone (1) in which the pyrrolo ring is substituted, enlarged, or attached to the a face of the quinazolone system were prepared and several reactions of these analogues with electrophilic reagents have been investigated.

ISSN:0022-152X    

DOI:10.1002/jhet.5570230111

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract6‐Amino‐1‐(2‐deoxy‐β‐D‐erthro‐pentofuranosyl)pyrazolo[4,3‐c]pyridin‐4(5H)‐one (5), as well as 2‐(β‐D‐ribofuranosyl)‐ and 2‐(2‐deoxy‐β‐D‐ribofuranosyl)‐ derivatives of 6‐aminopyrazolo[4,3‐c]pyridin‐4(5H)‐one (18and22, respectively) have been synthesized by a base‐catalyzed ring closure of pyrazole nucleoside precursors. Glycosylation of the sodium salt of methyl 3(5)‐cyanomethylpyrazole‐4‐carboxylate (6) with 1‐chloro‐2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranose (8) provided the corresponding N‐1 and N‐2 glycosyl derivatives (9and10, respectively). Debenzoylation of9and10with sodium methoxide gave deprotected nucleosides14and16, respectively. Further ammonolysis of14and16afforded 5(or 3)‐cyanomethyl‐1‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)pyrazole‐4‐carboxamide (15and17, respectively). Ring closure of15and17in the presence of sodium carbonate gave5and22, respectively. By contrast, glycosylation of the sodium salt of6with 2,3,5‐tri‐O‐benzoyl‐D‐ribofuranosyl bromide (11) or the persilylated6with 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose gave mainly the N‐2 glycosylated derivative13, which on ammonolysis and ring closure furnished18. Phosphorylation of18gave 6‐amino‐2‐β‐D‐ribofuranosylpyrazolo[4,3‐c]pyridin‐4(5H)‐one 5′‐phosphate (19). The site of glycosylation and

ISSN:0022-152X    

DOI:10.1002/jhet.5570230112

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractThe title compounds9–12were prepared fromN‐(8‐nitronaphthyl)pyrrol

ISSN:0022-152X    

DOI:10.1002/jhet.5570230113

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractHeterocyclic compounds of four 6‐phenyl‐5,6,7,8‐tetrahydro‐4H‐1,3,6‐dioxazocines have been synthesized by condensation of the correspondingN,N‐bis(2‐hydroxyethyl)‐ orN,N‐bis(2‐hydroxypropyl)anilines with aldehyde or ketone in the presence of acid. The pmr and cmr spectra of these compounds were recorded to determine their stereochemical structures. On the basis of the chemical shifts due to the γ‐effects, the stereochemical

ISSN:0022-152X    

DOI:10.1002/jhet.5570230114

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractHydrochloride salts ofN‐substituted‐bis‐(2‐chloroethyl)amines can be condensed withm‐methoxyphenyl‐acetonitrile or 1‐phenyl‐2‐alkanones under phase‐transfer conditions to yield precursors of the powerful analgesic compounds

ISSN:0022-152X    

DOI:10.1002/jhet.5570230115

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstractβ‐Keto‐β‐sulfonylenamines2a,breacted with benzamidine or guanidines to give 2,4‐disubstituted 5‐methanesulfonylpyrimidines3a‐d, whose methanesulfonyl groups were substituted byn‐butyllithium or alkylmagnesium bromides to yield 2,4‐disubstitued 5‐alkylpyrimidines6a‐d.2‐Substituted 4‐amino‐5‐sulfonylpyrimidines7a,b, 8and 2‐substituted 5‐benzenesulfonylpyrimidin‐4‐ones9a,bwere similarly obtained from β‐cyano‐β‐sulfonylenamines2c,dand β‐eth

ISSN:0022-152X    

DOI:10.1002/jhet.5570230116

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractNormally borane reduces lactones too rapidly to allow the isolation of intermediates but 4‐(trinitromethyl)‐tetrahydro‐2‐furanol and 4‐(fluorodinitromethyl)tetrahydro‐2‐furanol are isolated in 72 and 36% yield from the reduction of 4‐hydroxy‐3‐(trinitromethyl)butyric acid, γ‐lactone and 4‐hydroxy‐3‐(fluorodinitromethyl)‐butyric acid, γ‐lactone with borane‐tetrahydrofuran complex. The preparation of 2‐polynitroalkoxy‐4‐polynitromethyltetrahyd

ISSN:0022-152X    

DOI:10.1002/jhet.5570230117

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractA general procedure for the preparation of aminocoumarins and aminohydroxycoumarins under mild conditions is described. Amino‐ and acetamidoaminocoumarins were prepared by reduction of the corresponding nitro derivatives with sodium borohydride in the presence of 10% palladium on charcoal. Acid hydrolysis of the acetamidoaminocoumarins with (a) concentrated hydrochloric acid in ethanol, or (b) with 1Nhydrochloric acid under reflux, gave diaminocoumarins and aminohydroxycoumarins, respectively. Condensation of the ethyl ester of glycine with salicylaldehyde gave 3‐salicylideneaminocoumarin (XIII), the Schiff base of 3‐aminocoumarin (XII). Acid hydrolysis of XIII under the above mentioned conditions, (a) and (b), gave XII and 3‐hydroxycoumarin (XVI), respectively. Hydrogenation of compound XIII in dioxane or in dimethylformamide with 10% palladium on charcoal gave 3‐salicylaminocoumarin (XVII), while hydrogenation of XII, XIII or XVII in acetic acid with traces of water and palladium black gave the amino acido

ISSN:0022-152X    

DOI:10.1002/jhet.5570230118

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractA novel approach to the title ring system starting with conveniently available cinnamoylacetonitrile (1) is proposed. It involves the Japp‐Klingemann reaction of1followed by thermally induced cyclisation of hydrazones2and subsequent addition of the resulting pyridazine derivatives3to 2‐substituted cinnamonitriles4a, 4b.The structures of the pyrano[2,3‐d]pyridazines5a, 5b, thus obtained, were established on basis of spectroscopic

ISSN:0022-152X    

DOI:10.1002/jhet.5570230119

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractA novel system 2‐oxo‐1′,2′,4′,5′‐tetrahydrospiro[3H‐indole‐3,3′‐1,2,4,5‐tetrazine]‐6′‐thione has been synthesized by the treatment of fluorinated isatins with thiocarbohydrazide in aqueous ethanolic medium. Under exactly similar conditions,N‐acetylisatin gave exclusively thiocarbohydrazone. The spiro product, on treatment with acetic acid, gave fluorinated isoindigo. Characterization of these products have been done by elemental analyses, ir

ISSN:0022-152X    

DOI:10.1002/jhet.5570230120

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY