摘要:

AbstractThe synthesis of 5,10‐dideazaaminopterin by two independent routes is described. Condensation of the piperidine enamine of 4‐p‐carbomethoxyphenylbutyraldehyde (4) with ethoxymethylenemalononitrile followed by treatment of the resultant arylethylenaminomalononitrile (5) with methanolic ammonia produced 2‐amino‐3‐cyano‐5‐p‐carbomethoxyphenethylpyridine (6). Cyclization of the aminocyanopyridine with guanidine afforded 4‐amino‐4‐deoxy‐5,10‐dideazapteroic acid (8). Coupling of the pteroate intermediate with glutamate yielded the target 5,10‐dideazaaminopterin (10).Alternatively, reduction of 2,4‐diamino‐6‐formyl‐5‐deazapteridine (11) with sodium borohydride gave the 6‐hydroxymethyl compound12. Conversion to the bromide was followed by alkylation of dimethyl homoterephthalate to afford methyl 4‐amino‐4‐deoxy‐10‐carbomethoxy‐5,10‐dideazapteroate (14). Decarboxylation with ester cleavage (sodium cyanide in dimethyl sulfoxide at 180°) also gave the diaminopteroic acid (8).5,10‐dideazaaminopterin (10) was an effective growth i

ISSN:0022-152X    

DOI:10.1002/jhet.5570230101

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract2‐Hydroxymethyl‐5‐methoxy‐4‐H‐pyran‐4‐one (1) reacts with aniline and six aniline derivatives in very dilute aqueous hydrochloric acid at reflux temperature to give theN‐aryl‐γ‐pyridone. A second procedure utilizes the aromatic amine hydrochloride by reacting it with1in aqueous medium at reflux temperature.p‐Nitroaniline hydrochloride and1give theN‐aryl‐γ‐pyridone in 65% yield, as opposed to 12%

ISSN:0022-152X    

DOI:10.1002/jhet.5570230102

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractThe acidity of 5‐benzylbarbituric acid and a series of 5‐substituted benzylbarbituric acids has been determined in 50% ethanol/water and they were found to be more acidic than barbituric acid. The pKas of these derivatives obey Hammett's equation indicating that their acidity is affected by substituents in the same manner as the benzoic acid ionization constants. A synthesis of these acids is descri

ISSN:0022-152X    

DOI:10.1002/jhet.5570230103

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract1,4‐Diphenylphthalazine (1) was reduced in tetrahydrofuran by sodium metal to a monomeric dianion2. Chemical reactions of this new dianion were examined with various reagents. Generally, the protonation, acylation and alkylation products were 1,2‐dihydrophthalazine derivatives. An annulation of the phthalazine ring system was accomplished by treating the dianion with 1,3‐dichloropropane or 1,4‐dichlorobutane. With 1,2‐dichloroethane however, only 1,4‐diphenylnaphthalene w

ISSN:0022-152X    

DOI:10.1002/jhet.5570230104

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractLa réactivité de la pyrrolo[1,2‐a]thiéno[2,3‐e]pyrazine1est étudiée vis à vis des réactions de quaternarisation, bromation, nitration, Friedel‐Crafts, Vilsmeier‐Haack et de Reissert. La structure des produits obtenus est déduite de l'analyse de leur spectre de rmn ou de masse ou par sy

ISSN:0022-152X    

DOI:10.1002/jhet.5570230105

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractThe direct synthesis of a new class of unknown 1‐heterocyclamino‐3‐carbonylpyrroles and 1‐heterocyclamino‐3‐carboxypyrroles by copper(II) chloride‐catalyzed reaction of heterocyclic conjugated azoalkene derivatives with β‐diketones and β‐ket

ISSN:0022-152X    

DOI:10.1002/jhet.5570230106

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract8‐Quinolinols which are substituted in the aromatic nucleus by nitro‐, chloro‐, or by sulfonic acid groups underwent a neat thermal fragmentation upon heating in 75% nitric acid as reaction medium yielding 2,3‐dicarboxypyridinium nitrate. The scope and the mechanism of these reactions are di

ISSN:0022-152X    

DOI:10.1002/jhet.5570230107

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractThe first examples of the unknown pyrazino[2,3‐e]‐as‐triazine ring system, that is, the 6,7‐dihydroxy‐5,6,7,8‐tetrahydropyrazino[2,3‐e]‐as‐triazines, have been prepared by ring closure of selected 5,6‐diamino‐as‐triazines with 40% aqueous glyoxal. These 4‐azapteridines experience a novel exchange process with alcohols at the C(7)‐position. When dissolved in alcohol and stirred at room temperature, the 7‐alkoxy, 6‐hydroxy analogues are formed and isolated. In fact, during ring closure, if alcohols are used as the solvent, only the latter compounds are obtained. Initially, cyclization of theortho‐diamino‐as‐triazines with glyoxal proceeds in a stereoselective manner giving rise to both thecisandtransadducts. A single‐crystal X‐ray diffraction study has determined the predominant and most stable adduct to be thetrans (R,RorS,S)isomer. Spectroscopy (nmr) has verified the intermediacy of thecisadduct, but because of the aforementioned exchange process only thetransisomer is isolated. The site of exchange on these σ‐adducts has been rigorously established as C(7). A plausible reaction mechanism by whi

ISSN:0022-152X    

DOI:10.1002/jhet.5570230108

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract2‐Aryl‐4‐thioxo‐1,3‐benzothiazines react with thiocarbohydrazide to give the new mesoionic compounds an‐hydro 1‐amino‐5‐aryl‐2‐mercapto‐1,3,4‐triazolo[3,2‐c]quinazolin‐4‐ium hydroxides. These compounds react with methyl iodide, aldehydes and phenacyl bromides to give 1‐amino‐5‐aryl‐2‐methylthio‐1,3,4‐triazolo‐[3,2‐c]quinazolin‐4‐ium iodides, 4‐arylidenamino‐3‐(o‐aroylamino)phenyl‐1H‐1,2,4‐triazolin‐5‐thiones and 3‐(o‐aroylamino)phenyl‐6‐aryl‐7H‐1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazines, respectively. These latter compounds by sequential treatment with methyl trifluoromethanesulphonate and triethylamine le

ISSN:0022-152X    

DOI:10.1002/jhet.5570230109

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractTropone benzoyl‐ and tosylhydrazones underwent the [8+2] cycloaddition reaction with isocyanates to afford the cyclohepta[d]imidazolin‐2‐one derivatives. This means that these hydrazones behaved as 8‐amino‐8‐azaheptafulvenes. Also, the tropone hydrazones reacted with phenylketene and phenylsulfene in more complica

ISSN:0022-152X    

DOI:10.1002/jhet.5570230110

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY