2, 5-二取代基-1, 3, 4-恶二唑及恶二唑啉类化合物的合成

2-苯基-1,2,3-连三唑-4-甲酰肼(1)与芳酸在POCl~3催化下得到6种新的2-芳基-5-(2'-苯基-1',2',3'-连三唑-4'-基)-1,3,4-恶二唑(2)。1与羰基化合物缩合得到相应的酰腙(3),在Ac~2O作用下环化成2-取代基-3-乙酰基-5-(2'-苯基-1',2',3'-连三唑-4'-基)-1,3,4-恶二唑啉(4)。化合物的结构经元素分析,IR,^1HNMR和MS确证。     

One-stage conversion of aromatic carboxylic acids into 2, 5-diaryl-1, 3, 4-oxadiazoles

A method has been developed for the one-stage conversion of aromatic carboxylic acids into symmetrical 2, 5-diaryl-1, 3, 4-oxadiazoles by heating them with hydrazine hydrochloride in polyphosphoric acid.     

2-芳基-5-(5-苯基-2H-四唑-2-亚甲基)-1,3,4-噁二唑类化合物的研究

作者曾研究2-芳基-5-(2-苯基-4-喹啉基)-1,3,4-噁二唑类衍生物,并发现它们具有促进小麦发芽生长的功效。Juby和Shan等报道某些四唑类化合物具有消炎性     

Vinyl derivatives of 2, 5-diaryl-1, 3,4-oxadiazoles

Vinyl derivatives of 2, 5-diaryl-1, 3, 4-oxadiazoles have been synthesized and some of their physical properties have been studied.     

Vinyl derivatives of 2, 5-diaryl-1, 3,4-oxadiazoles

Vinyl derivatives of 2, 5-diaryl-1, 3, 4-oxadiazoles have been synthesized and some of their physical properties have been studied.     

Synthesis of 2,5-Dialkyl-1,3,4-oxadiazoles Bearing Carboxymethylamino Groups

A series of new symmetrical 2,5-dialkyl-1,3,4-oxadiazoles containing substituted alkyl groups at the terminal positions with substituents, such as bromine, isopropyloxycarbonylmethylamino, and carboxymethylamino, were successfully synthesized. The developed multistep method employed commercially available acid chlorides differing in alkyl chain length and terminal substituent, hydrazine hydrate, and phosphorus oxychloride. The intermediate bromine-containing 2,5-dialkyl-1,3,4-oxadiazoles were easily substituted with diisopropyl iminodiacetate, followed by hydrolysis in aqueous methanol solution giving the corresponding 1,3,4-oxadiazoles bearing carboxymethylamino substituents. The structure of all products was confirmed by conventional spectroscopic methods including ¹H NMR, ¹³C NMR, and HRMS.     

2-芳基-5-(2-苯基-4-喹啉基)-1,3,4-恶二唑衍生物的合成及其相关性质的研究

1,3,4-恶二唑衍生物在医药,农药、染料、涂料、高分子合成材料以及有机闪烁体材料等方面有广泛用途。近年来有关合成和生理活性的研究报道甚多。本文选择被淘汰的解热镇痛、去风湿药物     

Synthesis and study of poly (1, 3, 4-oxadiazoles)

Various conditions for synthesizing poly (1,3,4-oxadiazoles) from carboxylic acids, their hydrazides, and polyhydrazides, are investigated. Methods of cyclodehydration of polyhydrazides using phosphorus oxychloride, sulfuric acid, and certain other reagents are not of general utility for synthesizing poly (1,3,4-oxadiazoles). Vacuum-heating polyhydrazides gives crosslinked polymers. A new method of preparing poly (1,3,4-oxadiazoles) is offered. It is the reaction of hydrazine sulfate or dihydrazides of acids with dicarboxylic acids in oleum solution. Some chemical properties of the compounds synthesized are investigated.     

1,1-Dialkyl-2-acyl-3-hydroxypyrazolidinium and 2,2-dialkyl-5-hydroxyisoxazolidinium salts

Salts of 1,1-dimethyl-2-acylhydrazines and 1,1-dialkylhydroxylamines add quantitatively to the double bond of oxo compounds with an unsubstituted vinyl substituent. The structure of the products depends on the nature of the substituent at the carbonyl group.¹H and¹³C NMR spectroscopy indicated that acrolein derivatives have the cyclic structure of 1,1-dialkyl-2-acyl-3-hydroxypyrazolidinium and 2,2-dialkyl-5-hydroxyisoxazolidinium salts, while derivatives of phenyl vinyl ketone and hydrazide salts are the corresponding linear, hydrazinium salts. Ring-chain tautomerism was found for several derivatives of methyl vinyl ketone in solution.Military Medical Academy, 194175 St. Petersburg. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1199–1203, September, 1998.     

Synthesis of Alkyl 5,6-Dialkyl-2-amino-3-cyanopyridine-4-carboxylates

An unusual route has been found for the hydrolysis of 3-amino-1,1-dialkoxy-6,7-dialkyl-4-aryl-3a,4,5,7a-tetrahydro-1H-pyrrolo[3,4-c]pyridine-3a,7a-dicarbonitriles in acidic medium which leads to the formation of alkyl 5,6-dialkyl-2-amino-3-cyanopyridine-4-carboxylates.     

1-取代酰基-4-磷酰基氨基硫脲及其1, 3, 4-恶二唑杂环衍生物 的合成

合成了1-取代酰基-4-磷酰基氨基硫脲(5),以及由(5)衍生的环化产物2-磷酰氨基-5-苯基(或氰乙基)-1,3,4-恶二唑(6),它们的结构经^1HNMR,IR和元素分析的证实。初步生测结果表明,部分化事物具有一定的植物生长调节活性和除草活性。     

Conversion of 2, 5-diphenyl-1, 3,4-oxadiazole to 3, 5-diphenyl-4-aryl-1, 2, 4-triazoles

2, 5-Diphenyl-1, 3, 4-oxadiazoles are shown to react with aromatic amines on heating, to give 2, 5-diphenyl-4-aryl-1, 2, 4-triazoles.     

Conversion of 2, 5-diphenyl-1, 3,4-oxadiazole to 3, 5-diphenyl-4-aryl-1, 2, 4-triazoles

2, 5-Diphenyl-1, 3, 4-oxadiazoles are shown to react with aromatic amines on heating, to give 2, 5-diphenyl-4-aryl-1, 2, 4-triazoles.     

Synthesis of 3-methyl-4-(5-R-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazoles

A number of 3-methyl-4-(5-R-1H-1,2,4-triazol-3-yl)-1,2,5-oxadiazoles were obtained in high yields by thermal dehydration of acylated 4-methyl-1,2,5-oxadiazole-3-carboxamide hydrazones.     

Facile Synthesis of 1,2-Dialkyl-3-Phenyl-4-Quinolinones

The synthesis of 1,2-dialkyl-3-phenyl-4-quinolinones (1) is readily accomplished by a low-temperature reaction of an N-alkylisatoic anhydride with the therraodynamic potassium enolate of phenyl-acetone. The reaction has also been extended to encompass the synthesis of the more complex 2-(3-hydroxy-propyl)-3-(4-fluorophenyl)-1-methyl-4(1H)-quinolinone (10).     

Synthese von 1, 3, 4-Oxadiazolen und 4, 5-Dihydro-1, 2, 4-triazinen aus 3-Dimethylamino-2, 2-dimethyl-2 H-azirin und Carbohydraziden

Synthesis of 1,3,4-Oxadiazoles and 4,5-Dihydro-l,2,4-triazines from 3-Dimethylamino-2,2-dimethyl-2 Hazirine and Carbohydrazides 3-Dimethylamino-2, 2-dimethyl-2 H-azirine ( 1 ) reacts with aromatic carbohydrazides to give 2-(1-amino-1-methylethyl)-5-aryl-1, 3, 4-oxadiazoles ( 7 , 10 , 11 ). With ethyl carbazate the azirine 1 forms the aminoester 15 , which is easily cyclized to the 4, 5-dihydro-1, 2, 4-triazin-3 (2H)-one 16 . From the reaction of 1 with oxamohydrazide ( 17 ) and oxalodihydrazide 19 the 4, 5-dihydro-1, 2, 4-triazin-3-carboxamide 18 and the symmetric compound 20 , respectively, have been isolated. Reactions supporting the structures of the new compounds are described.     

A New Method of Cyclodehydration of 3,3-Dialkyl-1-Oxo-1-(2- hydroxyaryl)propan-3-ols to 2,2-Dialkyl-4-chromanones: Synthesis of Cannabinoid Synthon

A new method for cyclodehydration of o-hydroxyaryl-β-ketols to 4-chromanones using HMPT is described. The method has general applicability. It is particularly useful for the cyclisation of labile intermediates as exemplified by the synthesis of cannabinoid synthon, 2-methyl-2-(4-methyl-3-pentenyl)-7-methoxy-4-chromanone.