New heterocyclic ring systems from α-hydroxymethyleneketones. X Thiadiazasteroid-related compounds

Some thiadiazasteroid analogues have been synthesized by the reaction of 3-hydroxymethyl-enebenzo[h]thiochroman-4-one with hydrazine and substituted hydrazines, semicarbazide and thiosemicarbazide. Pmr data supporting the structural assignments have been discussed.     

Synthesis of 1-tetralones by intramolecular Friedel-Crafts reaction of 4-arylbutyric acids using Lewis acid catalysts

Intramolecular Friedel-Crafts reaction of 4-arylbutyric acids efficiently proceeded in the presence of catalytic amounts of Lewis acids such as Bi(NTf₂)₃ and M(OTf)₃ (M=Bi, Ga, In and rare-earth metals) to form 1-tetralones. Chroman-4-one and thiochroman-4-one were also obtained in good yields from 3-phenoxypropionic acid and 3-phenylthiopropionic acid, respectively.     

A FACIAL SYNTHESIS OF THE NEUTRAL [1,2,4]TRIAZOLO- [3,2-d][1,5]BENZOXAZEPINES AND THEIR CHALCOGEN-ANALOGUES

ABSTRACT

An expedient synthesis of neutral [1,2,4]triazolo[3,2-d][1,5]-benzoxazepines 6a–e and their chalcogen analogues 6f–i was accomplished via cycloaddition of the heterocumulene cations (3a,b), generated sequentially by action of chroman-4-one as well as thiochroman-4-one ethoxy carbonylhydrazones (1a,b) with t-BuOCl and SbCl₅, to the triple bond of nitriles and concurring ring enlargement and hydrolytic removal of the N(1)-ethoxycarbonyl group. The oily final products were characterized as their picrates.     

4-溴-2-环戊烯砜酯化衍生物的合成

以3,4-二溴环戊砜(1)为原料, 在无水吡啶作用下发生消除反应, 得到反应中间体4-溴-2-环戊烯砜(2), 再分别与一系列取代苯甲酸盐3a～3c以及茜素黄GG (3d)发生酯化反应, 合成出4种新环戊烯砜衍生物4a～4d, 并用IR, ¹H NMR, MS, 元素分析等表征了它们的结构.     

Fluorination with xenon difluoride; Part IX. Reaction with phenylsubstituted sulphides

Fluorination of phenyl-methylsulphide with xenon difluoride yields phenyl-fluoromethylsulphide. Further fluorination leads to phenyl-difluoromethylsulphide. Reaction with cis-2,6-diphenyltetrahydro-1-thio-4-pyrone results in the dehydrogenated product 2,6-diphenyldihydro-1-thio-4-pyrone, while further reaction leads to 2,6-diphenyl-1-thio-4-pyrone; thiochroman-4-one yields thiochromen-4-one. No evidence for precursors of the products isolated at room temperature was found.     

Synthesis of 6-methoxy-2,2-dimethyl-2H-1-benzothiopyran and 6,7-dimethoxy-2,2-dimethyl-2H-1-benzothiopyran,sulfur analogues of precocene I and precocene II

Preparation of title compounds 5 , sulfur analogues of the natural insect antijuvenile hormones precocene I and II, is described. The synthetic pathway involves conversion of the appropriate thiophenol 2 into the corresponding thiochroman-4-one 4 followed by reduction and dehydration. The ¹³C nmr data for all the above products are also reported.     

Synthesis and antiemetic activity of 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives

5-HT₃ receptor antagonists, such as Ondansetron, are used for anti-emesis after chemotherapy, radiotherapy and operations. Some Ondansetron analogs possessing piperazine ring as side chains were synthesized in our lab. Thus, one of the two carbonyl groups of starting material 1,3-cyclohexandione (1) was condensed with phenylhydrazine hydrochloride to form monophenylhydrazone (2). 1,2,3,9-Tetrahydro-4H-carbazol-4-one (3) was prepared from 2 via cyclization and rearranged in the presence of ZnCl₂. Through a methylation reaction, compound 3 was converted to 1,2,3,9-tetrahydro-9-methyl-4H-carbazol-4-one (4). 3-Dimethylaminomethyl substituted compound (5) was synthesized from 4 by a Mannich reaction in glacial acetic acid. Nine novel 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-1-ylmethyl)-4H-carbazol-4-one derivatives (6a–6i) were synthesized through nucleophilic substitution reaction of 5 with piperazines. The structures of all the target compounds were determined by elemental analysis, IR, MS, ¹H NMR and ¹³C NMR spectra. The results of preliminary pharmacological test show that part of the novel compounds have antiemetic activity comparable to that of the control Ondansetron. __________ Translated from Chinese Journal of Organic Chemistry, 2008, 28(2) (in Chinese)     

N,S-, S-, S,S-, <S═O-, and < SO2-Substituted Dienes from Halo-1,3-Butadienes

Mono(thio)substituted dienes 1 gave 3a–g , 5 , and 7 with piperazine derivatives in dichloromethane. Hexachlorobutadiene 14 in a water-ethanol mixture in the presence of sodium hydroxide reacted with thiol 15 to give the mono(thio)substituted thioether 16 and di(thio)substituted thioether 17 . 18 was obtained from the reaction of 16 with m-CPBA in chloroform. 9 was obtained from the reaction of l,2,3,4,4-pentachloro-(1-2-hydroxyethylthio)-1,3- butadiene 8 with 47% HI, and 11 was synthesized from the reaction of 8 with concentrated H₂SO₄ and KBr. Compounds 9 and 11 gave in the reaction with m-CPBA in chloroform 10 , 12 , and 13 , respectively.     

Reaction of aspartic acid derivatives with Grignard reagents—synthesis of γ,γ-disubstituted α- and β-amino-butyrolactones

A series of γ,γ-dimethyl and γ,γ-diphenyl substituted α- and β-amino-butyrolactones have been prepared in enantiomerically pure form using l-aspartic acid as a chiral building block. For the final Grignard reaction the difference in chemical reactivity between the carboxyl groups of aspartic acid was increased or inverted by preparing the corresponding semiesters, diesters and anhydrides. The resulting hydroxyacids and hydroxyesters lactonised in most cases during work up. Thus, (2S)-2-ethoxycarbonylamino-succinic acid-4-methylester 1 reacted with methylmagnesium iodide to form (3S)-3-ethoxycarbonylamino-5,5-dimethyl-tetrahydrofuran-2-one 2b. Two interesting side products were obtained and were found to result from attack at the C-1 carboxylic acid rather than the C-4 carboxylic ester group leading to (3S)-3-ethoxycarbonylamino-4-oxo-pentanoic acid methylester 3 and (4S)-4-ethoxycarbonylamino-5,5-dimethyl-tetrahydrofuran-2-one 5a.     

New N,S-Substituted Dienes from Mono(thio)substituted-2-nitrohalo-1,3-diene and Some Amines

Mono(thio)substituted nitrodiene compound 1 reacted with 2a–f and yielded 3a–f in methylene chloride. Compound 1 gave 7 by the reaction with 6. Compounds 5a–c were obtained by the reactions of 4a–c with 1. 3a also has been structurally characterized using single-crystal X-ray diffraction analyses.     

Ecofriendly and highly efficient microwave-induced synthesis of novel quinazolinone-undecyl hybrids with in vitro antitumor activity

Abstract

Novel N-alkyl-quinazolin-4-one derivatives 3–5 were obtained from reaction of 6-Iodo-2-undecylquinazolin-4(3H)-one (2) with different alkyl halides. Hydrazinolysis of compound 5 gave the acetohydrazide 6 which reacted with different carbon electrophiles to produce 2-undecyl-4(3H)-quinazolinone derivatives. The new products were obtained by either conventional method or by microwave assisting technique and the structure of all products was confirmed by elemental and spectral data. The ecofriendly microwave provides an efficiency over than conventional method in many aspects. All the synthesized products were tested in vitro against a panel of three human tumor cell lines, namely, hepatocellular carcinoma (liver) HepG2, colon cancer HCT-116, and mammary gland breast MCF-7. Almost all of the tested compounds showed satisfactory activity.     

3-(4-取代-哌嗪-1-甲基)-1,2,3,9-四氢咔唑-4-酮衍生物的合成与止吐活性研究

以1,3-环己二酮(1)为起始原料, 一个羰基与盐酸苯肼发生缩合反应生成1,3-环己二酮单苯腙(2), 2在ZnCl₂催化下通过分子内环合、重排反应得到1,2,3,9-四氢咔唑-4-酮(3), 3的甲基化物4在冰醋酸中经Mannich反应获得其3-二甲胺甲基物5, 5与哌嗪类化合物通过亲核取代反应合成了9个未见文献报道的3-(4-取代-哌嗪-1-甲基)-1,2,3,9-四氢咔唑-4-酮衍生物6a～6i. 所有合成的新化合物均经元素分析、红外光谱、质谱和核磁共振光谱证明其结构; 初步药理试验采用顺铂诱导的大鼠干呕模型研究了新化合物的止吐活性, 结果表明部分新化合物活性与昂丹司琼相当.     

Synthesis and Reactions of Polynuclear Heterocycles: Azolothienopyrimidines and Thienothiazolopyrimidines

We prepared a thieno[2,3-d]pyrimidine compound fused with a thiazolo ring to produce biologicaly active compounds. In a one-step reaction, 2-arylmethylene derivative (3) was prepared via the reaction of a ternary mixture of 2-thioxo-1,2,3,4-tetrahydrocyclohepteno[4,5]thieno[2,3-d]pyrimi-dine-4-one (2), cloroacetic acid, and a proper aldehyde. The reaction of 2 with 3-chloropent-2,4-dione in ethanolic potassium hydroxide yielded the S-acetylacetone derivative 4e. The latter compound reacted with hydrazine hydrate and phenyl hydrazine to give 2-pyrazolthio derivatives 8a,b, respectively. Compound 4e also underwent cyclization on boiling with acetic anhydride/pyridine solution to form 2-acetyl-3-methyl thiazolo[3,2-a]cyclohepteno[4,5]thieno[2,3-d] pyrimidine-5-one (9). To support the structure 9, it gave a characteristic reaction for the 2-acetyl group. The 2-methylthio derivatives 4a underwent further alkylation at N₃ to give 6a,b. The purpose of the synthesis of thienopyrimidine derivatives is due to high biological activities. The 4-oxo-thienopyrimidine derivatives acted as inhibitors of adenosine kinase, platelet aggregation, antilukemia, and anticancer activities.     

Einige Neue N,S-Substituierte 2-Nitrodienverbindungen Aus Reaktionen Von Mono(p-fluorarylthio)substituierten Dienen Mit Aminen

2-Nitrodiene compound 1 was stirred with p-fluorothiophenol for a long time and compound 3 was obtained. Compound 1 gave bis(thio)substituted 2-nitrodiene compound 4 and tris(thio)substituted compound 5 with 2 moles of p-fluorothiophenol in the presence of NaOH in ethanol. The compounds 9a–g have been prepared from 8a–g and 3. Compound 7 was obtained from the reaction of mono(thio)substituted 2-nitrodiene with morpholine. Compound 3 gives 11a–d in the reaction with piperidines in CH₂Cl₂ (or ether). Compound 13a–b have been obtained from the reaction of compound 3 with primary amines 12a–b. Compound 3 gives 15 and 16 in the reaction with 2,5-dimethylpiperazine in CH₂Cl₂.

     

Synthesis of Some Novel 5-(Arylidene)-2-imino-3(pyridin-2-yl)thiazolidin-4-one Derivatives

Treatment of 2-aminopyridine ( 1 ) with chloroacetyl chloride in dry benzene gave 2-chloro-N-(pyridin-2-yl)acetamide ( 3 ), which on further reaction with potassium thiocyanate gave 2-imino-3-(pyridin-2-yl)thiazolidin-4-one ( 4 ) as an intermediate compound for the synthesis of pyridin-2-yl substituted 2-imino-thiazolidine-4-one derivatives. Cyclocondensation reaction of ( 4 ) with a series of aromatic aldehydes gave 5-arylidene derivatives of pyridin-2-yl substituted 2-imino-thiazolidine-4-ones 5a–j . ¹ H and ¹³C NMR spectroscopy, as well as elemental analyses, were used for the identification of these new compounds.     

The Reaction of 1-Aryl-2-(4-nitrophenylsulfonyl)ethanones with α,β-Unsaturated Esters

1-Aryl-2-(4-nitrophenylsulfonyl)ethanones (1) reacted with one equiv. of α,β-unsaturated esters at 60°C to afford the tandem addition-rearrangement products (3), while at 75°C 1a reacted with two equiv. of methyl acrylate and gave an unexpected addition-rearrangement-addition-annulation product which is dimethyl 4-hydroxyl-1-(4-nitrophenyl)-4-phenyl-1,3-cyclohexyldicarboxylate (4). A mechanism is suggested.     

Studies on Organophosphorus Compounds XI: The Reaction of Phosphorus Reagents With Hydrazonoyl Halides,Hydrazonoyl Azides,and Shiff's Bases

N-(chloro-furan-2-yl)methylene-N′-(4-nitrophenyl)hydrazone (I) reacted with triethylphosphite to produce the phosphonate derivative III. The tetrazine derivative VI was produced by the interaction of I with diethyl-phosphite. Hydrazonoyl azide derivatives VIIIa–c reacted with triphenyl phosphine to form the iminophosphorane derivatives Xa–c. On the other hand, the azide derivative VIIIc reacted with the phosphonium ylide XI to form the 1,2,3-triazole adduct XIII. The reaction of triethyl phosphite with Shiff's bases XIVa–c yielded the corresponding phosphonates XVa–c. The structures of the newly prepared compounds were confirmed with the analytical and spectroscopic evidences.     

Regio- and stereoselective synthesis of bis-spiropyrazoline-5,3′-chroman(thiochroman)-4-one derivatives via bis-nitrilimines

Regioselective 1,3-dipolar cycloaddition of the bis-nitrilimines with the benzylidene derivatives of chroman-4-one and thiochroman-4-one afforded the corresponding bis-spiropyrazoline derivatives. X-ray analysis was used in the elucidation of the regio- and stereochemistry of the products. Similar reactions of the bis-nitrilimines with 2-benzylidene-3-coumaranone furnished 3,3′-bipyrazole derivatives.     

Diels-alder reactions with ethyl 1-benzofuran-3-carboxylates

Substituted salicylaldehydes reacted with ethyl diazoacetate to give ethyl 1-benzofuran-3-carboxylates containing various substituents in the aromatic ring. The Diels-Alder reaction of these compounds with Danishefsky’s diene was regioselective, and it provided an effective method for the construction of the heterocyclic skeleton of hexahydrodibenzo[b,d]furan-7-one or tetrahydrodibenzo[b,d]furan-7-one. The adducts were found to undergo rearrangement to substituted 4′-hydroxybiphenyl-2-yl methyl carbonates during column chromatography on silica gel.     

Heterocyclic ketones in the pfitzinger reaction

By the reaction of isatin with heterocyclic ketones (N-tert-butoxycarbonyl derivatives of pyrrolidin-3-one, piperidin-4-one, piperidin-3-one, 1,2,3,4-tetrahydroquinolin-4-one, 8-azabicyclo[3.2.1]octan-3-one, tetrahydropyran-4-one, tetrahydrobenzopyran-4-one) in the presence of KOH (the Pfitzinger reaction) were synthesized quinoline-4-carboxylic acids [4,3]fused with the respective heterocycles. These acids were involved in the reactions with diazomethane and amines at the carboxy group leading to methyl esters and amides, respectively. The esters obtained reacted with hydrazine hydrate affording the acid hydrazides, which entered in the condensation with benzaldehyde to form phenylhydrazones. The esters and amides containing N-tert-butoxycarbonyl fragment lost the tert-butoxycarbonyl group easily to form the secondary amines dihydrochlorides, the [4,3]fused quinoline-4-carboxylic acid derivatives.