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1.
A series of seven new 2′,3′,4′‐substituted spiro[isothiochromene‐3,5′‐isoxazolidin]‐4(1H)‐ones ( 7‐13 ) has been prepared in the reaction of benzylidene(phenyl)azane oxide ( 5 ) or benzylidene(methyl)azane oxide ( 6 ) with (3Z)‐3‐(4‐substituted‐benzylidene)‐1H‐isothio‐ chromen‐4(3H)‐one ( 1‐4 ). The reaction occurs by a 1,3‐dipolar cycloaddition mechanism that leads to the regiospecific formation of various spiroisoxazolidines ( 7‐13 ).  相似文献   

2.
2(1‐Acetyl‐2‐oxopropylidene)naphtho[2,3‐d][1,3]dithiole‐4,9‐dione 1 reacts with a variety of bidentates reagents to give some new functionally substituted spiro naphthodithiole‐4,9‐dione derivatives.  相似文献   

3.
3,5‐Disubstituted Δ2‐isoxazolines can be prepared using the palladium‐mediated nucleometalation / methoxycarbonylation of β,γ‐unsaturated oximes. This novel route to this class of compounds is tolerant of a wide variety of functionality in the starting material, and provides a rapid route to highly functionalized isoxazolines.  相似文献   

4.
A series of some new spiro‐1,4‐dihydropyridine derivatives have been synthesized in good yields in a four component, and solvent‐free process by condensation of isatins, primary amines, ethyl cyanoacetate and cyclohexanone on solid support montmorillonite K10  相似文献   

5.
Tricyclic dihydropyridines like ZM244085 are potential KATP channel openers. In this study 3‐cyanophenyl ring of ZM244085 was replaced with imidazolyl ring. So, 9‐[1‐benzyl‐5‐(alkylsulfonyl)‐1H‐2‐imidazolyl]perhydro‐1,8‐acridinediones ( 5d‐f ) were synthesized from 2‐alkylsulfonyl‐1‐benzyl‐5‐formylimidazole ( 4d‐f ) and cyclohexane‐1,3‐dione according to classical Hantzch synthesis as potential potassium channel modulators.  相似文献   

6.
Compound 1 as a key intermediate for the synthesis of 3,3,7,7‐tetrakis‐(difluoroamino)octahydro‐1,5‐dinitro‐1,5‐diazocine (HNFX) and 3,3‐bis(difluoroamino)octahydro‐1,5,7,7‐tetranitro‐1,5‐diazocine (TNFX) is described. Cycloalkylation of 3 with 1,3‐dibromopropan‐2‐ol ( 4 ) afforded 1,5‐protected‐1,5‐diazocine 2 , followed by chromic acid oxidation to ketone 1 in good yield.  相似文献   

7.
A one pot synthetic approach to the novel [1,2,3]‐triazoles system, by 1,3‐dipolar cycloaddition of 2‐diazopropane to the imidates 2 , is described. The structures of the obtained adducts have been assigned by means of spectroscopic measurements.  相似文献   

8.
New and novel sulfone linked bis heterocycles_ bis pyrroles and pyrrolyl pyrazolines are prepared from 1‐arylsulfonyl‐2‐styrylsulfonylethenes by 1,3‐dipolar cycloaddition methodology.  相似文献   

9.
A novel versatile one‐pot oxidative deformylation approach has been developed to synthesize 4‐chloro‐2‐phenylquinolines and 4‐chloro‐2‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)quinolines from the corresponding N‐formyldihydroquinolines.  相似文献   

10.
A number of substituted 4H,5H,6H‐thiazolo[3,2‐a][1,5]benzodiazepinium salts 2a‐h, 5, 9 , which are based on the novel thiazolobenzodiazepine system, were prepared by condensation‐cyclization of 1,5‐benzodiazepine‐2‐thiones 1a‐f, h, 4 with α‐haloketones, as well as with α‐bromoacetaldehyde diethyl acetal. The structure and stereochemistry of the ring system obtained were investigated by 1H and 13C nmr spectroscopy: the additional heterocyclic nucleus was found to appreciably influence the conformational mobility of the heptatomic ring. Upon treatment of salt 2d with alkali the presence of the base enamine structure in solution has been postulated.  相似文献   

11.
Two competitive processes ‐ 1,3‐dipolar cycloaddition and nucleophilic addition ‐ in the reaction of 4,4,5,5‐tetramethyl‐4,5‐dihydro‐1H‐imidazole 3‐oxides with asymmetrically substituted alkynes were shown to occur. The influence of solvents and the nature of substituents in the reagent and substrate molecules on the rate ratio of these competitive processes were studied.  相似文献   

12.
A series of novel dispiro[oxindole‐thiazolidinedione]pyrrolidine, dispiro[oxindole‐thioxothiazolidinone]‐pyrrolidine, dispiro[oxindole‐dihydro‐pyrazolone]pyrrolidine were synthesized by both regio‐ and stereo‐selective 1,3‐dipolar cycloaddition reaction of azomethine ylide generated from amino acid and amino acid ester with π‐deficient alkenes in a single pot protocol in good yield. X‐ ray crystallographic studies established orthogonal disposition between spiro‐oxindole and spiro‐thiazolidinedione rings in 4a and 5a .  相似文献   

13.
Cyclocondensation of 2‐acylphenylacetonitriles 1 with amines affords 1‐substituted 3‐aminoisoquinolines 2 in good yields.  相似文献   

14.
The one‐pot two‐step synthesis for acyliminothiazolines by treatment of N,N'‐substituted thioureas with α‐bromocarbonyl compounds under aqueous media was described. Compared to classical reaction in organic solvents, this method consistently has the advantages of short reaction time and being environmentally friendly.  相似文献   

15.
3‐Amino‐3‐phenyl‐2‐phenylazoacrylonitrile 6 is obtained in good yield via reaction of 5 with phenyl magnesium bromide. The compound 6 is readily converted into 4a . The so formed alkanenitrile reacted with phenylmagnesium bromide to yield 8 . Compound 8 could be also obtained from reaction of 9 with phenylmagnesium bromide. The arylhydrazononitriles 8 and 4a reacted with chloroacetonitrile to yield the 4‐aminopyrazoles 12a,b . Compound 12a reacted with acetic anhydride to yield the 15a and with benzoyl chloride to yield the pyrazole 16 which was converted into 15b . Refluxing 10 in acetic acid gave a mixture of the azadiene 21 and the cinnoline 22 is obtained. The azadiene 21 is converted into 22 either thermally or photochemically.  相似文献   

16.
Novel microwave induced method for the synthesis of thiazolidine‐2,4‐dione motif under solvent phase conditions is developed. Further we report an efficient, microwave assisted method for the parallel syntheses of biologically important 5‐benzylidene‐thiazolidine‐2,4‐dione and 5‐benzylidene‐2‐thioxothiazolidine‐4‐one compounds under solid‐phase and solvent‐free conditions. A comparative study between the developed microwave methods and the conventional methods is described. We have also illustrated the possible mechanism behind to address the reason why piperidine, acetic acid and silica gel enhanced the Knoevenagel condensation reaction.  相似文献   

17.
The parent compound 5‐oxo‐10a‐phenyl‐2,3,10,10a‐tetrahydro‐5H‐[1,3]‐oxazolo‐[3,2‐b]‐isoquinoline‐10‐carboxylic acid ( 5 ) was prepared in large scale and a good yield by reaction between homophthalic anhydride ( 3 ) and 4,5‐dihydro‐2‐phenyl‐1,3‐oxazole ( 4 ). Thus, the closure of the isoquinoline ring and fusion of the 1,3‐oxazol ring occur in one step. Trans configuration was assumed for the product. The parent acid 5 was converted in four steps to the target aminomethyl derivatives 9a‐1 . The latter contain four features that make them interesting from pharmaceutical point of view.  相似文献   

18.
A series of 2‐acyl‐2H‐1,2,3‐diazaphospholes 3 underwent ready 1,3‐dipolar cycloaddition reactions with 9‐diazofluorenes as the 1,3‐dipole, yielding the respective bicyclic phosphiranes 5 or trimers 7 depending on the reaction conditions employed. The reaction is believed to proceed via the formation of the [3+2]‐cycloaddition adducts followed by elimination of nitrogen from the cyclic azo moiety. In the case of 3c , the phosphatetraazabicyclooctadiene compound 6 has been isolated with no loss of nitrogen. Likewise, the dipolar cycloaddition reaction of diphenyldiazomethane with the >C?P‐ moiety as the 1,3‐dipolarophile gave phosphadiazabicyclohexenes 8 in 32–68% yields.  相似文献   

19.
Reaction of 2‐(5‐substituted‐2‐hydroxybenzylamino)phenols ( 2 ) with formalin in ethanol under reflux has chemoselectively led to 2‐(6‐substituted‐2H—benzo[e][1,3]oxazin‐3(4H)‐yl)phenols ( 3 ) in good yield involving the ring closure of the hydroxyl group of the C‐aryl ring and not that of the N‐aryl ring.  相似文献   

20.
Dilithiated 1‐tetralone oxime was condensed with several electron enriched aromatic aldehydes, such as 4‐methoxybenzaldehyde or lithiated 4‐hydroxybenzaldehyde, followed by acid cyclization to new tetrahydronaphthisoxazoles, 3,3a,4,5‐tetrahydronaphth[1,2‐c]isoxazoles, with a trans geometry of the C3‐H and C3a‐H protons that was confirmed by X‐ray single crystal analysis.  相似文献   

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