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1.
Syntheses of 11-acety1-2-phenylpyrimido[5,4-c][1,5]benzoxazepin-5(11H)one ( 16a ) and analogs ( 16b,c, 22 ) were described. The reaction of 4-chloro-2-phenyl-5-pyrimidinecarboxylic acid ethyl ester ( 7 ) with 2-aminophenol afforded 4-(2-hydroxyanilino)-2-phenyl-5-pyrimidine-carboxylic acid ethyl ester ( 8a ). The latter was also prepared by catalytic reduction of 4-(2-nitrophenoxy)-2-phenyl-5-pyrimidinecarboxylic acid ethyl ester ( 9 ), which was obtained from 7 and 2-nitrophenol. Involvement of 4-(2-aminophenoxy)-2-phenyl-5-pyrimidinecarboxylic acid ethyl ester ( 12a ) in this reduction as an intermediate was demonstrated by an independent synthesis of 12a and its subsequent rearrangement to 8a. Hydrolysis of 8a or 12a gave 4-(2-hydroxyanilino)-2-phenyl-5-pyrimidinecarboxylic acid ( 15a ). Reaction of 15a with acetic anhydride afforded 16a , the first member of a novel ring system, the pyrimido[5,4- c ][1,5]-benzoxazepin. Additional examples ( 16b,c ) were prepared similarly. The corresponding 11-ethyl derivative ( 22 ) was prepared in similar fashion, starting with 7 and 2-ethylaminophenol. A possible reaction mechanism for the formation of 16a-c from 15a-c and acetic anhydride was discussed.  相似文献   

2.
Reaction of 2-(3-,4-)pyridinecarboxaldehydes 5 with carbomethoxymethylene triphenylphosphorane afforded predominantly E-methyl-3-(pyridinyl)-2-propenoates 7. Oxidation of 7a-c with m-chloroperbenzoic acid gave methyl E-3-(1-oxidopyridinyl)-2-propenoates 8a-c in high yield. The Darzen's reaction of 5a-c with methyl bromoacetate yielded a mixture of stereoisomers cis- 9a-c and methyl trans-3-(pyridinyl)-2,3-epoxy-propanoates 10a-c in a ratio of 2:1. Oxidation of cis- 9a-c and trans- 10a-c afforded the corresponding cis- 11a-c and methyl trans-3-(1-oxidopyridinyl)-2,3-epoxypropanoates 12a-c in good yield. The reaction of 11a and 12a with cyclic amines as piperidine gave the respective threo- 13 and methyl erythro-2-(1-piperidino)-3-hydroxy-3-(1-oxido-2-pyridino)propanoate 14. The sodium borohydride reduction of the N-alkoxylcarbonyl pyridinium salts of 9c and 10c afforded the corresponding N-alkoxycarbonyl-1,2-dihydropyridyl derivatives 15 and 16. A number of selected compounds ( 7a-c , 9a-c , 10a , 10c , 11a-c and 12a , 12c ) were found to be inactive in the P388 Lymphocytic screen. Compounds 9-12 did not react with the model nucleophile ethanethiol in phosphate buffer at 37°.  相似文献   

3.
The synthesis of an array of P-chiral amino acid-derived phosphonamidic anhydrides is described. These anhydrides are prepared by condensation of allylated amino acids 19-22 with methyl- or vinylphosphonic dichlorides 23 or 24 to produce three diastereomeric anhydrides 4-11a-c in good to excellent yields. The mechanistic issues concerning anhydride formation are discussed and supported by experimental results. Vinylphosphonamidic anhydrides 8-11 are further derivatized via the ring-closing metathesis (RCM) reaction to yield amino acid-derived bicyclic phosphonamidic anhydrides.  相似文献   

4.
Synthesis of novel 4,9-methanoundecafulvene [5-(4,9-methanocycloundeca-2',4',6',8',10'-pentaenylidene)pyrimidine-2(1H),4(3H),6(5H)-trione] derivatives 10a-c was accomplished. Their structural characteristics were investigated on the basis of the 1H and 13C NMR and UV-vis spectra. Upon treatment with DDQ, 10a-c underwent oxidative cyclization to give novel 11,13-disubstituted 3,8-methanocycloundeca[8,9-b]pyrimido[5,4-d]furan-12(11H),14(13H)-dionylium tetrafluoroborates 11a-c*BF4- in good yields. The spectroscopic properties of 11a-c*BF4- were studied, and the structural characterization of 11b*BF4- was performed by the X-ray crystal analysis. Cations 11a-c were very stable, and their pKR+ values were determined spectrophotometrically to be 8.3-8.9. The electrochemical reduction of 11a-c exhibited low reduction potentials at -0.43 to -0.45 (V vs Ag/AgNO3) upon cyclic voltammetry (CV). In a search for reactivity, reactions of 11a*BF4- with some nucleophiles, hydride and diethylamine, were carried out to clarify that the methano-bridge controls the nucleophilic attacks to occur with endo-selectivity. The photoinduced oxidation reactions of 11a*BF4- toward some amines under aerobic conditions were carried out to give the corresponding carbonyl compounds in more than 100% yield.  相似文献   

5.
The synthesis of a range of highly constrained cyclic tripeptides has been performed using either an intramolecular Sonogashira coupling or a macrolactamization as the final ring-closing reaction. Our approach gives access to rigidified 15-membered peptidic macrocycles based on the central ring system of vancomycin. Tripeptides 3a-c and dipeptide 11 were cyclized via an intramolecular Sonogashira reaction, and the cyclic peptides 4a-c and 15a were obtained in 6-23% yield. In contrast, macrolactamization of 12 and 17 resulted in the desired peptidic macrocycles 15b and 18 with 54-61% yield. Modeling studies hint at a distorted triple bond, which explains the low yield of the Sonogashira-based cyclization. Moreover, modeling data also showed that this class of peptidic macrocycles formed a cavity-like structure in which guest molecules may bind.  相似文献   

6.
The synthesis of 8-substituted and unsubstituted 6H,11H-indolo[3,2-c]isoquinolin-5-ones/thiones 3a-c and 4a-c and their derivatives viz, ethyl (8-substituted-6H,11H-indolo[3,2-c]isoquinolin-5-on-6-yl)acetates 5a-c , (8-substituted-6H,11H-indolo[3,2-c]isoquinolin-5-on-6-yl)acetyl hydrazides 6a-c , 3,5-disubstituted-pyrazoles 7a-c and 8a-c , 3-substituted-pyrazol-5-ones 9a-c and 5-(8-substituted-6H,11H-indolo[3,2-c]isoquinolin-5-on-6-yl)methyl-1,3,4-oxadiazole-2-thiones 10a-c , also ethyl (8-substituted-11H-indolo[3,2-c]isoquinolin-5-ylthio)ace-tates 11a-c , (8-substituted-11Hindolo[3,2-c]isoquinolin-5-ylthio)acetyl hydrazides 12a-c , 3,5-disubstituted-pyrazoles 13a-c and 14a-c , 3-substituted-pyrazol-5-ones 15a-c and 5-(8-substituted-11H-indolo[3,2-c]isoquin-olin-5-yl)thiomethyl-1,3,4-oxadiazole-2-thiones 16a-c is described.  相似文献   

7.
Reactions of N,N;-disubstituted hydrazinecarbothioamides 8a-c and substituted thioureidoethylthioureas 9a-c with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil, 10a) and 2,3,5,6-tetrabromo-1,4-benzoquinone (bromanil, 10b) to form N,N;-disubstituted [1,3,4]thiadiazole-2,5-diamines 11a-c, 6,7-dichloro-3-substituted amino-1H-benzo[1,3,4]- thiadiazine-5,8-diones 12a-c, 2,3,7,8-tetrahalothianthrene-1,4,6,9-tetraones 13a,b, 5,6,8- trihalo-7-oxo-3,7-dihydro-2H-quinoxaline-1-carbothioic acid substituted amides 14a-c, 15a-c and 7-substituted imino-[1,3,6]thiadiazepane-3-thiones 16a-c are reported. Rationales for the observed conversions are presented.  相似文献   

8.
A new versatile synthesis strategy for macromonomers has been developed that uses the living ring‐opening metathesis polymerization (ROMP) with commercial Grubbs first generation ruthenium initiators. Homopolymers as well as diblock copolymers were end‐functionalized with norbornene derivatives to serve as macromonomers. The graft copolymerization of the macromonomers was also carried out employing ROMP. Well‐defined and highly functional graft copolymers are accessible by this new synthetic route.

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9.
Kinetic vs thermodynamic deprotonation studies on secondary and tertiary sulfonamides 1 and 2 using n-BuLi have been carried out. While both 1 and 2 show kinetic ortho-metalation, thermodynamic conditions lead to ortho and benzylic deprotonation, respectively (Figures 1 and 2). Metalation of 1 using the n-BuLi/KOtBu superbase led to regioselective benzylic metalation (Figure 4); LDA deprotonation was also briefly explored. Application of the developed conditions allows the synthesis of diverse sulfonamide products 5a-e, 6a-e, 7a,b, and 8a-e. Ipso-bromo desilylation reactions afford sulfonamides 9a,b while Suzuki cross-coupling reactions furnish biaryl sulfonamides 11a-c.  相似文献   

10.
The tandem Diels-Alder/dehydrochlorination reaction of semisquaric chloride (1) with the 1,2-bis(methylene)cycloalkanes 2a-c and 1,2-bis(methylene)-4-cyclohexene (9) affords the linearly-fused cycloalkanodihydrobenzocyclobutene-1,2-diones 3a-c and 3,4,7,8-tetrahydrocyclobuta[b]-naphthalene-1,2-dione (10), respectively. On treatment with MnO2, 3a-c are dehydrogenated to the respective carbocycle-fused benzocyclobutene-1,2-diones 4a-c in good yields. 3a and 3b react with bromine to give the addition products 5a,b, which, on treatment with silver trifluoroacetate, afford the benzocyclobutene-1,2-diones 4a,b. For preparative purposes, the sequence 3-->5-->4 can be performed advantageously as a "one-pot procedure". Double-condensation reactions of 4a,b with alpha,alpha'-biscyano-o-xylene and o-phenylenediamine afford the pentacyclic biphenylenes 7a,b and the cyclobutahetarenes 8a,b, respectively. These cyclobutenediones suggest themselves as building blocks for the construction of extended linearly-fused polycyclic compounds with novel ring sequences. o-Quinodimethanes 12a-g generated in situ by the thermal decomposition of the respective 1,4-dihydro-2,3-benzoxathiin-3-oxides (sultines) 11a-g react with semisquaric chloride (1) to afford the 3,8-dihydronaphtho[b]cyclobutene-1,2-diones 13a-g. These, on dehydrogenation with bromine and/or MnO2, furnish the naphtho[b]cyclobutene-1,2-diones 14a-g in fair to good yields. As described for 4a,b the naphtho[b]cyclobutene-1,2-diones 14a-c are condensed with alpha,alpha'-biscyano-o-xylene and o-phenylenediamine to furnish the pentacyclic biphenylenes 15a-c and the pentacyclic cyclobutahetarenes 16a-c.  相似文献   

11.
1:1 cyclic compounds 8a-c (51-55%) and 2:2 cyclic compounds 9a-c (20-49%) containing 1,4,7,10-tetraazacyclododecane (cyclen) and azobenzene units were selectively synthesized under UV irradiation (330 nm < lambda < 380 nm) and in the dark. Synthesis depended on the wavelength of irradiation light and the length of methylene chains of the linker between the cyclen and azobenzene units. A study of NMR and UV-vis spectra indicated that properties of 8a-c and 9a-c are closely related to their structural flexibility. Rate constants (k) and thermodynamic parameters (DeltaG(), DeltaH(), and DeltaS()) of 8a-c and 9a-c were studied in nonpolar media (benzene) and polar media (methanol). The cis to trans isomerization rates in the dark for these cyclic compounds increase with ring size or structural flexibility (8a < 8c < 8b < 9a < 9b < 9c). In principle, DeltaS() dominates DeltaG() in cyclic compounds.  相似文献   

12.
The total synthesis of curvulone B was achieved, and its absolute configuration unambiguously established, as had been determined by TD-DFT ECD calculations on the computed solution conformers. Key features of the synthesis were an olefin cross-metathesis of an α,β-unsaturated ketone as a common key building block with (R)-6-triethylsilyloxyhept-1-ene, and an intramolecular oxy-Michael addition of the hydroxyl enone obtained therefrom. An intermolecular metathesis of the enone with (S)-5-benzyloxyhept-ene also enabled us to prepare a proposed structure for dothiorelone B, thus leading to the confirmation of the structural revision of phomopsin A, a novel nine-membered cyclic phenol ether.  相似文献   

13.
A total synthesis of the laurencia metabolite (+)-obtusenyne has been completed. The key steps include a Sharpless kinetic resolution and an asymmetric glycolate alkylation to establish the stereogenic centers adjacent to the ether linkage and a ring-closing metathesis reaction to construct the nine-membered ether without the aid of a cyclic conformational constraint. The synthesis was completed in 20 linear steps from commercially available 1,5-hexadiene-3-ol.  相似文献   

14.
Seven-membered cyclic compounds possessing trisubstituted double bonds have been effectively constructed employing the Grubbs catalyst to effect olefin metathesis. The keto ester does not undergo cyclization; however, alcohols protected by the silyl groups smoothly cyclized into seven-membered compounds. The product was successfully converted to (-)-13(15)E,16E-3beta,4beta-epoxy-18-hydroxysphenoloba-13(15),16-diene and (-)-13(15)Z,16E-3beta,4beta-epoxy-18-hydroxysphenoloba-13(15),16-diene, liverwort diterpenes isolated from Anastrophyllum auritum to establish the absolute configuration.  相似文献   

15.
The first enantioselective peroxidation of prochiral allylic and benzylic C-H compounds by the use of chiral bisoxazoline-copper(I) complexes, generated in situ from the ligands 3 and 4a-d, and t-BuOOH as oxidant is reported. Cyclohexene 1, cyclopentene 5, -angelica lactone 7, allylbenzene 9 and 2-phenylbutane 11 were converted into the optically active allylic and benzylic tert-butyl peroxides 2, 6, 8, 10a and 12 in good yields and ee values of 4-20%. Oxidations of 1-substituted 1-cyclohexenes 13a-c led to mixtures of regioisomeric peroxides 16a-c, 17a-c and 18a-c with different regio- and enantioselectivities, depending on the 1-substituent and the ligand used. The highest ee values (up to 84%) were observed for (S)-3-tert-butylperoxy-1-methyl-1-cyclohexene 17a.  相似文献   

16.
Through current and previous researches, it was found that the derivatives of pyridazine, isoxazole, tetrazole, quinazoline, hydrazinyl, and 1,2,4-triazole have many pharmacological activities. Thus, a series of novel furopyridazinones ( 7 ), isoxazolopyridazine ( 8 ), sub-benzylidene-furopyridazinones ( 9a-c ), isoxazolofuropyridazines ( 10a-c ), 3-chloro-(pyridin-4-ylmethylene)-dihydropyridazines ( 11 ), tetrazolopyridazines ( 12 ), pyridazinoquinazolinones ( 13 ), piperazinyl/morpholino-pyridazines ( 14a,b ), hydrazinyl-pyridazines ( 15 ), and 1,2,4-triazolo-pyridazines ( 16a,b ) in good yields (72%-90%) were synthesized from substituted ethyl 4-oxo-4-phenylbutanoate ( 2 ), 6-phenyl-4,5-dihydropyridazinone ( 3 ), and 6-phenyl-4-(pyridin-4-ylmethylene)-4,5-dihydropyridazinone ( 4 ) as beginning materials. All the chemical structures of the new compounds have been demonstrated by different spectroscopy analyses such as infrared, NMR, mass spectrum, and elemental analysis. Also, the activities of the newly prepared compounds were tested against many types of bacteria and fungi in vitro. Hence, 1,2,4-triazolopyridazines ( 16a,b ), isoxazolofuropyridazines ( 10a-c ), tetrazolopyridazines ( 12 ), Piperazinyl/morpholinyl-pyridazines ( 14a,b ) displayed the most efficient antimicrobial activities compared with the cefotaxime sodium and nystatin as standard drugs.  相似文献   

17.
A fluorous-tagged linker for the parallel synthesis of small- and medium-ring and macrocyclic nitrogen heterocycles using ring-closing metathesis is described. The linker was designed such that "cyclization-release" of the cyclic heterocyclic products was coupled with liberation of the active catalyst. The design of the linker was validated using a non-fluorous-tagged model. A wide range of unsaturated alcohols were used as reagents to functionalize a fluorous-tagged sulfonamide, (Z)-{N-[4-(2-(N'-3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)-4-methylsulfonamido)methylallyloxy]but-2-enyl}-2-nitrobenzenesulfonamide, using Fukuyama-Mitsunobu reactions; in each case, fluorous-solid-phase extraction (F-SPE) was used to purify the functionalized linker from the excess reagents. In general, the "cyclization-release" of cyclic products was triggered using a light-fluorous tagged derivative of the Grubbs-Hoveyda second-generation catalyst. After the metathesis step, F-SPE was used to purify released cyclic compounds from the fluorous-tagged linker and the fluorous-tagged catalyst. The scope and limitations of the approach were determined using a range of substrates which probed different aspects of the functionalization and metathesis steps. In the study as a whole, a wide range of small- and medium-ring and macrocyclic nitrogen heterocycles were prepared using polyene and polyenyne metathesis cascades.  相似文献   

18.
Intermolecular Diels-Alder reactions of masked o-benzoquinones, i.e., 6,6-dimethoxy-2,4-cyclohexadienones 5-7 and 21-24 generated from 2-methoxyphenols 1-3 and 17-20, respectively, with electron-deficient dienophiles leading to highly functionalized bicyclo[2.2.2]octenones are described. The masked o-benzoquinones (MOBs) 5-7 underwent Diels-Alder cycloadditions with methyl acrylate, methyl methacrylate, and methyl vinyl ketone to provide bicyclo[2.2.2]octenones 13a-c to 15a-c (direct method) in low to moderate yields with the concomitant formation of considerable amounts of dimers 9-11. To retard dimerization and to improve the yields of the requisite bicyclo[2.2.2]octenones, a detour method comprised of sequential bromination of 2-methoxyphenols 1-4, oxidation and Diels-Alder reaction, and debromination has been developed. The oxidation of bromophenols 17-20 produced MOBs 21-24 which are stable enough to be isolated. The MOBs 21-24 underwent cycloaddition with electron-deficient dienophiles in a very efficient manner to afford the corresponding cycloadducts 25a-c to 28a-c in good to high yields without self-dimerization. When the cycloadducts 25a-c to 28a-c were treated with either Bu(3)SnH/AIBN or tributylammonium formate-palladium reagent, the corresponding debrominated products 13a-cto 16a-c were obtained in high to excellent yields. In general, the cycloadducts 13a-c to 15a-c were obtained in 20-40% higher yields via the detour method than those via the direct method. In both routes, the Diels-Alder reactions proceeded in a highly regio- and stereoselective manner to furnish a single cycloadduct in each case.  相似文献   

19.
4-oxo-4-phenylbutanehydrazide 3 was reacted with aryl or alkyl isothiocyanates to give the corresponding N-substituted-2-(4-oxo-4-phenylbutanoyl) hydrazine-1-carbothioamide 4a-c . Cyclization of thiosemicarbazides 4a-c with sodium hydroxide led to the formation of 3-(4-sub-5-thioxo-1,2,4-triazol-3-yl)-propanone 5a-c . Desulfurization of thiosemicarbazides 4a-c by mercuric oxide afforded 3-(5-(sub-amino)-1,3,4-oxadiazol-2-yl)-propanone 6a-c . The reaction of 4a-c with phosphorus oxychloride gave 3-(5-(sub-amino)-1,3,4-thiadiazol-2-yl)-propanone 7a-c . Treatment of 4a-c with ethyl-bromoacetate or α-bromopropionic acid gave N′-(3-sub-thiazolidin-2-ylidene)-butanehydrazide 8a-c and (N′-(3-sub-oxothiazolidin-2-ylidene)-butanehydrazide 9a-c . Chlorination of oxothiazolidine-hydrazide 9a-c by phosphorus oxychloride afforded N-(3-sub-4-oxothiazolidine)-butane-hydrazonoyl-chloride 10a-c . The reaction of 10a-c with mercaptoacetyl-chloride yielded 2-((4-benzoyl-thiopyrane) hydrazono)-3-sub-thiazolidinone 11a-c . Also, reacted of 10a-c with hydrazine hydrate afforded N″-(3-sub-oxothiazolidine)-butane-hydrazon-hydrazide 12a-c . The 3-sub-2-((pyridazine) hydrazono) thiazolidinone 13a-c was obtained by cyclization of 12a-c via refluxing in DMF. The reaction and cyclized of 9a-c with chloroacetyl-chloride in ethanolic KOH afforded 1-((3-sub-4-oxothiazolidine) amino)-azepine-dione 14a-c . The chemical structures of the new compounds have been confirmed by diverse spectroscopy analyses such as IR, NMR, MS, and elemental analysis. The synthesized compounds were tested for their antimicrobial activity and these compounds were considered (Pyridazin-hydrazono-thiazolidinone 13a-c , oxothiazolidin-azepinedione 14a-c , N-thiazolidin-hydrazon-hydrazide 12a-c , and thiopyran-hydrazono-thiazolidinone 11a-c ) the most effective as antimicrobial activity.  相似文献   

20.
Abstract

Reaction of chlorosulfonyl isocyanate (1) with arylaldehyde azines (7) gave the 2:1 crisscross adducts (8);attempts to prepare a disulphonamide of 8a gave only a mixture of the monosulfamide 9 and the diureide 10. The latter with trichloromethanesulfenyl chloride afforded the derivative 12a. and with chlorosulfonic acid hydrazinodicarbonamide (11). The azine 7a with benzoyl isocyanate (2) gave the expected crisscross adduct 13. With thiobenzoyl isocyanate (3) however, both 7a and 7d gave the 1: 1 adducts (14). whereas 7c gave a different 2: 1 adduct (15). Treatment of 14a with 1 gave the ureide 16. With both methyl isocyanate (4) and phenyl isocyanate (S), 7a gave the expected crisscross adducts (17a and b), and 7c with 5 similarly gave 17c. When 7a was treated with 1 followed by aqueous potassium iodide, the diureide (10) was formed; concentrated nitric acid converted 10 into the triazolenone (18). Treatment of 18 with chlorosulfonic acid-thionyl chloride gave the sulfonyl chloride (19) which was characterised as the sulfonamides (20 a-d).

Diarylsulfamoyl azines (21 a-f) with 1 and potassium iodide, gave the diureides 22 a-f. 4-Methoxy-3-sulfamoylbenzaldehydeazines (23 a-c) reacted with 3 to give the 1: I adducts 24 a-c, while 4-chlorosulfonylphenyl isocyanate (6) with benzaldehyde azine (7a) gave the bis-chlorosulfonyl adduct (25a). characterised as the diethylsulfonamide 25b. Attempted chlorosulfonation of the tetraphenyl cycloadduct 17b did not give the tetrasulfonyl chloride (although the reaction was successful with the more reactive rnethoxy adduct 17c); the tetrasulfonyl chloride (26a) was converted into 3 sulfonamides (26 b-d). The unsymmetrically-substituted diaryl azines (27) reacted with 1 and potassium iodide to yield the diureides 28 a-f. Analogous cycloadditions of 1 with several keto azines were unsuccessful. Selected compounds will be screened for medicinal and pesticidal activity; compounds 9,10 and 12a showed fungicidal activity against barley powdery mildew.  相似文献   

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