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1.
According to reaction conditions, 1,4,7-triketones yield the dihydropyridazine hydrazones (1-8) or the dihydropyrrolo[1,2-b]-pyridazones (9-19). The latter are dehydrogenated by chloranil to the pyrrolo[1,2-b]pyridazines (20-23). 相似文献
2.
Chemistry of Heterocyclic Compounds - This microreview considers methods for the synthesis of pyrrolo[1,2-b]pyridazine derivatives as well as their benzo-fused analogs –... 相似文献
3.
The palladium-catalyzed formal [3+2] cycloaddition reaction of alkylidenecyclopropanes with 1,2-diazines proceeded smoothly to give the corresponding 5-azaindolizine derivatives in good to allowable yields. For example, in the presence of 5 mol % of Pd(PPh(3))(4), the reaction of 1-propylhexylidenecyclopropane with phthalazine or with pyridazine proceeded at 120 degrees C without solvent, and the corresponding 2-(1-butylpentyl)pyrrolo[2,1-a]phthalazine or 6-(1-butylpentyl)pyrrolo[1,2-b]pyridazine was obtained in 61% or 49% yield, respectively. 相似文献
4.
Mendiola J Baeza A Alvarez-Builla J Vaquero JJ 《The Journal of organic chemistry》2004,69(15):4974-4983
A novel and efficient synthesis of the pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine system, the heterocyclic core of the variolin family of marine alkaloids, is described. The route involves the reaction of 3-bromo-2-(bromomethyl)pyrrolo[2,3-b]pyridine and tosylmethyl isocyanide (TosMIC) under phase-transfer conditions. This unprecedented reaction was also used to synthesize a series of new methoxycarbonyl azolopyrimidines by reaction of TosMIC with bromomethylindoles, bromomethylbenzimidazole, and bromomethylpyrazole. Hydrolysis and decarboxylation of 5-bromo-7-methoxycarbonylpyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine obtained by this heterocyclization process and installation of the pyrimidine moiety in the C5 position open an alternative approach to complete a total synthesis of variolin B. 相似文献
5.
Ilyin AP Dmitrieva IG Kustova VA Manaev AV Ivachtchenko AV 《Journal of combinatorial chemistry》2007,9(1):96-106
A series of novel heterocyclic combinatorial libraries containing 4H-thieno[3,2-b]pyrrole, thieno[2',3':4,5]-pyrrol[1,2-d][1,2,4]triazine and thieno[2',3':4,5]pyrrolo[1,2-a]pyrazine heterocyclic moieties were obtained by parallel solution-phase synthesis. Key steps include different reactions of initial alkyl 4H-thieno[3,2-b]-pyrrole-5-carboxylates, such as alkylation with alkylating agents; transformation of the carboxylate group into different reactive functionalities, followed by reactions with electrophilic species; intramolecular cyclizations; and amide bond formation. Simple manual techniques for parallel reactions were coupled with easy purification procedures to give high-purity final products. 相似文献
6.
New synthetic pathways to the 5H-pyrido[3',4':4,5]pyrrolo[2,3-b]quinolines 6, the 6H-pyrido[3',4':4,5]pyrrolo[2,3-b][1,6]naphthyridines 7, and the 11H-pyrido[4',3':4,5]pyrrolo[2,3-b]quinolines 8 via thermolysis of the pyridannulated enyne-carbodiimides 14, 19, and 23 were established. These novel heteroaromatic systems are structurally related to ellipticine alkaloids and could serve as DNA-intercalating agents. 相似文献
7.
A new reaction of N-protected 2-bromomethylazoles and tosylmethyl isocyanide (TosMIC) leading to the preparation of azolopyrimidines is described. This domino sequence was used to synthesize the pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidine core of alkaloids variolins from 4-methoxy-2-methylpyrrolo[2,3-b]pyrimidine in two steps. 相似文献
8.
V. A. Azimov N. N. Bychikhina L. N. Yakhontov 《Chemistry of Heterocyclic Compounds》1982,18(10):1061-1064
The reaction of 7-carbamoyl- and 7-cyano-6-chloro-5-azaindolines with hydrazine leads to the formation of pyrrolo[2,3-d]pyrazolo[5,4-b]pyridine, whereas the reaction of 7-carbamoyl-5-azaindolines with dimethylformamide diethylacetal gives pyrrolo[1,2-c]pyrido]4,3-d]pyrimidines — two new heterocyclic systems. The chemical properties of the synthesized compounds, including cleavage of the pyrimidine ring under the influence of nucleophilic agents, were studied.See [1] for communication 61.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1370–1373, October, 1982. 相似文献
9.
A. A. Druzhinina P. M. Kochergin R. M. Palei O. N. Minailova 《Chemistry of Heterocyclic Compounds》1977,13(2):180-183
The reduction of pyrrolo[1,2-a]imidazole-2-one and pyrrolo[1,2-a]benzimidazole derivatives, which leads to the formation of 2,3-dihydropyrrolo[1,2-a]imidazole derivatives and derivatives of the previously unknown 1,2,3,3a-tetrahydropyrrolo[1,2-a]benzimidazole, was studied. A method was developed for the preparation of 5- and 7-amino derivatives of pyrrolo[1,2-a]imidazole by reduction of the corresponding nitroso- and arylazo-substituted pyrrolo[1,2-a]-imidazoles.See [1] for communication XCI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 225–228, February, 1977. 相似文献
10.
Kawasaki T Ogawa A Terashima R Saheki T Ban N Sekiguchi H Sakaguchi KE Sakamoto M 《The Journal of organic chemistry》2005,70(8):2957-2966
Hexahydropyrrolo[2,3-b]indoles 6 were synthesized in five steps from indolin-3-one 8 by a general and efficient method, in which elements of molecular diversity were readily added onto the 3a-position of the pyrrolo[2,3-b]indole ring system. Horner-Wadsworth-Emmons reaction of 2-allyloxyindolin-3-ones 7, derived from indolin-3-one 8 and a variety of allylic alcohols, smoothly proceeded with successive Claisen rearrangement to give the corresponding 3-allyl-3-cyanomethylindolin-2-ones 15. Indolin-2-ones 15 were converted into pyrrolo[2,3-b]indoles 6 using partial hydrolysis followed by reductive cyclization with LiAlH(4). Synthesis of N-methylated pyrrolo[2,3-b]indole derivatives 23 and 26 is also described. 相似文献
11.
[reaction: see text] Reaction of 5,5-dimethyl-3-pyrazolidinone (1) with 2-indanone (2) gave 5,5-dimethyl-2-(1H-indenyl-2)-3-pyrazolidinone (3) instead of the expected azomethine imine 4. Although reaction of 2-substituted 3-pyrazolidinones with acetylenedicarboxylates usually gives ring expansion products, such as 1,2-diazepines, treatment of 3 with dialkyl acetylenedicarboxylates (5, R = Me; 6 R = Et) resulted in the formation of rel-(7aR,12aS)-6,7-bis(alkoxycarbonyl)-3,4-dihydro-4,4-dimethyl-7aH-indano[1,2-b]pyrrolo[1,2-a]pyrimidin-2-ones (7, R = Me; 9, R = Et) as major products and 3,4-bis(alkoxycarbonyl)-7,7-dimethyl-2-(indenyl-2)-6,7-dihydro-2H,6H-1,2-diazepin-5-ones (8, R = Me: 10, R = Et) as minor products. 相似文献
12.
A two-step selenocyclisation-oxidative deselenaton sequence was used to establish the 3a-hydroxy-pyrrolo[2,3-b]indole core; these tricycles were used as effective precursors to 10b-hydroxy-pyrazino[1',2':1,5]pyrrolo[2,3-b]indole-1,4-diones. 相似文献
13.
Mohammad Piltan 《中国化学快报》2014,25(11):1507-1510
A simple synthetic protocol has been developed involving the three-component reaction between 1,2-diamines, ethyl pyruvate and a-bromo ketones in the presence of Fe Cl3 as a catalyst. A number of pyrrolo[1,2-a]quinoxaline and pyrrolo[1,2-a]pyrazine derivatives were synthesized in excellent yields using this protocol. 相似文献
14.
A. N. Lyshchikov O. V. Pul'kherovskaya A. N. Vasil'ev Ya. S. Kayukov O. E. Nasakin 《Chemistry of Heterocyclic Compounds》2000,36(5):532-536
The scission of the urea group in 5-alkyl-2-amino-3,4-dicyano-N-ureidopyrroles on boiling in KOH solution in DMSO was observed to give 5-alkyl-1,2-diamino-3,4-dicyanopyrroles which were used for the synthesis of pyrrolo[1,2-b][1,2,4]triazepines by reaction with acetylacetone.I. N. Ul'yanov Chuvash State University, Cheboksary 428015, Russia; e-mail: anatoly5@chuvsu.ru. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, 611–616, May, 2000. 相似文献
15.
Pinho e Melo TM Soares MI Rocha Gonsalves AM Paixão JA Beja AM Silva MR Alte da Veiga L Pessoa JC 《The Journal of organic chemistry》2002,67(12):4045-4054
Intramolecular dipolar cycloaddition of bicyclic münchnones, 5H,7H-thiazolo[3,4-c]oxazol-4-ium-1-olates, derived from cyclodehydration of 2-substituted-N-acylthiazolidine-4-carboxylic acids are reported. A range of new pyrrolo[1,2-c]thiazole derivatives (7, 14, 15, 20, 23, and 26) were obtained as single enantiomers from 2-phenylthiazolidines, 2-benzoylthiazolidines, and 2-methylthiazolidine-4-carboxylates. Pyrrolo[1,2-c][1,4]thiazine derivative 27 was also obtained from pyrrolo[1,2-c]thiazole derivative 26. The structures of methyl (2R,4R)-2-(p-methoxybenzoyl)thiazolidine-4-carboxylate (17a), methyl (2R,4R)-2-(p-methoxybenzoyl)-N-(prop-2-ynyloxyacetyl)thiazolidine- 4-carboxylate (18), and 3-oxo-4-phenyl-3,4,6,8-tetrahydro-1H-furo[3',4':2,3]pyrrolo[1,2-c][1,4]thiazine (27) were determined by X-ray crystallography. Chirooptical studies of the pyrrolo[1,2-c]thiazoles were done by confirming the absolute configuration at the chiral center C-3. 相似文献
16.
Ho Sik Kim Yoshihisa Kurasawa Chiemi Yoshii Minako Masuyama Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1990,27(4):1119-1122
The isoxazolo[2,3-a]quinoxalines 11a,b and pyrrolo[1,2-a]quinoxalines 12a,b were selectively synthesized from the 2-substituted 6-chloroquinoxaline 4-oxides 10a,b . The pyrrolo[1,2-a]quinoxalines 12a,b were clarified to be produced by the ring transformation of the isoxazolo[2,3-a]quinoxalines 11a,b . The pyrrolo[1,2-a]quinoxalines 14a,b were obtained from both 2,6-dichloroquinoxaline 4-oxide 9 and compounds 12a,b . 相似文献
17.
Sparrapan R Mendes MA Carvalho M Eberlin MN 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(2):321-326
Two ortho-hetarynium ions, the 2-pyridyl and 2-pyrimidyl cations, react promptly with 1,3-dienes in the gas phase by annulation, formally by fusion, onto the ions of a pyrrole ring. This novel reaction proceeds through an initial polar [4 + 2+] cycloaddition across the C[triple bond]N+ bond, followed by fast ring opening, a [1,4-H] shift, and finally a recyclization that results in a contraction of a six- to a five-membered ring and dissociation by the loss of a methyl radical. For the 2-pyridyl cation, this reaction yields ionized indolizines (pyrrolo[1,2-a]pyridines), while for the 2-pyrimidyl cation, it gives ionized pyrrolo[1,2-a]pyrimidines. The annulation reaction, performed in the rf-only collision quadrupole of a pentaquadrupole (QqQqQ) mass spectrometer, occurs readily with both 1,3-butadiene and isoprene, and is thermodynamically and kinetically favored as predicted by ab initio calculations. Ortho-hetarynium ions and 1,3-dienes provide, therefore, the two building blocks for the efficient one-step gas-phase synthesis of ionized bicyclic pyrrolo[1,2-a]pyridine (indolizine) and pyrrolo[1,2-a]pyrimidine, as well as their analogues and derivatives. 相似文献
18.
A novel synthesis of arylpyrrolo[1,2-a]pyrazinone derivatives 总被引:1,自引:0,他引:1
Some aryl-2-methyl-1-pyrrolo[1,2-a]pyrazinones were designed and prepared to study the Structure-Activity Relationships (SAR) of pyrrolo[1,2-a]pyrazinone derivatives. With methyl pyrrole-2-carboxylate as the starting material, the title compounds were prepared through N-alkylation and two novel cyclizations. Eleven aryl-2-methyl-1- pyrrolo[1,2-a]pyrazinone derivatives not previously reported in the literature are presented in this paper. Some of them show potent anti-inflammatory and analgesic activities. 相似文献
19.
A variety of isoindolo[2,1-a]quinoline derivatives as well as the following related heterocycles have been prepared: 11b,12-dihydro-5H-isoindolo[2,1-b][2]benzazepine-7,13-dione (8a), 7,8,14,14a-tetrahydroisoindolo[2,1-c][3]benzazocine-5, 13-dione (8b), 6a,7-dihydroisoquinolino[2,3-a]quinoline-5,12-dione (12), 2,3,3a-4-tetrahydropyrrolo[1,2-a]quinoline-1,5-dione (14), and pyrido[2',3':3,4]pyrrolo[1,2-a]quinoline-5,11(5H)-dione (17). The key synthetic step involves an intramolecular Friedel-Crafts reaction of acid chlorides such as isoindole-1-acetyl chlorides (4), the acids (3) of which were prepared starting with 2-arylisoindole-1,3(2H)-diones (2-arylphthalimides) (1). The protective effects of isoindolo[2,1-a]quinoline derivatives (19 and 20) against N2-induced hypoxia were examined. Among them, 6-(diethylaminomethyl)isoindolo[2,1-a]quinoline-5,11(5H)-dio ne (19b) showed the most potency. 相似文献
20.
Upon treatment with 30 mol % of Co2(CO)(8) and 30 mol % of TMTU in toluene at 70 degrees C, benzene-bridged alkynecarbodiimides efficiently underwent a ring-closing reaction to give the pyrrolo[2,3-b]indol-2-ones in good yields. These conditions could nearly suppress the formation of the urea derivatives, which were consistently observed when 10 mol % of Co2(CO)(8) and 60 mol % of TMTU in benzene were used. The synthesis of the eight hexahydropyrrolo[2,3-b]indole alkaloids was accomplished from the resulting pyrrolo[2,3-b]indol-2-ones via the introduction of an angular substituent at the C(3a)-position by treatment with NaBH(4)/alkyl bromide as the crucial step. 相似文献