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1.
A convenient procedure for the synthesis of 2‐spirobenzopyranoquinone 5 and its application to the preparation of spironaphtho[2,3‐b]pyranoquinones 6 and 7 is described. 相似文献
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Mohit Lal Deb 《合成通讯》2013,43(20):3085-3090
6‐Amino‐5‐formyluracils 1 and 5‐formyl‐6‐hydroxyuracils 4 react with Meldrum's acid 2 in the presence of piperidine as catalyst under thermolytic conditions to afford 6‐carboxy‐2,4,7‐trioxopyrido[2,3‐d]pyrimidines 3 and 6‐carboxy‐2,4,7‐trioxopyrano[2,3‐d]pyrimidines 5 in good yield. Under identical conditions, 6‐amino‐5‐nitrosouracils 6 react with 2 to afford pteridine‐6‐carboxylic acids 7 in good yields. 相似文献
4.
Olena V. Il'chenko Oleg V. Zaremba Aliaksandr A. Sherakov Valentin P. Chernykh 《合成通讯》2013,43(15):2559-2568
With the purpose of searching for new biologically active compounds, a method of synthesis of new heterocyclic systems [3‐alkyl(aryl)‐2‐thioxo‐2,3‐dihydro‐1H‐benzofuro[3,2‐d]pyrimidin‐4(1H)‐ones] has been developed. The method is based on the interaction of ethyl 3‐isothiocyanato‐1‐benzofurane‐2‐carboxylate in 2‐propanol with amines in the presence of an equimolecular quantity of triethylamine. 相似文献
5.
Different novel phthalazino[2,3‐b]phthalazine‐5,7,12,14‐tetraones were synthesized in a simple and environmentally benign method from the reaction of phthalic anhydrides with semicarbazide or thiosemicarbazide using montmorillonite K‐10 clay as solid heterogeneous acidic catalyst and microwaves under solvent‐free conditions in good yields and short reaction times. Products were characterized by the elemental analysis, IR, NMR, and mass spectrometry. 相似文献
6.
Pyrano[2,3‐d]pyrimidine derivatives were synthesized in high yields by a condensation reaction between arylmethylidenemalononitrile and barbituric acid using room‐temperature ionic liquids such as 1‐n‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIm]BF4) or 1‐butylpyridinium tetrafluoroborate ([BPy]BF4) as solvents under neutral conditions. 相似文献
7.
The rhodium‐catalyzed hydroformylation of new 1‐(β‐methallyl) indoles 1a–e carried out with Rh4 (CO)12 as the catalyst precursor, at 100 atm total pressure and 100°C, produces the 4-(indol‐1‐yl)‐3‐methylbutanals 2a–e as the sole products in high yields. The synthesized 4‐indolylbutanals are stable under the adopted conditions and are isolated and characterized here for the first time. The preparation of the starting 1‐allylindoles is described too. 相似文献
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The hexopyranosid‐2‐ylidenemalononitrile 1 reacted with phenyl isothiocyanate in the presence of triethylamine to furnish (2R,4aR,6S,10bS)‐8‐amino‐4a,6,10,10b‐tetrahydro‐6‐methoxy‐2‐phenyl‐10‐phenylimino‐4H‐thiopyrano[3′,4′:4,5]pyrano[3,2‐d][1,3]dioxine‐7‐carbonitrile (2). Starting from 1, cyclization with sulphur and diethylamine yielded (2R,4aR,6S,9bR)‐8‐amino‐4,4a,6,9b‐tetrahydro‐6‐methoxy‐2‐phenylthieno[2′,3′:4,5]pyrano[3,2‐d][1,3]dioxine‐7‐carbonitrile (3), which could be transformed into the corresponding aminomethylenamino derivative 4 by treatment with triethyl orthoformate and ammonia. Intramolecular cyclization of 4 to yield (2R,4aR,6S,11bR)‐4,4a,6,11b‐tetrahydro‐6‐methoxy‐2‐phenyl[1,3]dioxino[4″,5″:5′,6′]pyrano[3′,4′:4,5]thieno [2,3‐d]pyrimidin‐7‐amine (5) was achieved by using NaH as base. (2R,4aR,6S,9bS)‐8‐Amino‐4a,6,9,9b‐tetrahydro‐6‐methoxy‐9‐(4‐methylphenyl‐sulfonyl)‐2‐phenyl‐4H‐[1,3]dioxino[4′,5′:5,6]pyrano[4,3‐b]pyrrole‐7‐carbonitrile (6) was prepared by treatment of compound 1 with tosylazide and triethylamine. 相似文献
10.
《合成通讯》2013,43(7):1265-1275
Abstract 4‐Mercapto‐6‐methyl‐2‐pyrone was alkylated with different allylic and propargylic halides under phase transfer catalyzed condition in the presence of TBAB or BTEAC catalyst in chloroform–aqueous NaOH (1%) at room temperature. The S‐alkylated thiopyran‐2‐ones were then refluxed in quinoline or in chlorobenzene to give 4‐chloromethylthiopyrano[2,3‐b]pyran‐2‐one and 4‐hydroxymethylthiopyrano[2,3‐b]pyran‐2‐one or several thieno[2,3‐b]pyran‐2‐ones. 相似文献
11.
《合成通讯》2013,43(24):4557-4563
Abstract 6‐Amino‐5‐cyano‐4‐aryl‐1,4‐dihydropyrano[2,3‐c]pyrazoles were synthesized by three‐component reaction of aromatic aldehydes, malononitrile, and 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one using triethylbenzylammonium chloride (TEBA) as catalyst in aqueous media. The reaction has the advantages of good yield, less pollution, ease of separation, and of being environment friendly. 相似文献
12.
Abstract 1,3‐Dipolar cycloaddition of N‐benzyl nitrone 2 to D‐threo δ‐lactone 15 proceeded with excellent stereoselectivity to provide only one adduct 16. Cycloadduct 16 was subsequently subjected to a sequence of reactions involving rearrangement to γ‐lactone, glycolic cleavage/reduction, protection of the terminal hydroxymethyl group, reduction of the lactone, desilylation/mesylation, and hydrogenolysis of the N‐O bond providing (?)‐isofagomine and its N‐substituted derivatives. The biologic activity of N‐substituted (?)‐isofagomines toward commercially available α‐ and β‐glucosidases, α‐D‐mannosidase, α‐L‐fucosidase, β‐D‐glucuronidase, and β‐D‐galactosidase was tested. 相似文献
13.
Samuel E. Watson 《合成通讯》2013,43(20):2695-2701
A short, high yielding synthesis of a novel substituted pyrrolo[2,3-b]xanthone has been developed. The synthesis begins with a copper catalyzed Ullmann coupling reaction followed by and intramolecular Friedel-Crafts acylation reaction to establish the xanthone core structure. After a regioselective nitration, a Leimgruber-Batcho synthesis establishes the final pyrrole ring. 相似文献
14.
We have obtained dihydrofurans 3a–j in the radical cyclization of 4‐hydroxycoumarin 1a and 2‐hydroxy‐1,4‐naphtoquinone 1b with electron rich alkenes 2a–i by manganese(III) acetate. Methods A and B, which have different molar ratios were studied comparatively in these reactions, and we observed that method B (molar ratio 2:1:3) gave the best results. Treatment of 4‐hydroxycoumarin 1a and electron rich alkenes 2a–e gave 2,3‐dihydro‐4H‐furo[3,2‐c]chromen‐4‐ones 3a–e in 36–86% yields by the method B. Under the same conditions, the reactions of 2‐hydroxy‐1,4‐naphtaquinone 1b with conjugated alkenes 2b and 2f–i afforded 2,3‐dihydronaphtho[2,3‐b]furan‐4,9‐diones 3f–j in an excellent yields. 相似文献
15.
A. Ebenezer Martin 《合成通讯》2013,43(11):1778-1783
A novel method for the synthesis of 6,12‐dihydro‐2‐methylindolo[2,3‐b]carbazol‐6‐ones was developed from 1‐oxo‐2,3,4,9‐tetrahydro‐1H‐carbazol‐1‐one through methyl 6‐methyl‐2‐(1‐oxo‐2,3,4,9‐tetrahydro‐1H‐carbazol‐2‐yl)oxoacetate in good yields. This method provides an alternative path for the synthesis of this product using 2‐hydroxy methylene‐2,3,4,9‐tetrahydro‐1H‐carbazol‐1‐one. 相似文献
16.
The highly stereoselective preparation of cis‐1‐aryl‐2‐benzoyl‐3,3‐dicyanocyclopropanes with arsonium salt and olefin in water is described. It is simple, efficient, and environmentally benign. 相似文献
17.
A new short and highly efficient synthesis of (5)‐2,3‐dimethoxy‐N[(1‐ethyl‐2‐pyrrolidinyl)methyl]‐5‐iodobenzamide (epidepride, 1) from 3‐methoxy‐salicylaldehyde (o‐vanillin, 2) and 3‐methoxysalicyclic acid (6) was achieved by employing a new iodination method with iodine monochloride and iodine nitrate under basic conditions. 相似文献
18.
A series of weakly nucleophilic nitrogen derivatives including carbamates, amides, sulfonamides, and anilines were reacted with 1,2‐bis(trimethylsilyloxy)cyclobutene under acidic conditions to afford various substituted 2‐aminocyclobutanone derivatives 3a–i in modest to excellent yields. 相似文献
19.
A simple route to 7‐formyl‐indole (5) is described in which appropriately functionalized o‐nitrotoluenes (1) are converted to 7‐hydroxymethyl‐indole (4) using the Batcho–Leimgruber process. Condensation of 3‐methyl‐2‐nitrobenzyl alcohol (1a) with N,N‐dimethylformamide dimethyl acetal yields the enamine 2a, which upon catalytic hydrogenation affords 4 in 22% yield. When the hydroxyl function in 1 is protected with pivaloyl or tetrahydropyranyl group, the yields of 4 are increased to 39% and 48%, respectively. Finally, 4 is oxidized with pyridinium chlorochromate (PCC) to afford 5 in 86% yield. 相似文献
20.
The asymmetric synthesis of (+)‐epi‐cytoxazone, a stereoisomer of potent cytokine modulator cytoxazone, starting from anisaldehyde in six steps, is described. The required configuration was established via Sharpless kinetic resolution followed by the Mitsunobu reaction. 相似文献