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1.
3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give 5-acetyl-3-alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Chlorination of 6-hydroxymethyl-1,4-dioxan-2-ones with thionyl chloride and subsequent dehydrochlorination led to formation of 6-methylene-1,4-dioxan-2-ones. 相似文献
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In the pursuit of biologically active compounds we required as a key intermediate 2,3-dihydro- 1,3-benzoxaz-bones having a halomethylene moiety at C(2), i.e. 3 (R2 = H or alkyl, R3 = CH2X). The standard procedure for the preparation of this class of compounds is the condensation of salicylamide derivatives 1 with the proper aldehyde1-5 and ketone5,6. Usually, hydrochloric acid or sulphuric acid is used as catalyst and the water formed is cocornmittently removed using a dehydrating agent or by azeotropic destillation7. These procedures did not serve our purpose as the required α-substituted aldehyde or ketone as such is unstable under the conditions employed. Here we report that employment of acetals and ketals 2 affords the desired compound 3; yields are appreciable when the proper reaction conditions are used. 相似文献
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Summary. The reaction of 2-aminomethylene-2,3-dihydropyrrol-3(1H)-ones with ethyl bromoacetate, chloroacetonitrile, or dilute HCl gave rise to a series of methine dyes, namely 1-aryl-2-[3-hydroxy-1-aryl-4,5-diphenyl-1H-pyrrol-2-yl]methylene-4,5-diphenyl-2,3-dihydropyrrol-3(1H)-ones. 相似文献
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Hélio A. Stefani Adriano S. VieiraMônica F.Z.J. Amaral Leora Cooper 《Tetrahedron letters》2011,52(33):4256-4261
Herein we report an approach to the formation of 5-alkynyl-1,3-dioxin-4-ones using Suzuki-Miyaura cross-coupling reaction of potassium alkynyltrifluoroborate salts with 2,2,6-trimethyl-5-iodo-1,3-dioxin-4-one. The resulting 5-ethynyltrimethylsilyl-1,3-dioxin-4-ones obtained through the Sonogashira reaction were further reacted in a Cu(I)-catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition to form functionalized 1,4-disubstituted-1,2,3-triazoles in good yields, using mild conditions and ultrasonic radiation to expedite the reaction. 相似文献
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Xuetong Li Dr. Jordi Benet-Buchholz Dr. Eduardo C. Escudero-Adán Prof. Arjan W. Kleij 《Angewandte Chemie (International ed. in English)》2023,62(11):e202217803
A conceptually novel catalytic domino approach is presented for the synthesis of highly functional 1,4-dihydro-2H-1,3-benzoxazine-2-one derivatives. Key to the chemoselectivity is a proper design of the precursor to override thermodynamically favored parasitic cyclization processes and empower the formation of the desired product through Thorpe–Ingold effects. The synthetic diversity of these CO2-based heterocycles is further demonstrated, and the isolation of a reaction intermediate supports an unusual ring-expansion sequence from an α-alkylidene, five-membered cyclic carbonate to a six-membered cyclic carbamate by N-induced isomerization. 相似文献
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Musalova M. V. Musalov M. V. Udalova S. I. Khabibulina A. G. Potapov V. A. Amosova S. V. 《Russian Journal of General Chemistry》2018,88(8):1751-1753
Russian Journal of General Chemistry - Tellurium tetrabromide readily reacted with 2-allylphenol at room temperature in acetonitrile to give previously unknown... 相似文献
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Condensation of 2H-naphth[2,3-d][3,1] oxazin-2,4 (IH)-dione (1) with schiff bases (2) in acetic acid resulted in the formation of 2,3-dihydro-2,3-diarylbenzo[g]quinazolin-4(IH)-ones (3). Reaction of 1 with ketoanils generated in situ results in 2,3-dihydro-2,2-substituted-3-phenylbenzo[g]quinazolin-4 (IH)-ones (6) and the spiroalkanes (5). Dehydrogenation of 3 gave 2,3-diaryl benzo[g]quinazolin-4(3H)-ones (7). 相似文献
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以邻硝基苯甲酸衍生物为底物,经3或4步反应,并在第3步关环反应中使用了乙酰丙酮钼和三氟甲磺酸铜作为催化剂,合成了10个新型的1,4-苯并二氮杂?-5-酮三氟乙基和环丙基取代衍生物(4a~4f, 5a~5b, 6a~6b),其结构经1H NMR, 13C NMR和HR-MS(ESI)表征。测试了目标化合物对慢性骨髓性白血病细胞、乳腺癌、肺癌和宫颈癌等4种肿瘤细胞系的抑制活性。结果表明:化合物2-(丙-1-烯-2-基)-4-(2,2,2-三氟乙基)-1,2,3,4-四氢-5H-苯并[e][1,4]二氮杂-5-酮(4a)对慢性骨髓性白血病细胞K562的IC50可达2.6 μM;目标化合物对肺癌A549、乳腺癌MDA-MB-231和宫颈癌HeLa细胞系也表现出一定的抑制活性。 相似文献
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Baeyer-Villiger rearrangement of substituted flavanones using MCPBA affords ring-expanded products, shown by NMR spectroscopy to be the corresponding 3,4-dihydro-4-phenyl-1,5-benzodioxepin-2-ones. 相似文献
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Erich Kleinpeter Manfred Mühlstdt Peter Kuhl 《Magnetic resonance in chemistry : MRC》1977,9(11):661-662
The preferential conformation of some 3-substituted 1,4-benzoxathianes has been determined by means of 1H n.m.r. spectroscopy. 相似文献
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Methyl acetoacetate and 2,4-pentanedione dianions were condensed with aldehydes and ketones to afford a 1,3,5-trioxygenated carboskeleton. Intramolecular cyclization of the aldol adducts delivered the title compounds in good yield. 相似文献
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S.V Yemets Yu.P BanderaV.M Timoshenko Yu.G Shermolvich 《Journal of fluorine chemistry》2002,115(2):175-181
1-Benzylsulfonyl-1,1-dihydropolyfluoroalkan-2-ones react with phthalimidosulfenyl chloride or succinimidosulfenyl chloride to form the sulfenylated products on the active methylene group, 1-benzylsulfonyl-1-phthalimido(succinimido)thiopolyfluoroalkan-2-ones. Decomposition of the latter leads to formation of 1-benzylsulfonyl-1-thioxopolyfluoroalkan-2-ones. These compounds easily undergo the hetero Diels-Alder reaction with electron-rich 1,3-dienes as dienophiles and with electron-rich olefins as hetero-1,3-dienes. Polyfluoroalkyl substituted derivatives of six-membered sulfur-containing heterocycles, 5,6-dihydro-2H-thiins and 2,3-dihydro-1,4-oxathiins, are obtained as a result of these reactions. 相似文献
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M. Hannoun M.
ini D. Kolbah F. Kajfe N. Bla
evi 《Journal of heterocyclic chemistry》1981,18(5):963-965
α-Haloacetanilides Ia-e react with hexamine in ethanol giving the bisimidazolidin-4-one derivatives IIa-e, which hydrolize, in acidic media into the corresponding mono-imidazolidin-4-ones IIIa-e. The compounds IIa-d were converted into 1,4-benzodiazepin-2-ones, under different conditions and in the presence of a variety of agents. The yields were between 50 and 100%. 相似文献
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A series of novel 1,4-benzoxazine-2,3-dicarboximides starting from maleic anhydride and substituted aromatic amines were synthesized. 相似文献
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以三苯基氯化锡和二苯碳酰二肼为原料,在乙醇-钠中反应合成了一个新型的氯化三苯基锡(1,4-二氢-2,3-二苯基四氮唑酮)配合物(1),其结构经FT-IR,元素分析和X-射线单晶衍射表征。结果表明:1(CCDC: 1 445 377)属单斜晶系,P21/c空间群,晶胞参数a=1.393 2(6) nm, b=1.097 3(5) nm, c=1.933 7(8) nm, β=110.219(9) ,V= 2.77 4(2) nm3, Z=4, Dc=1.498 g·cm-3, F(000)=1 264, R1=0.028 8, wR2=0.064 6。中心Sn为五配位三角双锥构型。研究了1的荧光性质、热稳定性、电化学性质和体外抗癌活性。结果表明:1在100 ℃下较稳定; 1在400 nm(λex=320 nm)处有弱荧光峰;c(1)=5 μg·mL-1时,对HeLa细胞株增殖的抑制率为93.70%。 相似文献