- Synthesis of benzofurans from the cyclodehydration of α-phenoxy ketones mediated by Eaton’s reagent
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Cyclodehydration of α-phenoxy ketones promoted by Eaton’s reagent (phosphorus pentoxide–methanesulfonic acid) is used to prepare 3-substituted or 2,3-disubstituted benzofurans with moderate to excellent yields under mild conditions. The method provides a facile access to benzofurans from readily available starting materials such as phenols and α-bromo ketones. The reaction is highly efficient, which is attributed to the good reactivity and fluidity of Eaton’s reagent. The reaction can be applied to prepare naphthofurans, furanocoumarins, benzothiophenes, and benzopyrans.
- Ma, Lin,Ma, Zhanwei,Zhang, Min,Zhou, Min
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p. 426 - 436
(2020/03/23)
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- Metal-Free Synthesis of Furocoumarins: An Approach via Iodine-Promoted One-Pot Cyclization between 4-Hydroxycoumarins and Acetophenones
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A transition metal-free approach was developed to achieve substituted furocoumarins via an iodine-promoted one-pot cyclization between 4-hydroxycoumarins and acetophenones. High yields of furocoumarins were achieved in the presence of NH4OAc as
- Pham, Phuc H.,Nguyen, Que T. D.,Tran, Nhu K. Q.,Nguyen, Vu H. H.,Doan, Son. H.,Ha, Hiep Q.,Truong, Thanh,Phan, Nam T. S.
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p. 4431 - 4435
(2018/09/11)
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- [Hydroxy(tosyloxy)iodo]benzene in organic synthesis: A facile synthesis of furo[3,2-c]coumarins using-tosyloxyketones
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Facile synthesis of furo[3,2-c]coumarins (2a-g) via cyclocondensation of 4-hydroxycoumarin and-tosyloxyketones (1a-g) is described. A plausible mechanism involving C-C bond formation followed by 5-exo-tet cyclization is suggested.
- Prakash, Om,Wadhwa, Deepak,Hussain, Khalid,Kumar, Ravi
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experimental part
p. 2947 - 2951
(2012/07/27)
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- Regio and diastereoselective synthesis of functionalized 2,3-dihydrofuro[3,2-c]coumarins via a one-pot three-component reaction
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An efficient and straightforward synthesis of furo[3,2-c]coumarins via the one-pot three-component condensation of aromatic aldehydes, 4-hydroxycoumarin and α-chloroketones in refluxing n-propanol is described. Pyridine or a mixture of AcOH and AcONH4 was used as a basic catalyst.
- Altieri, Elisa,Cordaro, Massimiliano,Grassi, Giovanni,Risitano, Francesco,Scala, Angela
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experimental part
p. 9493 - 9496
(2011/01/12)
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- Antineoplastic α-methylene-γ-butyrolactones
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The present invention provides antineoplastic α-methylene-γ-butyrolactones represented by the general formula ?I! wherein R1 is a phenyl group optionally substituted with one or two groups selected from the group consisting of halide, (C1
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- α-methylene-γ-butyrolactones: new inhibitors of platelet aggregation
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The present inventors have discovered three classes of novel α-methylene-γ-butyrolactones with excellent antiplatelet activity. As a result of intensive studies, it has been found that compounds represented by the formula I-III are potent inhibitors of platelet aggregation. STR1 For the formula I, R1 is a methyl, a phenyl group optionally substituted with one or two group selected from halide, (C1 -C4) alkyl, (C1 -C4) alkoxy, phenyl, nitro, amino. For the formula II, R1 is a methyl, a phenyl group optionally substituted with one or two group selected from halide, (C1 -C4) alkyl, (C1 -C4) alkoxy, phenyl, nitro, amino; R2 represents hydrogen, halide, (C1 -C4) alkyl, phenyl, nitro, amino; R3 represents hydrogen, halide, (C1 -C4) alkyl, phenyl, nitro, amino. For the formula III, R1 is a methyl, a phenyl group optionally substituted with one or two group selected from halide, (C1 -C4) alkyl, (C1 -C4) alkoxy, phenyl, nitro, amino; R4 represents hydrogen, hydroxy, (C1 -C4) alkyl. The present invention also provides a cost-efficient method for the preparation of formula I-III. Formula I-III may be administered orally or parenterly with an inert diluent or with a pharmaceutically acceptable carrier in the treatment or the prevention of cardiovascular disease.
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- Synthesis of coumarin derivatives as inhibitors of platelet aggregation
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In a search for the inhibitors of platelet aggregation, certain coumarin derivatives were synthesized and evaluated for antiplatelet activity against thrombin(Thr)-, arachidonic acid(AA)-, collagen(Col)-, and platelet-activating-factor(PAF)-induced aggreg
- Chen, Yeh-Long,Wang, Tai-Chi,Lee, Kuan-Han,Tzeng, Cherng-Chyi,Chang, Ya-Ling,Teng, Che-Ming
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p. 651 - 657
(2007/10/03)
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