- SYNTHESIS OF POLYFUNCTIONAL ALIPHATIC CARBONYL COMPOUNDS UNDER PHASE-TRANSFER CONDITIONS
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We have studied mono- and dialkylation of malonic, acetoacetic, and cyanoacetic esters with esters of haloacetic and β-halopropionic acids and addition of the CH acids mentioned and their analogues to methyl and ethyl acrylate under phase-transfer catalysis conditions, and also deethoxycarbonylation of the obtained products.We have demonstrated for the first time the possibility of Dieckmann cyclization under phase-transfer catalysis conditions and have developed a simple method for the synthesis of 2,3-di(ethoxycarbonyl)cyclopentanone, a key intermediate in the synthesis of deoxyprostaglandins, by cyclization of triethyl 1,2,4-butanetricarboxylate.
- Sizov, A. Yu.,Dombrovskii, V. A.,Yanovskaya, L. A.
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- SYNTHESIS OF CYANOCARBOXYLIC ACID ALKYL ESTERS
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Provided is a process for obtaining a compound of formula (I): N≡C-CH2-A-C(O)-OR, wherein Hal is halogen selected from F, Cl, Br or I, A denotes a bond or a divalent spacer selected from alkylene and arylene groups, and R is a C1-4 alkyl group, by reacting a compound of formula (II): Hal-CH2-A-C(O)-OR, wherein Hal is a halogen atom selected from F, Cl, Br and I, and wherein A and R are as defined above, with hydrogen cyanide in the presence of a first base, wherein the molar ratio between hydrogen cyanide and said first base is from 1:0.3 to 1:0.95 and the molar ratio between hydrogen cyanide to the compound of formula (II) is at least 1:1.
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Page/Page column 30-31
(2013/08/28)
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- Synthesis of a γ-lactam library via formal cycloaddition of imines and substituted succinic anhydrides
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Formal cycloaddition reactions between imines and cyclic anhydrides serve as starting point for the synthesis of diverse libraries of small molecules. The synthesis of succinic anhydrides substituted with electron-withdrawing groups is facilitated by new mild conditions for alkylation of aryl-substituted acetyl esters with ethyl bromoacetate. These anhydrides are then used in formal cycloaddition reactions with imines to produce γ-lactams. 2-Fluoro-5-nitrophenylsuccinic anhydride reacts efficiently with imines to provide lactams that are further diversified by conversion of the nitro group to either an aniline and an azide for subsequent reactions with acylating agents and alkynes, respectively. The synthesis of cyanosuccinic anhydride is reported for the first time, and the use of this compound in reactions with imines and subsequent functionalization of the resultant lactams is demonstrated.
- Tan, Darlene Q.,Atherton, Amy L.,Smith, Austin J.,Soldi, Cristian,Hurley, Katherine A.,Fettinger, James C.,Shaw, Jared T.
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scheme or table
p. 218 - 223
(2012/05/07)
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- Process for production of 2,5 dioxopyrrolidine 3 carboxylate
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The present invention provides a novel intermediate which enable to prepare tetrahydropyrrolo[1,2-a]pyrazin-4-spiro-3′-pyrrolidine derivatives such as Ranirestat being promising therapeutic agents for diabetic complications in a short process and in an economically advantageous and safe manner, and a process for preparing the same. That is, the present invention provides a process for preparing a compound of the following formula (I) wherein R1 is an amino group protected with a protecting group, etc., and R2 is a lower alkyl group, etc., comprising the following steps (1) and (2): (1) a step of converting a cyano group in a compound of the following formula (II) wherein n and m are each independently 0 or 1; provided when n is 0 and m is 1, then R2 and R3 are the same or different protecting groups for a carboxyl group; and when n is 1 and m is 0, then R2 and R3 are the same protecting groups for a carboxyl group; and R1 is as defined above, into a carbamoyl group in the presence of divalent palladium compound(s), primary amide(s) and water; and (2) a step of cyclizing the product obtained in the step (1).
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Page/Page column 6
(2011/08/08)
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- One-Pot Synthesis of cis Fixed β-Diketones of Bicycloalkanes, 2
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Starting from 2-cycloalken-1-ones 1 the substituted cis fixed β-diketones of bicycloalkanes 4 have been obtained by a combined Michael addition of α,α,ω-alkanetricarboxylates (and related species) 2 and Dieckmann cyclization of the intermediates 3.Reactions of the β-diketone system as well as modifications of the disubstituted malonate system of 4 are reported.
- Schank, Kurt,Lorig, Werner
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p. 112 - 136
(2007/10/02)
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