19483-24-0Relevant academic research and scientific papers
Haloacetylated Enol Ethers. 8 [12]. Reaction of β-Alkoxyvinyl Trihalomethyl Ketones with Guanidine Hydrochloride. Synthesis of 4-Trihalomethyl-2-Aminopyrimidines
Zanatta, Nilo,Cortelini, Maria De F. M.,Carpes, Marcos J. S.,Bonacorso, Helio G.,Martins, Marcos A. P.
, p. 509 - 513 (1997)
In this work the results of the reaction of β-alkoxyvinyl trihalomethyl ketones 1, 2a-e, with guanidine hydrochloride are reported. Depending on the ketone 1 or 2 and the conditions under which the reactions were carried out, 4-trihalomethyl-2-amino pyrimidines, β-alkoxyvinyl carboxylic acids, or β-acetal carboxylic esters were obtained.
INHIBITORS OF BRUTON'S TYROSINE KINASE AND METHODS OF THEIR USE
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Page/Page column 333, (2018/06/30)
Compounds of formula (I') and methods of their use and preparation, as well as compositions comprising compounds of formula (I').
INHIBITORS OF BRUTON'S TYROSINE KINASE AND METHODS OF THEIR USE
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Page/Page column 334, (2017/09/02)
The present disclosure is directed to compounds of formula I and methods of their use and preparation, as well as compositions comprising compounds of formula I.
2-Ethoxyvinyllithiums and diethoxyvinyllithiums: What makes them stable or fragile?
Schlosser, Manfred,Wei, Heng-Xu
, p. 1735 - 1742 (2007/10/03)
The elusive (E)-2-ethoxyvinyllithium can be readily generated in tetrahydrofuran at -75 °C from (E)-1-bromo-2-ethoxyethylene by halogen/metal exchange and subsequently trapped with electrophiles. Alkylation opens a convenient entry to (E)-configurated enethers. (E)-2-Ethoxyvinyllithium decomposes rapidly at -50 °C whereas its (Z)-isomer, which lacks the possibility to eliminate lithium ethoxide in a favorable anti-periplanar process, is stable under the same conditions. (E)-1,2-Diethoxyvinyllithium even sustains reflux temperatures (approximately 75 °C). 2,2-Diethoxyvinyllithium and (Z)-1,2-diethoxyvinyllithium can be conserved at 0 °C although this time loss of alcoholate can occur in the anti-mode. Obviously it matters whether the energy-rich ethoxyacetylene is formed as the elimination product or simple acetylene, as in the case of (E)-2-ethoxyvinyllithium.
Electroorganic Synthesis, 56. Synthesis of Advanced Prostaglandin Precursors by Kolbe Electrolysis, I. - Preparation of (1'R,4'S,3R/S)-3-(cis-4-Acetoxycyclopent-2-enyloxy)-3-ethoxypropionic Acid
Weiguny, Jens,Schaefer, Hans J.
, p. 225 - 234 (2007/10/02)
The key intermediate of a novel synthesis of prostaglandin precursors, (1'R,4'S,3R/S)-3-(cis-4-acetoxycyclopent-2-enyloxy)-3-ethoxypropionic acid (3), is prepared by two different synthetic sequences: In a first strategy transacetalization of ethyl 3,3-diethoxypropionate (6) with (1R,4S)-4-acetoxy-1-hydroxy-2-cyclopentene (7) leads to the formation of the mixed acetal 8.By subsequent hydrolysis and acylation 8 could be converted into acid 3 in six steps in 6percent overall yield.However, the generation of acid 3 by bromoalkoxidation of 3-ethoxyacrylates 13d, e and subsequent electrochemical reduction proved to be more efficient.In this reduction it is possible to debrominate the α-bromo esters 14d, e and to remove the 2-haloethyl ester group in one step.Using this reaction sequence, we could synthesize acid 3 in five steps in 38percent overall yield. - Key Words: Kolbe electrolysis / Radical cyclization / Electrochemical dehalogenation / Prostaglandins
A Convenient Synthetic Method for β-Alkoxy- and β-Phenoxyacrylic Acids and 3,4-Dihydro-2H-pyran-5- and 2,3-Dihydrofuran-4-carboxylic Acids
Hojo, Masaru,Masuda, Ryoichi,Sakaguchi, Syuhei,Takagawa, Makoto
, p. 1016 - 1017 (2007/10/02)
trans-β-Trihaloacetylvinyl ethers 1 are easily hydrolyzed by wet potassium hydroxide in benzene, yielding the corresponding acids 2 in excellent yields.This synthetic method also can be applicable to cyclic vinyl ethers 3 and 5 to yield 4 and 6 in high yi
