24653-75-6Relevant articles and documents
HETEROCYCLIC COMPOUND, APPLICATION THEREOF AND PHARMACEUTICAL COMPOSITION COMPRISING SAME
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Paragraph 1110-1111, (2020/12/08)
Disclosed in the present invention are a heterocyclic compound, an application thereof and a pharmaceutical composition comprising the same. Provided by the present invention are a heterocyclic compound represented by formula I or a pharmaceutically acceptable salt thereof. The compound has a novel structure and a good inhibitory activity against autotaxin (ATX).
Chemodivergent Preparation of Various Heterocycles via Phase-Transfer Catalysis: Enantioselective Synthesis of Functionalized Piperidines
Bernardi, Luca,Bertuzzi, Giulio,Fochi, Mariafrancesca,Mazzanti, Andrea,Moimare, Pierluigi,Pecorari, Daniel,Silvestrini, Filippo
supporting information, (2020/02/11)
In this work, a new chemodivergent domino approach for the preparation of various saturated heterocycles, based on phase-transfer catalysis (PTC), is presented. The versatile nature of doubly electrophilic substrates, showing both a Michael acceptor and a ketone, tethered by a heteroatom, enables three different domino reaction pathways. The nucleophile dictates the chemoselectivity of the reaction. Sulfa-Michael/aldol, cyanide addition/oxa-Michael and Michael/H-shift/aldol processes, along with the variation of the tethering heteroatom, results in the formation of six different classes of saturated heterocycles. DFT calculations account for the observed chemo- and diastereoselectivity of the two most productive processes. Moreover, an extensive investigation on the sulfa-Michael/aldol pathway was carried out, ultimately leading to the development of a new enantioselective domino approach to multi-substituted piperidines based on PTC. (Figure presented.).
Synthesis of 5-Membered Sulfur Heterocycles via Tin-Catalyzed Annulation of Mercapto Ketones with Activated Alkenes
Suzuki, Itaru,Sakamoto, Yuki,Seo, Yuta,Ninomaru, Yoriko,Tokuda, Kodai,Shibata, Ikuya
, p. 2759 - 2769 (2020/01/31)
Efficient conversion of α-mercapto ketones 1 with activated alkenes 2 into S-heterocycles was developed with Sn(Oct)2-2MeOH acting as a catalyst. Two types of products, dihydrothiophene 3 and thiolane 4, were obtained. The selectivity of the products was dependent on the reaction temperature and on the rearrangement of the S-heterocycles from 3 to 4 under heating conditions. The dihydrothiophenes 3 were transformed into useful thiolactones 6-8 and thiophene 9.
Straightforward synthesis of 2-acetyl-substituted benzo[b]thiophenes
Debray, Julien,Lemaire, Marc,Popowycz, Florence
, p. 37 - 40 (2013/02/23)
Described herein is a green one-step protocol for the preparation of substituted 2-acetylbenzo[b]thiophenes from commercially available aromatic halides. This efficient method has the advantage of using water as the reaction medium, resulting in a high yield of pure cyclized products. Two scaffold types have been prepared using this general procedure: 2-acetylbenzo[b]thiophenes and 2-acetyl-3-aminobenzo[b]thiophenes, both crystallized directly from the reaction mixture, due to their low solubility with water, and without the need for an additional purification step. Georg Thieme Verlag Stuttgart · New York.
USE OF THIAZOLE COMPOUND IN FLAVOR APPLICATIONS
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, (2012/10/08)
The present invention has discovered that 2-ethyl-4-methyl-2,5-dihydro-thiazole possesses unexpected and advantageous flavor properties.
Synthesis and chemistry of 4,5-dihydrothieno[3,2-b]pyrrol-6-ones - A heteroindoxyl
Gaywood, Alexander P.,McNab, Hamish
supporting information; experimental part, p. 4278 - 4282 (2009/09/08)
(Chemical Equation Presented) Flash vacuum pyrolysis (FVP) of 2-acetyl-3-azidothiophene gives 3-methylthieno[3,2-c]isoxazole as the major product at a furnace temperature of 350°C whereas at temperatures above 550°C the new heteroindoxyl 4,5-dihydrothieno[3,2-b]pyrrol-6-one is exclusively formed. The heteroindoxyl exists predominantly as the keto tautomer. It is O-protonated by TFA, N-acetylated by acetic anhydride, N-nitrosated by nitrous acid, and provides an N-methylene Meldrum's acid derivative on treatment with methoxymethylene Meldrum's acid. Reactions of 4,5-dihydrothieno[3,2-b] pyrrol-6-one with diazonium salts, with isatin, and with dimethyl acetylenedicarboxylate take place at the methylene position to provide a hydrazone, an indirubin analogue, and a succinate derivative, respectively. Oxidation of 4,5-dihydrothieno[3,2-b]pyrrol-6-one gives a heteroindigotin, which shows a hypsochromic shift in the UV spectrum, relative to indigotin itself.
Evaluation of the Key Odorants in a Thermally Treated Solution of Ribose and Cysteine by Aroma Extract Dilution Techniques
Hofmann, Thomas,Schieberle, Peter
, p. 2187 - 2194 (2007/10/02)
Application of the aroma extract dilution analysis on a solvent extract isolated from a thermally treated solution (145 deg C; 20 min) of cysteine/ribose led to the identification of 2-furfurylthiol, 3-mercapto-2-pentanone, 2-methyl-3-furanthiol, 5-acetyl-2,3-dihydro-1,4-thiazine, 3-mercapto-2-butanone, and bis(2-methyl-3-furyl) disulfide showing the highest flavor dilution factors among the 29 odor-active volatiles.HRGC/olfactometry of decreasing headspace volumes established especially 2-furfurylthiol and 2-methyl-3-furanthiol as important odorants and revealed 2-thenyl mercaptan and ethyl mercaptan as further key contributors to the overall roasty, meatlike, sulfury odor of the model mixture. 5-acetyl-2,3-dihydro-1,4-thiazine, identified for the first time among the volatiles of Maillard model reactions or foods, exhibited an intense roasty, popcorn-like odor at the low odor threshold of 0.06 ng/L of air, which was of the same order of magnitude as those reported in the literature for the roasty-smelling odorants 2-acetyl-1-pyrroline and 2-acetyl-2-thiazoline.Keywords: Aroma extract dilution analysis; nonenzymatic browning; Maillard reaction; ribose; cysteine; flavor; 5-acetyl-2,3-dihydro-1,4-thiazine
Gas-phase SN2 and E2 reactions of alkyl halides
DePuy, Charles H.,Gronert, Scott,Mullin, Amy,Bierbaum, Veronica M.
, p. 8650 - 8655 (2007/10/02)
Rate coefficients have been measured for the gas-phase reactions of methyl, ethyl, n-propyl, isopropyl, tert-butyl, and neopentyl chlorides and bromides with the following set of nucleophiles, listed in order of decreasing basicity: HO-, CH3O-, F-, HO- (H2O), CF3CH2O-, H2NS-, C2F5CH2O-, HS-, and Cl-. For methyl chloride the reaction efficiency first falls significantly below unity with HO- (H2O) as the nucleophile and for methyl bromide with HS- as the nucleophile; in both cases the overall reaction exothermicity is about 30 kcal mol-1. Earlier conclusions that these halides react slowly with stronger bases are shown to be in error. In the region where the rates are slow oxygen anions react with the alkyl chlorides and bromides by elimination while sulfur anions of the same basicity react by substitution. This difference is due to a slowing down of elimination with the sulfur bases; sulfur anions show no increased nucleophilicity as compared to oxy anions of the same basicity. Rate coefficients have also been measured for reaction of methyl fluoride with HO- and CH3O- and ethylene oxide with HO-, CH3O-, and F-. All of these rates are slow but measurable; combining the results of these experiments with those of the alkyl chlorides and bromides suggests that the gas-phase barrier to the symmetrical SN2 reaction of F- with methyl fluoride is lower than previous estimates. We have also measured rates for reaction of allyl chloride with F-, H2NS-, and HS-, chloromethyl ether with H2NS- and HS-, chloroacetonitrile with F-, H2NS-, HS-, and 37Cl-, bromoacetonitrile with Cl- and 81Br-, and α-chloroacetone with H2NS-, HS-, and 37Cl-. Our results also imply that the gas-phase SN2 barrier for Br- reacting with methyl bromide is nearly equal to the ion-dipole attraction energy of the reactants, in agreement with previous estimates.
Identification of Volatile Flavor Components of the Oil from Roasted Sesame Seeds
Nakamura, Shuichi,Nishimura, Osamu,Masuda, Hideki,Mihara, Satoru
, p. 1891 - 1900 (2007/10/02)
The volatile extract obtained by steam distillation of the oil from roasted sesame seeds was seperated into its neutral, weakly acidic, acidic and basic fractions.The neutral fraction was further seperated by preparative TLC.All fractions were analyzed by means of a gas chromatograph (GC) equipped with FID and FPD, and by gas chromatography/mass spectrometry (GC/MS) and/or gas chromatograhy/Fourier transform-infrared (GC/FT-IR) spectrometry.Two hundred and twenty one constituents were identified.One hundred and forty six of these compounds are being reported for the first time in the aroma of roasted sesame seeds, 7 of which were newly identified as naturally occurring flavor components.Two dithioketones, 1-methyldithio-2-propanone and 1-methyldithio-2-butanone, are new compounds.
