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Condensation of the tetrahydropyranyl ether of the α-hydroxyalkyl-thioamides with 3-bromo-4-hydroxy-2-pentanones yields DL -2-(α-hydroxyalkyl)-4-methyl-5-(β-hydroxyethyl)-thiazoles. By oxidation with chromic anhydride 2-hydroxymethyl-4-methyl-5-(β-acetoxyethyl)-thiazole yields the corresponding 2-formyl derivative. The latter compound reacted with GRIGNARD complexes gives the homologous DL -2-(α-hydroxyalkyl)-4-methyl-5-(β-hydroxyethyl)-thiazoles. This is a general method for the synthesis of the thiazole part of the «active aldehydes». 2-Acetyl-4-methyl-5-(β-hydroxyethyl)-thiazole is also obtained by chromic oxidation of the suitable methylthiazol-2-yl-carbinol. The condensation of the thioamides obtained from the α-ethoxycarbonyl-nitriles with 3-bromo-5-acetoxy-2-pentanone results in the DL -2-(α-ethoxycarbonyl-alkyl)-4-methyl-5-(β-acetoxyethyl)-thiazoles. The α-hydroxyl function is introduced into the 2-(α-ethoxycarbonyl-alkyl) group by chlorination with sulfuryl chloride and replacement of the introduced chlorine by acetate. The latter compounds are the esters of the thiazole part of the «active α-oxo-carboxylic acids» (e.g. active pyruvate, etc.). The reaction of 2-(α-hydroxyalkyl)-4-methyl-5-(β-hydroxyethyl)-thiazoles and 2-(α-ethoxycarbonyl-α-acetoxy-alkyl)-4-methyl-5-(β-acetoxyethyl)-thiazoles, respectively, with alkyl, alkenyl and aralkyl haloids, or with 2-methyl-4-amino-5-bromomethyl-pyrimidine hydrobromide results in the quaternary thiazolium compounds belonging to the group of the active aldehydes, active α-oxo-carboxylic acids, etc. According to this method 2-hydroxymethyl-thiamine bromide hydro-bromide has been synthesized, which can be considered as the pyrophosphate-free «active formal-dehyde». The 2-α-hydrogen atom in 2-(α-hydroxyalkyl)-thiazolium compounds cannot be replaced by deuterium under conditions similar to those used for the H → D exchange in thiamine. The main peaks in the mass spectra of 2-(α-hydroxyalkyl) substituted thiazoles and thiazolium quaternary salts are listed. 相似文献
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5-(α-Fluorovinyl)tryptamines 4a, 4b and 5-(α-fluorovinyl)-3-(N-methyl-1′,2′,5′,6′-tetrahydropyridin-3′- and -4′-yl) indoles 5a, 5b were synthesized using 5-(α-fluorovinyl)indole ( 7 ). The target compounds are bioisosteres of 5-carboxyamido substituted tryptamines and their tetrahydropyridyl analogs. 相似文献
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Friedrich Boberg Karl-Heinz Garburg Karl-Joachim Grlich Eberhard Pipereit Elke Redelfs Maria Ruhr 《Journal of heterocyclic chemistry》1986,23(6):1853-1859
From α-nitroolefines 1 and β-diketones 2 3-acetyl4,5-dihydro-5-(methy1eneamino)furans 5 are prepared. Furans 5 react in acid medium to yield 1-unsubstituted 3-acylpyrroles 6 , catalytic hydrogenation yields 1-substituted 3-acylpyrroles 9 . The 1H-nmr and 13C-nmr investigations prove the constitutions. 相似文献
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H. Sabrowsky E. Feldbaum-Mller K. Fischer S. Sitta P. Vogt V. Winter 《无机化学与普通化学杂志》1996,622(1):153-156
The Crystal Structures of α- and β-K3OCl The orange coloured compound K3OCl has been prepared. It exists in a low temperature modification (α-K3OCl) and a high temperature modification (β-K3OCl). The transition temperature is 364 ± 5 K. The crystal structures were determined by x-ray diffraction. α-K3OCl crystallizes at room temperature in the orthorhombic space group Pbnm (Z = 4) with the cell parameters a = b = 723.9(2) pm and c = 1 027.7(2) pm in the anti-GdFeO3-structure type. The high temperature modification β-K3OCl crystallizes (Z = 1) in the cubic space group Pm3m in the β-Ag3SI-structure type with a = 516.2(2) pm (T = 393 K). 相似文献
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Synthesis and Spectroscopical Properties of Di(phthalocyaninato(1?))lanthanidepolybromide; Crystal Structure of α-Di(phthalocyaninato)samariumpolybromide, α-[Sm(Pc)2]Br1.45 and α-Di(phthalocyaninato)samariumperchlorate, α-[Sm(Pc)2](ClO4)0.63 Bronze-coloured di(phthalocyaninato)lanthanidepolybromide, [Ln(Pc?)2]Bry (Ln = La…(? Ce, Pm)…Lu; y > 1.5) is prepared by oxidation of (nBu4N)[Ln(Pc2?)2] with bromine in excess. The UV-VIS-NIR spectra show the typical B and Q1 bands of the Pc? ligand at ~ 14 kK and ~ 20 kK. For the [Ln(Pc?)2]+ cation a NIR(D) band between 9,14 kK (La) and 11,50 kK (Lu) is characteristic for dimeric cofacial Pc? radicals. Within the row La…Lu, there is a linear relationship of the hypsochromic shift of the strong bands and the LnIII radius. In the case of La? Nd the D band shifts successively with longer time of bromination to ~ 3 kK as a result of increasing electron delocalisation. Characteristic vibrational bands are at ~ 1350/1450 cm?1 (IR) and ~ 560/1120/1170/1600 cm?1 (RR). In the FT-Raman spectra the totally symmetric Ln? N stretching vibration between 141 cm?1 (La) and 172 cm?1 (Lu) is selectively enhanced. As shown by α-[Sm(Pc)2]Br1,45 and α-[Sm(Pc)2](ClO4)0,63 only partially ringoxidized complexes are obtained by the anodic oxidation. Both crystallize in the tetragonal space group P4/nnc. The [Sm(Pc)2] molecular building block contains two nearly planar staggered (~41°) Pc rings packed in columns parallel along [001] leading to the quasi-one-dimensional structure. There is a statistical disorder of the SmIII and the ClO4? resp. Br?/Br3? ions over two incompletely filled crystallographic positions for the cation resp. anion. This results in a partial oxidation of the Pc ligand, which in the picture of localized valence states for α-[Sm(Pc)2](ClO4)0,63 corresponds to [SmPc?Pc2?] · 2[Sm(Pc?)2](ClO4). Accepting the same valence state for [Sm(Pc)2]Br1,45 five positive charges are compensated by two Br? and three Br3?. The spectroscopic differences of the partially and fully oxidized complexes are discussed. 相似文献