Spiro[5,5]undecane-3-one 1 was converted to 4 ,7-dihydrospiro[benzo[d]thiazole-6(5H),1′-cyclohexane]-2-amine 3 , which is condensed with bromomethyl (halo)phenyl ketones and cyclized to compounds 5a-5c . The X-ray crystallography of the 5b reveals that formation route for 5 is via 3-position-substituted-spiro-iminothiazole 4 . 相似文献
CD trimers (3 and 6) and CD dimers (4 and 7) have been synthesized by reaction of 6-deoxy-6-hydroxyethylamino-β-CD (1) with corresponding 1,3,5-tri(bromomethyl) benzene (2) or 1,3,5-tri (bromomethyl)-2,4,6-trimethylbenzene (5) in the presence of base. 相似文献
Conformationally constrained cyclic alpha-amino acid derivatives were synthesized under solid-liquid phase-transfer catalysis conditions. This methodology involves the bis-alkylation of ethyl isocyanoacetate with various alpha,alpha'-dibromo-o-xylene derivatives [alpha,alpha'-dibromo-o-xylene 5, 2,3-bis(bromomethyl)-1, 4-dimethoxybenzene 6, 1,2-bis(bromomethyl)-4,5-dibromobenzene 7, 2, 3-bis(bromomethyl)naphthalene 8, 1,8-bis(bromomethyl)-naphthalene 9, 6,7-bis(bromomethyl)-2,2-dimethyl-1H-phenalene-1,3(2H)-dione 10, 2, 3-bis(bromomethyl)-1,4-anthraquinone 11, 6, 7-bis(bromomethyl)quinoxaline 12, 3,4-bis(bromomethyl)furan 13, 1,2, 4,5-tetrakis(bromomethyl)benzene 28, and hexakis(bromomethyl)benzene 30] using potassium carbonate as a base and tetrabutylammonium hydrogensulfate as a phase-transfer catalyst to give corresponding isonitrile derivatives, which upon hydrolysis with HCl in ethanol gave amino esters. Using this method electron-deficient as well as electron-rich and halogen-substituted indan-based alpha-amino acids were prepared. The preparation of bis-indan as well as tris-indan alpha-amino esters is also described. 相似文献
Summary: Thermally curable benzoxazine ring‐containing polystyrene macromonomers were synthesized and characterized. 1,4‐Dibromo‐2,5‐bis(bromomethyl)benzene and 1,4‐dibromo‐2‐(bromomethyl)benzene were used as initiators in the atom transfer radical polymerization of styrene. The resulting polymers were used in combination with 3‐aminophenylboronic acid hemisulfate, for a Suzuki coupling. The obtained polymers, with amino groups in the middle or end of the chains, were reacted with formaldehyde and phenol to yield benzoxazine ring‐containing macromonomers. In addition to the glass transition temperature of the polystyrene segment observed at ca. 105 °C, differential scanning calorimetry thermograms exhibit an exotherm at ca. 276 °C corresponding to the oxazine thermal polymerization. Both macromonomers undergo thermal curing with the formation of thermosets having polystyrene segments.
Structure of the benzoxazine‐functionalized polystyrene. 相似文献
Summary : Four monomers; 1,4-bis(1-naphthyl) benzene ( 5 and 7 ) and 1,4-bis(2- thienyl)benzene ( 6 and 8 ) containing one or two polystyrene short chains substituted in 2 or 2, 5 positions of central phenylene ring were synthesized by Suzuki coupling reaction of two polystyrene based macromonomers ( 3 and 4 ) with 1-naphthalene- and 2-thiophene boronic acid, respectively. By chemical oxidative polymerization using FeCl3 as oxidant, copolymers containing alternating phenylene and binaphthyl ( 9 , 11 ) or phenylene and bithienyl groups ( 10 , 12 ) and polystyrene as side chains have obtained. The exact control of polystyrene branch length was performed by atom transfer radical polymerization of styrene using as initiators 1,4 dibromo-2-(bromomethyl)benzene ( 1 ) and 1,4-dibromo-2,5 di(bromomethyl)benzene ( 2 ). Polymers were characterized by FT-IR, 1H-NMR, UV and fluorescence spectroscopy and thermal methods. 相似文献
Starting with the appropriate bis(bromomethyl)naphthalenes, 14a,16a-diazoniaanthra[1,2-a]-anthracene salts ( 6 ), and the 4a,12a- ( 13, 14 ) 4a,8a-( 15 ) and 8a,16a-diazoniadibenzo[b,k]-chrysene ( 16 ) salts have been prepared for the first time. 相似文献
5-Substituted-4-amino-3-thiol-1, 2, 4-triazoles (1a- b) react with orthonitrochloro- benzene or para-nitrochlorobenzene to give N-N bond cleavage products 2a-d, one structure of which (2b) has been unambiguously confirmed by an X-ray structural analysis. 相似文献
The structures of six benzene and three naphthalene derivatives involving bromo, bromomethyl and dibromomethyl substituents, namely, 1,3-dibromo-5-(dibromomethyl)benzene, C7H4Br4, 1,4-dibromo-2,5-bis(bromomethyl)benzene, C8H4Br6, 1,4-dibromo-2-(dibromomethyl)benzene, C7H4Br4, 1,2-bis(dibromomethyl)benzene, C8H6Br4, 1-(bromomethyl)-2-(dibromomethyl)benzene, C8H7Br3, 2-(bromomethyl)-3-(dibromomethyl)naphthalene, C12H9Br3, 2,3-bis(dibromomethyl)naphthalene, C12H8Br4, 1-(bromomethyl)-2-(dibromomethyl)naphthalene, C12H9Br3, and 1,3-bis(dibromomethyl)benzene, C8H6Br4, are presented. The packing patterns of these compounds are dominated by Br…Br contacts and C—H…Br hydrogen bonds. The Br…Br contacts, shorter than twice the van der Waals radius of bromine (3.7 Å), seem to play a crucial role in the crystal packing of all these compounds. The occurrence of Type I and Type II interactions is also discussed briefly, considering the effective atomic radius of bromine, as is their impact on the packing of molecules in the individual structures. 相似文献
A new safe and convenient transformation has been developed. In the presence of cesium formate in dry MeOH solution, α-haloketones underwent direct conversion reaction to afford α-hydroxyketone in excellent yields. Furthermore, this methodology can be extended and applied in 2-chloro-N-(1,3-diphenyl-1H-pyrazol-5-yl)acetamide, 2-chloro-N-(2,6-dimethylphen-yl)acetamide, 1-(bromomethylsulfonyl)benzene, and N-(bromomethyl)phthalimide to give the corresponding products in moderate to excellent yields. 相似文献