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Triethyl Amine (triethyl + amine)
Selected AbstractsA study of the reaction between 2,4-disubstituted-2,3-dihydro-1,5-benzothiazepines and ketenes generated in situ from chloro and dichloroacetyl chloridesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2001Qi-Yi Xing In the presence of triethyl amine, the reaction of 2,4-disubstituted-2,3-dihydro-1,5-benzothiazepine with chloro and dichloroacetyl chlorides produced not only the expected ,-lactam derivative of the benzo-thiazepine, but also the ring opening product. Different results were obtained when the substituent at 2-position of the benxothiazepine varied from methyl to aryl, and the substituent on the chloroacetyl chloride varied from H to Cl, or when carrying out the reaction at different temperatures. The structures of the obtained products and the reaction mechanism are discussed. [source] Reactivity studies of ethyl(Z)- N -(2-amino-1,2-dicyanovinyl) formimidate with carbonyl compounds in the presence of base,JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2000M. Joséalves The reaction of ethyl(Z)- N -(2-amino-1,2-dicyanovinyl)formimidate 6 with carbonyl compounds in the presence of triethyl amine occurs with formation of the Schiff s base and intramolecular hydrolysis of the adjacent cyano group to give the alkylideneamino derivatives 8a-f. When the ,-carbon of the ketone has at least one proton, the prolonged contact of 8a-f with triethylamine causes intramolecular cyclization between this carbon and the imidate carbon atom to form a seven membered ring. This is followed by cyclization of the cyano and amido groups, leading to the pyrrolo[4,3- b][1,4]diazepines 9. If a strong base is used the first ring to be formed is the pyrrole ring as evidenced in the reaction of 8a with 1,8-diazabicyclo[5.4.0]undec-7-ene leading to 14. The subsequent addition of methyl amine to the reaction mixture, caused cleavage of the alkylideneamino unit and formation of the amidine function from the imi date (15). The addition of acid to the imidates 8a and 8f led to the diazepine compounds 10a and 10f respectively. A suspension of compound 8e in ethanol and triethylamine evolved to a pyrazinone structure 12 under kinetic conditions (4 hours, room temperature) and to the pyrrolo[4,3- b][1,4]diazepine 9e under thermodynamic conditions (48 hours, room temperature). [source] Temperature and pH sensitive ionic hydrogels based on new crosslinkersPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2005Ayman M. Atta Abstract New crosslinkers were synthesized from reaction of melamine with acryloyl and methacryloyl chloride in the presence of 1-methyl-2-pyrrolidone as a solvent and triethyl amine as acid acceptor. The chemical structures of the prepared crosslinkers were elucidated from FT-IR, 1H-NMR and 13C-NMR analyses. Linear 2-acrylamido-2-methyl-1-propane sulfonic acid and methacrylic acid (AMPS/MAA) copolymers were prepared and their viscometric properties in aqueous solution were investigated. Different weight percentages of the prepared crosslinkers were used as crosslinking agent (AMPS/MAA) to prepare ionic copolymers using ammonium persulfate as initiator. The percentage of crosslinkers was varied from 0.5 to 4,wt%. The swelling behaviors of crosslinked AMPS/MAA gels in deionized water were measured at different pH and temperatures. All AMPS/MAA copolymers exhibit faster deswelling rate at 50°C except for the copolymer containing 0.9 (mol ratio) AMPS. Copyright © 2005 John Wiley & Sons, Ltd. [source] The DMAP-Catalyzed Acetylation of Alcohols,A Mechanistic Study (DMAP=4-(Dimethylamino)pyridine)CHEMISTRY - A EUROPEAN JOURNAL, Issue 16 2005Shangjie Xu Dr. Abstract The acetylation of tert -butanol with acetic anhydride catalyzed by 4-(dimethylamino)pyridine (DMAP) has been studied at the Becke3,LYP/6-311+G(d,p)//Becke3,LYP/6-31G(d) level of theory. Solvent effects have been estimated through single-point calculations with the PCM/UAHF solvation model. The energetically most favorable pathway proceeds through nucleophilic attack of DMAP at the anhydride carbonyl group and subsequent formation of the corresponding acetylpyridinium/acetate ion pair. Reaction of this ion pair with the alcohol substrate yields the final product, tert -butylacetate. The competing base-catalyzed reaction pathway can either proceed in a concerted or in a stepwise manner. In both cases the reaction barrier far exceeds that of the nucleophilic catalysis mechanism. The reaction mechanism has also been studied experimentally in dichloromethane through analysis of the reaction kinetics for the acetylation of cyclohexanol with acetic anhydride, in the presence of DMAP as catalyst and triethylamine as the auxiliary base. The reaction is found to be first-order with respect to acetic anhydride, cyclohexanol, and DMAP, and zero-order with respect to triethyl amine. Both the theoretical as well as the experimental studies strongly support the nucleophilic catalysis pathway. [source] Synthesis and Characterization of , -Bromo Chalcone DerivativesCHINESE JOURNAL OF CHEMISTRY, Issue 8 2009Yakup BUDAK Abstract , -Bromo chalcones containing 2-thiene ring were prepared in good yields by the condensation of 1-(thien-3-yl)ethanone with aromatic aldehydes, followed by bromination with bromine and selective dehydrobromination with triethyl amine at room temperature. [source] | ||||||||||