- Environmentally benign decarboxylative: N-, O-, and S-Acetylations and acylations
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An operationally simple and general method for acetylation and acylation of a wide variety of substrates (amines, alcohols, phenols, thiols, and hydrazones) has been reported. Meldrum's acid and its derivatives have been used as an air-stable, non-volatile, cost-effective, and easy to handle acetylating/acylating agent. Easily separable byproducts (CO2 and acetone) allowed the isolation of analytically pure acetylated products without the requirement of work-up and any chromatography. This journal is
- Ghosh, Santanu,Purkait, Anisha,Jana, Chandan K.
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supporting information
p. 8721 - 8727
(2020/12/30)
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- Ethyl acetate as an acetyl surrogate for the iodine catalyzed acetylation of alcohols
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The use of readily available ethyl acetate in the presence of iodine as an alternative acetylating agent is reported. Amines and phenols were unreactive under the examined reaction conditions, indicating that the method is highly chemoselective.
- Basumatary, Grace,Bez, Ghanashyam
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p. 4312 - 4315
(2017/10/13)
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- Chemoselective N-deacetylation under mild conditions
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A mild and efficient chemoselective N-deacetylation using the Schwartz reagent at room temperature in rapid time is described. The mild and neutral conditions enable orthogonal N-deacetylation in the presence of some of the common protecting groups (viz. Boc, Fmoc, Cbz, Ts). The deprotection conditions did not induce any epimerization at the chiral amino centre.
- Sultane, Prakash R.,Mete, Trimbak B.,Bhat, Ramakrishna G.
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supporting information
p. 261 - 264
(2014/01/06)
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- Hydrophobic effect and substrate specificity in reaction of thioester and amine in water
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The extent of hydrophobic effect in amidation reaction of alkyl thioester with alkylamine in water was studied. The yield of the products was primarily dependent on the alkyl group of amine. For example, the reaction of S-dodecyl dodecanethioate with dodecylamine proceeded in good yield, while the reaction did not occur with cyclohexylamine, piperidine, and dipropylamine. The effect of chain length of n-alkylamine was studied to suggest the presence of hydrophobic effect. The yield of amide also depended on the alkyl group of the thioester secondarily, but the effect was smaller than amine.
- Torihata, Atsushi,Kuroda, Chiaki
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experimental part
p. 1534 - 1538
(2011/02/23)
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- Hydrolysis and stability of acetylsalicylic acid in stearylamine-containing liposomes
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The hydrolysis and the stabilization of acetylsalicylic acid (ASA) in liposomes at 30°C were studied. The liposomes consisted of dimyristoylphosphatidylcholine (DMPC) and stearylamine. At pH 4.0 and 8.0, the pseudo-first-order rate constants (k(obs)) in DMPC: stearylamine (2:1 mole ratio) liposomes were approximately 60% of the values in control solutions (k(B)) if ASA was incorporated via the organic phase. In contrast, when ASA was added via the aqueous phase, k(obs) = k(B) at pH 4.0 but k(obs) k(B) at pH 8.0 and k(obs) increased with the fraction of stearylamine in the liposomes. However, when ASA was added via the organic phase, reactions occurred which resulted in the loss of ASA as a function of the time period between phase admixture and the point of film hydration. A product of the reactions was determined by IR and TLC to be N-stearylacetamide. Both the initial loss of ASA and the increase in stability decreased as the DMPC:stearylamine mole ratio increased. A mechanism of aminolysis occurring in the organic solvent and at liposome surfaces between ASA and stearylamine or DMPC at pH 8.0 has been suggested. It is concluded that the orientation of ASA and the ordered structural environment of the bilayers minimizes the aminolytic and hydrolytic reactions.
- Habib,Rogers
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p. 496 - 499
(2007/10/02)
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- Decreased stability in liposomal suspensions: Accelerated loss of p-nitrophenyl acetate
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The goal of this investigation was to determine the reason for the previously reported increase in the rate of hydrolysis of p-nitrophenyl acetate to p-nitrophenol in the presence of positively charged liposomes. When this charge was due to incorporation
- Pejaver,Notari
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p. 1167 - 1171
(2007/10/02)
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