2311-59-3Relevant articles and documents
Generation and trapping of ketenes in flow
Henry, Cyril,Bolien, David,Ibanescu, Bogdan,Bloodworth, Sally,Harrowven, David C.,Zhang, Xunli,Craven, Andy,Sneddon, Helen F.,Whitby, Richard J.
, p. 1491 - 1499 (2015/03/04)
Ketenes were generated by the thermolysis of alkoxyalkynes under flow conditions, and then trapped with amines and alcohols to cleanly give amides and esters. For a 10 min reaction time, temperatures of 180, 160, and 140 °C were required for >95% conversion of EtO, iPrO, and tBuO alkoxyalkynes, respectively. Variation of the temperature and flow rate with inline monitoring of the output by IR spectroscopy allowed the kinetic parameters for the conversion of 1-ethoxy-1-octyne to be easily estimated (Ea = 105.4 kJ/mol). Trapping of the in-situ-generated ketenes by alcohols to give esters required the addition of a tertiary amine catalyst to prevent competitive [2+2] addition of the ketene to the alkoxyalkyne precursor.
Organocatalytic oxidation of aldehydes to mixed anhydrides
Toledo, Hila,Pisarevsky, Evgeni,Abramovich, Adi,Szpilman, Alex M.
, p. 4367 - 4369 (2013/06/05)
TEMPO catalyzes the direct oxidation of aldehydes to mixed anhydrides in the presence of a carboxylic acid. The anhydrides can be converted in situ to esters, secondary, tertiary or Weinreb amides in high yield. Oxidation of the aldehyde directly to 2-propyl esters is also possible using only catalytic amounts of acid. The oxidation reactions are rapid and take place under mild conditions.
Synthesis and evaluation of different fatty acid esters formulated into Precirol ATO-based lipid nanoparticles as vehicles for topical delivery
Sanna, Vanna,Mariani, Alberto,Caria, Giuseppe,Sechi, Mario
experimental part, p. 680 - 684 (2009/12/26)
A series of isopropyl fatty esters having different chain length (C 13-C23) were synthesized and formulated in lipid nanoparticles based on Precirol ATO to evaluate their effect on the physicochemical properties of these latter. Moreover, drug loading and skin permeation of Econazole nitrate, chosen as a lipophilic model drug, were evaluated as well. The obtained nanosystems, prepared by high shear homogenization method, had a mean diameter ranging from 180 to 280 nm and showed an encapsulation efficiency of about 100%. Ex vivo permeation results demonstrated a parabolic correlation between permeation effect and chain length of the fatty esters present in the lipid nanoparticles formulated in hydrophilic gels. The maximum flux of drug was observed for the nanoparticles containing esters with 17 and 19 carbon atoms, suggesting that these formulations may constitute a potential carrier for topical delivery of econazole nitrate.