Lambi, John N. et al. published their research in Thermochimica Acta in 2003 | CAS: 5003-48-5

4-Acetamidophenyl 2-acetoxybenzoate (cas: 5003-48-5) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.SDS of cas: 5003-48-5

Synthesis, spectral properties and thermal behaviour of zinc(II) acetylsalicylate was written by Lambi, John N.;Nsehyuka, Alfred T.;Egbewatt, Nkongho;Cafferata, Lazaro F. R.;Arvia, Alejandro J.. And the article was included in Thermochimica Acta in 2003.SDS of cas: 5003-48-5 The following contents are mentioned in the article:

The thermal behavior of Zn(II) acetylsalicylate [Zn(acsa)2(H2O)2] with respect to phase transitions, pyrolysis both in air and inert (N2) atm., and product identification was studied. The complex was synthesized by metathesis in hot EtOH solution using aspirin (acetylsalicylic acid) as precursor and characterized via electronic and IR spectral analyses. Optical observations showed that the white salt does not undergo a direct transition from the solid to the liquid phase but rather goes slowly through an intermediate mesophase around 80° before melting rapidly to the brick-brown isotropic liquid around 134-136°. No liquid crystalline phases are however formed. This result was complemented by that from thermogravimetric (TG) studies in the ∼25-600° range, which showed three main weight-loss phases of 8.0, 50.0 and 14.0% (around 200, 250 and 400°) corresponding, resp., to the elimination of CO2, xanthone and HOAc. The pyrolysis products, as identified using a combination of instrumental (GC-MS) and wet chem. techniques are: CO2; nonstoichiometric Zn oxide, most likely in the form: Zn1+xO (0.0000 ≤ x ≤ 0.0003); and a mixture of organic products resulting from further decomposition, charring and other attendant thermal effects at the relatively high temperatures (∼600°) involved. Six of the principal organic products were identified and included salsalate and benorylate which are pro-drugs of salicylic acid, a known pharmaceutical. This study involved multiple reactions and reactants, such as 4-Acetamidophenyl 2-acetoxybenzoate (cas: 5003-48-5SDS of cas: 5003-48-5).

4-Acetamidophenyl 2-acetoxybenzoate (cas: 5003-48-5) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.SDS of cas: 5003-48-5

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics