13152-54-0Relevant academic research and scientific papers
Synthesis, DFT study and the Eschenmoser sulfide contraction of 1,2,3,4-tetrahydropyrimidine derivatives
Akbas, Esvet,Erdogan, Ahmet,Ergan, Erdem,Gulcan, Mehmet,Ruzgar, Adem
, p. 269 - 277 (2017/05/22)
5-Substituebenzoyl-4-aryl-6-substituephenyl-1,2,3,4-tetrahydro-2-(thioxo, oxo and imino) pyrimidines (4a-d) were synthesized via multicomponent cyclocondensation reaction. 7-Benzoyl-8-phenyl-6-(4-carboxyphenyl)-2,3-dihydropyrimido[2,1-b][1,3]thiazin-4(6H)-one (5), 6-benzoyl-2-methyl-7-phenyl-5-(4-carboxyphenyl)-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a] pyrimidine (6) and 6-benzoyl-7-phenyl-5-(4-carboxyphenyl)-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a] pyrimidine (7) were synthesized via reactions of starting compound 4e [1] and appropriate reagent compounds. When 4e was treated with α-bromoester in 1,4-dioxane (1/10 mL) it was resulted like the Eschenmoser sulfide contraction and compounds 8 was obtained. This method generally requires tertiary phosphine but instead of it we used pyridine as a catalyst. In addition, all synthesized pyrimidine derivatives have been optimized geometrically with DFT in Gaussian at the B3LYP/6-31G(d, p) level in order to obtain information about the 3D geometries and electronic structures. (Chemical Equation Presented).
Porphyrins with exocyclic rings. Part 22: Synthesis of deoxophylloerythroetioporphyrin (DPEP), three ring homologues, and five related nonpolar bacteriopetroporphyrins using a western ring closure and an improved b-bilene methodology
Lash, Timothy D.,Li, Wei,Quizon-Colquitt, Desiree M.
, p. 12324 - 12342 (2008/03/13)
Dipyrrolic intermediates incorporating five-membered carbocyclic rings are easily prepared from cyclopenta[b]pyrroles, and this unit represents the southern half of the DPEP-type geoporphyrins found in organic-rich sediments such as oil shales and petroleum. Related dipyrroles with six-, seven- or eight-membered carbocyclic rings were shown to give b-bilenes when reacted with dipyrrylmethane carbaldehydes under mildly acidic conditions. Following deprotection of the terminal ester groups, cyclization with TFA-CH(OMe)3 gave a series of ring homologues of deoxophylloerythroetioporphyrin (DPEP). The b-bilenes generated from the five-membered ring dipyrroles proved to be rather unstable and had to be used directly without purification. Cyclization gave DPEP contaminated with an etioporphyrin by-product, but these could be separated as the nickel(II) derivatives by flash chromatography. This approach gave superior yields of DPEP compared to previously reported methods. In addition, the methodology could be extended to the synthesis of related petroporphyrins, and a series of five molecular fossils derived from bacteriochlorophylls d were synthesized by this approach.
New oxidation of β-hydroxy α-methyl ketones: A convenient synthesis of 3-methylalkane-2,4-diones
Yuasa, Yoshifumi,Kato, Yasushi
, p. 628 - 631 (2013/09/06)
The synthesis of 3-methylalkane-2,4-diones, which are intense strawlike and fruit-flavored compounds, has been performed by the aldol condensation of n-alkanal (C2-C7) and methyl ethyl ketone to give 4-hydroxy-3-methyl-2-alkanones in 31-72% yield, followed by oxidation using sodium hypochlorite in the presence of 4-benzoyloxy-2,2,6,6-tetramethyl-piperidine-Noxide in 60-86% yield.
