91570-07-9Relevant academic research and scientific papers
Synthesis of sulfur-containing tricyclic ring systems by means of photoinduced decarboxylative cyclizations
Griesbeck, Axel G.,Oelgemoeller, Michael,Lex, Johann,Haeuseler, Andreas,Schmittel, Michael
, p. 1831 - 1843 (2007/10/03)
The intramolecular and intermolecular photoinduced electron transfer reactions of a series of mercaptoacetic acid and mercaptopropionic acid derivatives were investigated. In the intermolecular series, the phthalimidoalkylsulfanylalkylcarboxylates 1a-j and 2 were transformed into the tricyclic ring systems 3a-j and 4, respectively, with high regioselectivities. The mercaptoacetic acid and 2-mercaptopropionic acid derived substrates 1a-g and 2 readily cyclized in good to excellent yields (60-98%) but with low diastereoselectivities (except for 1d), whereas the corresponding 3-mercaptopropionic acid derived substrates 1h-j gave the corresponding tricyclic products 3h-j after prolonged irradiation, but with poor yields (11-20%). The intermolecular version - i.e., photodecarboxylative addition to N-methylphthalimide (5) as electron acceptor - was successful with mercaptoacetic acid, and 2-mercaptopropionic acid substrates 6a-c and the addition products 7a-c were obtained in high yields (57-90%). No addition, however, was observed with 3-(methylsulfanyl)propionic acid (6d). The regioselectivity of decarboxylation proceeded in a controlled manner for the mercaptosuccinic acid derivatives in both the intramolecular (with 8a-c) and the intermolecular (with 9) versions. Comparison between sulfur-activated and nonactivated species (13, 15) or irradiation of la under nonactivating conditions showed that the carboxylate anion in the position ct to the electron-donating sulfur atom acts as a superior leaving group. This efficiency is drastically reduced for carboxylate anions in the β position. With the former substrates, the photochemical cyclization proceeds with high product yields. Quantum yield measurements for decomposition (Φd as a measure for cyclization) supported these observations. CV measurements indicated preorientation prior to electron transfer in the intramolecular pathway.
Development of monoclonal ELISAs for azinphos-methyl. 1. Hapten synthesis and antibody production
Mercader, Josep V.,Montoya, Angel
, p. 1276 - 1284 (2007/10/03)
The development of monoclonal antibody-based enzyme-linked immunosorbent assays for azinphosmethyl is described. A panel of haptens was synthesized for immunoconjugate preparation, and a series of haptens for heterologous, coating or tracer, conjugates was also prepared. Hapten synthesis was based on a strategy in which only a fragment of the whole target molecule was present (fragmentary haptens). From immunized mice, a set of monoclonal antibodies was obtained and ELISA sensitivities were assayed in different formats. Affinities estimated as I50 values in the low nanomolar range for azinphos-methyl and phosmet were observed for several monoclonal antibodies in the conjugate-coated format and in the antibody-coated format under nonoptimized assay conditions.
