A New Access to Diarylmaleic Anhydrides

Abstract

A new three‐step synthesis of diarylmaleic anhydrides 6, starting from 3‐aryl‐2‐hydroxybut‐2‐enedioates 2, is reported.

Synthesis and Structure of 5-Indolyl-6-thienyl-1,2,4-triazines

“…By analogy with published data [24,6], reactions of X with carboxylic acids led to formation of 3-substituted 6-(2,5-dimethyl-3-thienyl)-7-(3-indolyl) [1,2,4] Thus the results of our study showed that 2-(3-indolyl)-1-(2,5-dimethyl-3-thienyl)ethanedione can be used as starting compound for the synthesis of 1,2-dihetarylethenes in which the indole and thiophene rings are linked through various 1,2,4-triazine-containing bridges. Compound IX reacts with hydrazine to afford the corresponding hydrazino derivative X.…”

Stereoselective synthesis of oxazolidinonyl-fused piperidines of interest as selective muscarinic (M 1 ) receptor agonists: a novel M 1 allosteric modulator

“…N-(1-tert-Butyldimethylsilyloxy-2-cyclobutylbut-3-en-2-yl) 2,2,2trifluoroacetamide (19). The mixture of trifluoroacetimidates (Z)-and (E)- 18 (11.1 g, 31.6 mmol) in xylene (900 mL) was heated under reflux for 18 h then cooled to rt.…”

“…18 Using Pd(PPh 3 ) 4 in the presence of lithium chloride and copper(1) iodide, the Stille coupling of the enol triflate 68 with 2-tributylstannylfuran gave the required alkene 65. 19 Preliminary studies were also carried out into the Pd(0) catalysed coupling of the enol triflate with other metalated heterocycles. Thus treatment of an excess of 5-lithio-2-phenyl-1,3-oxazole 20 with zinc chloride gave the corresponding organozincate that was coupled with the triflate 68 in the presence of PdCl 2 (PPh 3 ) 2 as the catalyst to give the coupled 1,3-oxazole 69 albeit in only a modest yield, see Scheme 8.…”

New classes of functionalized parylenes and poly(phenylene vinylene)s via coupling of dihaloxylyl diesters

“…2a, the unsaturated analogue, PPV-acid, was prepared by exposing BrPPX-2f to an aqueous solution of KOH as treatment with an aqueous solution of HCl appeared to afford anhydride side products. 28,52 The carboxylic acid product exhibited a broad absorption over the range of 3000 to 3600 cm −1 and a v CvO at 1566 cm −1 (Fig. 2b).…”