Pyridyl acrylic acids

Heating the crystalline salt 2-aminopyridinium propiolate (346) at 100 °C in the solid state led to a 10 9 mixture of 2/f-pyrido[l,2-n]pyrimidin-2-one and ( )-3-(2-imino-l,2-dihydro-l-pyridyl)acrylic acid (347). Analysis of differental scanning calorimetry data shows unambiguously that the reaction takes place in the solid state. An endothermic peak at 81.1 °C corresponds to a solid state reaction, and a peak at 122-123 °C is attributed to melting. The product ratio of 2//-pyrido[l, 2-n]pyrimidin-2-one and 347 is 1 2.5 at 60°C, and 1 1.4 at 80°C (94MI12). 

Butyl lithium (10 ml, 1.64 mol in hexane) was added under nitrogen to a stirred suspension of triphenyl-2-pyrrolidinoethylphosphonium bromide (7.2 g) in dry toluene (75 ml). After 0.5 h, ((E)-3-(6-(4-toluoyl)-2-pyridyl)acrylate, vide supra, (4.8 g) in toluene (50 ml) was added. The suspension, initially orange, became deep purple, then slowly faded to yellow during 2 h heating at 75°C. The cooled solution was diluted with ether (150 ml) and treated with hydrochloric acid (50 ml, 2 mol). The aqueous phase was separated, washed with ether, and basified with potassium carbonate (ice) and extracted with ether. The mixture of isomeric esters obtained by evaporation was dissolved in ethanol (100 ml) containing sodium hydroxide solution (20 ml, 1 mol) and partially evaporated on the steam bath under reduced pressure for 5 min. The residual aqueous solution was neutralized with sulfuric acid (20 ml, 0.5 mol) and evaporated to dryness. The solid residue was extracted with hot isopropanol (3x50 ml) and the extracts were concentrated until crystallization commenced. The (E)-3-(6-(3-pyrrolidino-l-(4-tolyl)prop-l-(E)-enyl)-2-pyridyl)acrylic acid, melting point 222°C (dec. recrystallization from isopropanol) was obtained. 

Phenylpropionic acid, racemic mixture /ra s-3-(3-pyridyl)acrylic acid coating molecular imprinting, 3 pm 50 mMNaH2P04, pH 4.65... 

The methyl betaines of 3-(2-pyridyl)acrylic acid (90) and 3-(4-pyridyl)acrylic acid (91) behave slightly differently on Lukes reduction. A piperidine derivative results in the former case (90), and a... 

Another material to demonstrate this hard-soft acid-base preferences to assemble d- f- metal architectures is YATRER [Cu3(CgH6N02)6Nd2(N03)6] (Fig. 29) (106). This compound uses frani-3-(3-pyridyl)acrylic acid (3-HPYA)... 

Mercaptothiophene has been added to various acrylic acids the Michael adducts (545) have been cyclized to (546) (Equation (50)) <88JOC9>. (4-Pyridyl)acrylic acid gave an anomalous product—the... 

In a related work, Vittal and coworkers reported on salts with cations, as opposed to anions, that undergo photodimerizations wherein the stereochemistry was anion controlled. Specifically, formation of the trifluoroacetate and sulfate salts of ( )-3-(4-pyridyl)acrylic acid (4-pa) and subseqnent photodimerization generated head-to-tail and head-to-head dimers, respectively (Figure 20a and b). The C=C bonds were separated on the order of 3.7 A. Head-to-tail and head-to-head geometries were dictated by N-H- 0, O-H- O, and C-H- -O hydrogen forces. 

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