Functional polymers. XVI. Synthesis and polymerization of 2(2-hydroxy-5-isopropenylphenyl)-2H-benzotriazole and a new synthesis of 2(2-hydroxy-5-vinylphenyl)2H-benzotriazole

2(2-Hydroxy-5-isopropenylphenyl)2H-benzotriazole was synthesized in 40% overall yield starting from o-nitroaniline. Diazotization in aqueous hydrochloric acid gave o-nitrophenyl diazonium chloride which was condensed with p-hydroxyacetophenone; the azo compound was reduced to 2(2-hydroxy-5-acetylphenyl) 2H-benzotriazole with zinc powder in sodium hydroxide solution and the 2-hydroxy group of the compound was acetylated. Treatment of the acetyl compound with methyl Grignard reagent resulted in the methylation of the 5-acetyl group to 2[2-acetoxy-5(2-hydroxy-2-propyl)phenyl]2H-benzotriazole which was then dehydrated with potassium hydrogen sulfate to the desired 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole. This monomer did not homopolymerize, but was copolymerized readily with styrene, methyl methacrylate, and n-butyl acrylate with azobisisobutyronitrile as the initiator. 2(2-Acetoxy-5-acetylphenyl)2H-benzotriazole was also reduced with sodium borohydride to form 2[2-acetoxy-5-(1-hydroxyethyl)phenyl]2H-benzotriazole which was dehydrated and hydrolyzed to the known 2(2-hydroxy-5-vinylphenyl)-2H-benzotriazole. This route provides a novel and simpler synthesis of 2(2-hydroxy-5-vinylphenyl)2H-benzotriazole.     

Oriental Lacquer. 11. Botany and Chemistry of the Active components of Poisonous Anacardiaceae

Abstract

Some aspects of the botany of the family Anacardiaceae are discussed with special emphasis on the poisonous genera and species. The focus is on the well-known members of the genus Toxicodendrons, i.e., the lacquer tree, poison ivy, poison sumac, and poison oak. These genera have as their toxic, dermatitis-causing ingredients catechols with C₁₅ and C₁₇ aliphatic side chains of various degrees of unsaturation and a variety of compositions of the individual components. Saps with a catechols mixture of a high triene content are used as lacquer for highly desired objects of art and daily use with great beauty and considerable value. Some other members of the Anacardiaceae family which grow in South East Asia have active catechol and phenol components with slightly different chemical side chain structure.     

Syntheses of 5-Fluorouracil-Terminated Monomethqxypqly(Ethylene Glycol)S,Their Hydrolysis Behavior,and Their Antitumor Activities

The covalent attachments of 5-fluorouracil (5FU) units to poly(ethylene glycol) monomethoxy ether (MeO-PEG) attached through ester, amide, and ether bonds were carried out; three types of linkages were obtained through which 5FU units were attached to MeO-PEG. For the investigation of the release of the 5FU units, the homogeneous hydrolysis was investigated in vitro in the presence and absence of enzymes. Although the rate of release of l-β-carboxyethyl-5FU or 1-β-hydroxyethyl-5FU from the compounds was fast, the release of 5FU itself was slow. In addition, the antitumor activity of these three types of MeO-PEG-bound 5FU unit was tested in vivo by preliminary screening by the National Cancer Institute or by the Japanese Foundation for Cancer Research.     

Macromolecular Architecture for the 21st Century

Abstract

The success of civilizations and technologies has always depended on the efficient use of the available materials.     

Bestimmung der Gerbs?ure

Ohne Zusammenfassung     

Ueber die Zersetzbarkeit des Jodkaliums

Ohne Zusammenfassung     

Polycationic Salts V [1]. 15N NMR Spectra of Amines, Ammonium Salt Monomers, and Polymers of Styrene Based Trialkylammonium Salts

Summary.  ¹⁵N NMR spectroscopy was found to be essential for the detailed characterization of tertiary amines, vinylbenzylammonium salts, and polymers derived from these compounds. It proved important for the characterization of low 2-ionene oligomers and vinylbenzylammonium salts derived thereof as well. The polymers of these novel monomers were also characterized and identified. Received November 25, 1999. Accepted (revised) January 10, 2000     

The Table of Standard Atomic Weights—An exercise in consensus

The present Table of Standard Atomic Weights (TSAW) of the elements is perhaps one of the most familiar data sets in science. Unlike most parameters in physical science whose values and uncertainties are evaluated using the “Guide to the Expression of Uncertainty in Measurement” (GUM), the majority of standard atomic-weight values and their uncertainties are consensus values, not GUM-evaluated values. The Commission on Isotopic Abundances and Atomic Weights of the International Union of Pure and Applied Chemistry (IUPAC) regularly evaluates the literature for new isotopic-abundance measurements that can lead to revised standard atomic-weight values, A_r°(E) for element E. The Commission strives to provide utmost clarity in products it disseminates, namely the TSAW and the Table of Isotopic Compositions of the Elements (TICE). In 2016, the Commission recognized that a guideline recommending the expression of uncertainty listed in parentheses following the standard atomic-weight value, for example, A_r°(Se) = 78.971(8), did not agree with the GUM, which suggests that this parenthetic notation be reserved to express standard uncertainty, not the expanded uncertainty used in the TSAW and TICE. In 2017, to eliminate this noncompliance with the GUM, a new format was adopted in which the uncertainty value is specified by the “±” symbol, for example, A_r°(Se) = 78.971 ± 0.008. To clarify the definition of uncertainty, a new footnote has been added to the TSAW. This footnote emphasizes that an atomic-weight uncertainty is a consensus (decisional) uncertainty. Not only has the Commission shielded users of the TSAW and TICE from unreliable measurements that appear in the literature as a result of unduly small uncertainties, but the aim of IUPAC has been fulfilled by which any scientist, taking any natural sample from commerce or research, can expect the sample atomic weight to lie within A_r°(E) ± its uncertainty almost all of the time.