CCCLXXXV.—Some substitution products of azobenzene

Biological synthesis of l-ascorbic acid in animal tissues: conversion of l-gulonolactone into l-ascorbic acid

“…In species requiring dietary ascorbic acid, e.g. the guinea pig, the liver enzyme has been found to convert D-glucuronic acid into L-gulonic acid (Hill & Chaikoff, 1956;Burns, 1957). It has also been observed to contain the necessary lactone-forming enzyme converting L-gulonate into L-gulonolactone.…”

“…Mi88ing link in the guinea pig. Guinea-pig liver is known to contain the enzyme system converting D-glucuronicacidintoL-gulonic acid (Hill & Chaikoff, 1956;Burns, 1957) as well as L-gulonic acid into Lxylulose (Touster et al 1955;Ishikawa & Noguchi, 1957). As stated before, it has also been observed to contain the necessary gulonolactonase converting L-gulonate into the corresponding lactone.…”

Preparation of Azobenzenealkanethiols for Self-Assembled Monolayers with Photoswitchable Properties

“…NMR and TLC proved that no reaction between these compounds takes place, thus suggesting the compatibility of these two functionalities in one molecule. As the coupling reaction between nitroso benzenes and anilines is best performed in acetic acid, [34][35][36][37][38][39][40] the compatibility of the aliphatic thioester and the aniline was also tested in this solvent without and with addition of 4-methylnitrosobenzene: the thioester was not altered in either case and the formation of the azobenzene proceeded cleanly both at room temperature and when heated to reflux. With these positive results, we were confident enough to pursue the synthesis of the two node compounds 1a, b.…”

“…The azobenzene unit should be formed from an amino group already present in the node compounds by reaction with a variety of nitroso benzenes. [18,[34][35][36][37][38][39][40] The late introduction of the azobenzene group is also advantageous regarding the handling of the compounds, because azobenzenes are often sensitive to elevated temperatures, light, and many reagents.…”

A Survey on the Reactivity of Phenyliodonium Ylide of 2-Hydroxy-1,4-Naphthoquinone with Amino Compounds

“…The isolable products was 4-methyl-azobenzene ( 28 ) (in 7% yield), mp 70-71 ºC, lit. [ 11 ] mp 72 °C; 1 H-NMR (CDCl 3 ): δ 7.90 (d, J=7.9 Hz, 2H), 7.81 (d, J=7.9 Hz, 2H), 7.54-7.43 (m, 3H), 7.31 (d, J=7.9 Hz, 2H), 2.43 (s, 3H); MS m/z 196, (M + , 88), 119 (100).…”