Beta-Phenoxypropionic Acid and Some of Its Derivatives. Chromanone

Synthesis of heterocyclic compounds by the reactions of exocyclic α,β‐unsaturated ketones

“…41 (4), -1-thiochromanones (5),-flavanones (6) and -1-thioflavanones (7) were prepared by the reaction of chromanone, 1-thiochromanone, flavanone and 1-thioflavanone with the appropriate aromatic aldehydes (Scheme 2). In many cases acid-catalyzed condensation of the cyclic ketone and aldehyde components have been performed [27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Inorg a n i c bases have also been used as catalysts for this purpose [47][48][49].…”

“…Formation of various pyrazoline isomers (26)(27)(28)(29) has been supposed (Scheme 12). Since no spectroscopic data are included in their papers, the structure elucidation of the products remained questionable.…”

Some characteristics of deposits on a commercially aged, gas-oil hydrotreating catalyst

“…It has been established that FeS undergoes rapid oxidation in the vicinity of 500 °C to Fe203 and S or S02 depending on the available oxygen. 4FeS + 302 -2Fe203 + 4S 2FeS + 3.502 -* Fe203 + 2S02 Some years ago, Powell (1923) made interesting observations on the cooling of coke-oven coke. When quenched rapidly, the FeS content remained unchanged, but when cooled slowly, the FeS was converted to Fe203 even when access of air was limited.…”

Sulfur Compounds in Coal

“…Most of the conclusions of the classic work of Powell (1920Powell ( , 1923 are still valid. Coked coal releases hydrogen sulfide as well as other volatile sulfur compounds.…”