Hydrogen selenide sulfide, sodium

Sodium hydrogen carbonate, 457 Sodium hydrogen selenide, 459 Sodium hydrogen telluride, 459-460 Sodium hydrosulfite, 252 Sodium hydroxide, 460-461 Sodium methoxide, 463 Sodium p-methoxythiophenoxide, 421 Sodium 2-mcthyl-2-butoxide, 339 Sodium naphthalenide, 464 Sodium nitronates, 370, 371 Sodium selenophenolate, 212, 307, 397 Sodium sulfide, 360 Sodium tetracarbonylhydridoferrate, 419-420... 

Compounds Selenium dioxide selenium trioxide selenium oxychloride sodium selenite sodium selenate hydrogen selenide selenic acid selenium sulfide selenium disulfide... 

A large number of 3-pyrazolin-5-thiones and a few 5-seleno analogs (Table XVIII) have been prepared. Almost all of these have been synthesized by reaction of the methochloride or methiodide of a 3- or 5-halogenated pyrazole with potassium hydrogen sulfide,844,984,986,988,992 potassium sulfide, sodium sulfide901 or potassium hydrogen selenide.986 This method of synthesis is illustrated in eq. 149 for a 5-halopyrazole. 

Formylation of Aromatic Rings. The Vilsmeier reagent attacks electron-rich aromatic systems to form aryl-methyleneiminium ions which liberate a formylated aromatic compound upon hydrolysis (eq 2). Thio- and selenoaldehydes can be prepared by hydrolysis in the presence of Sodium Hydrogen Sulfide or Sodium Hydrogen Selenide. A wide range of aromatic systems can be formylated in this fashion, including benzene derivatives, polyaromatic hydrocarbons (eq 3), and azulene. Substitution occurs at relatively electron-rich positions. 

Using the periodic table if necessary, write formulas for the following compounds (a) hydrogen bromide, (b) magnesium chloride, (c) barium sulfide, (d) aluminum fluoride, (e) beryllium bromide, (/) barium selenide, and (g) sodium iodide. 

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