Reagents and yields

The A -oxidation of diazafluorenes and -fluorenones has been studied by Mlochowski and coworkers <79CJC1506>. The 1,8- and 2,5-diazafluorenones yielded bis N-oxides with H202/acetic acid whereas the 1,5- and 4,5 isomers gave tars. H202/Na2W05 proved to be a milder reagent and yielded oxides of all isomers. Because of the readily oxidized 9-position, diazafluorenes yielded only the N-oxides of the corresponding fluorenones. 

All three chlorines may be replaced by using excess of reagent and yields are usually high. Other alcohols such as isopropyl alcohol, allyl alcohol, and 2-methoxyethanol may be used. 

Tapia et al. [23] described the use of nitric acid supported on silica gel for the mono-nitration of activated aromatic compounds such as phenols and aryl methyl ethers. Riego et al. [24] used sulfuric acid supported on silica gel for the mononitration of a variety of aromatic compounds. The reaction was performed at ambient temperature with 70 % nitric acid or isopropyl nitrate as reagents and yielded mono-nitrated products within short reaction periods. Toluene was quantitatively converted to NT in 0.1 h, without a solvent, by use of a catalyst containing 10 mmol g as supported 70% H2SO4. A comparative study of the reaction kinetics of the nitration using supported and unsupported liquid acids revealed that the performance of supported sulfuric acid is comparable with that of 90 % sulfuric acid in the classical liquid phase reaction where complete protonation of nitric acid occurs [25]. 

Some commercial sulfonations and sulfations employ nearly stoichiometric quantities of reagents and yield products which can be neutralized and used directly as is, or with minor purification. These include benzene, toluene, and xylenesulfonic acids as prepared by the partial-pressure distillation method dodecylbenzene sulfonated with SO3 long-chain alcohol sulfates prepared with ClSQjH, SOs, or NHjSOiH some sulfonated aromatic amines as prepared by the baking process and products from certain sulfoalkylation or sulfite reactions (see technical section for detailed examples). In other cases, even when excess acid is present, it is neutralized with the sulfonate since sodium sulfate is desired or allowable in the final product. Examples include dodecylbenzene sulfonated with oleum and lauryl alcohol sulfated with concentrated acid. In most cases, however, separation or purification is necessary. The three most common procedures may be summarized as follows ... 

The nitroso function is unique in that it can stabilize both a positive and a negative charge on the a-carbon atom. Consequently, N-nitrosoenamines of the type (13) are alkylated by both electrophilic and nucleophilic reagents, and yield secondary amines on subsequent denitrosation. ... 

During the 2007-2008 acaderttic year, we intend to pilot a ferrofluid lab in several sections of the first semester general cherrristry laboratory 30). The procedure will be rewritten to emphasize stoichiometric concepts inclnding limiting reagent and yield. Eventnally, we anticipate nsing this lab in all first semester sectiorrs and the modified version of the Color My Nanoworld (77) in all second semester sections. 

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