Acidity continued nitromethane

Nitromethane. 103 cc of 40% sodium hydroxide solution is added, slowly with stirring, to a mixture of 100 g of chloroacetic acid and 100 g of crushed ice until the mixture is just barely alkaline to phenolphthalein. Keep the temp between 10-20° during this addition. 73 g of sodium nitrite in 100 cc of water is added and the whole is heated in a 500 cc flask, rigged to a distillation apparatus that has the thermometer immersed in the liquid. Distillation of nitromethane starts at about 87° and continues to come over to 108-110°, which is where the temp is maintained for 30 min. Nitromethane is separated from the aqueous layer of the distillate in a separation funnel and is distilled three more times, being separated from the aqueous layer after each distillation. The nitro is then dried over calcium chloride and distilled again, collecting the fraction boiling at 98-101°. Yield 27 g. 

The thermoplastics were investigated by CIGC well below their glass transitions so that surface thermodynamics were dominant. Column temperatures were varied over a 40C range in order to find enthalpies and entropies of interaction. When injected into the capillary columns coated with the thermoplastic polymers, the three probes listed above exhibited peaks which tailed continuously even at the lowest possible concentrations. For this reason, weaker acids and bases which eluted as symmetric peaks were used to study the polymer surfaces. Specifically, methylene chloride (CH Cl.) with an AN of 20.4 and its DN is equal to 0, and nitromethane TNO -CH ) having an AN equal to 20.5 and DN equal to 2.7 were chosen. These chemicals were gold-label grade from Aldrich Chemical and stored over 4 A molecular sieves before use. 

Such reactions are normally base catalyzed. Scheme 76 illustrates the use of this reaction to provide both fused and bridged rings. Other techniques for synthesizing the keto ester from trimethylsilyl ethers are shown in Scheme 77. The diketones shown were usually isolated as a mixture of enols or enol ethers. Acid-catalyzed acylation also provides a route to diketones not readily obtained by other routes (Scheme 78). The acid catalysts included polyphosphoric acid and naphthalene-2-sulfonic acid. In the latter example continuous removal of water facilitated the reaction. A related reaction involved treatment of an acid chloride with silver perchlorate in nitromethane (equation 41), although the yield of diketone was low. ° ... 

A detailed analytical study of fhe acfivity of some solid acid catalysts, including mesoporous silica-supported Nation, in the acylation of anisole with AAN allows the conclusion that catalyst deactivation is caused by the primary ketone product and/or multiple acetylated products in the micropores of Nation catalyst aggregates. i Experiments were performed with a commercially available silica-supported Nation catalyst in a continuous-mode slurry operation by using carbon-dioxide-expanded liquids (nitromethane or nitrobenzene) as solvents. At 90°C, 80% AAN conversion is observed with a TOS of 2 h, but the catalyst rapidly deactivates, and 27% conversion is evaluated after 6 h TOS with a TON value of about 400. The catalyst can, however, be completely regenerated upon nitric acid treatment. These results confirm that silica-supported Nation catalysts are promising alternatives for the traditional aluminum chloride homogeneous Lewis acid catalyst. 

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