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SUNY-CortlandCortland. NY 13045 Editor's Note: One of the greatest deterrents to the adoption of microscale techniques for organic chemistry laboratory courses in many institutions is the high cost of microscale glassware. There are many experiments that can be carried out on a small scale using regular glassware as the following experiment demonstrates. Information about other experiments that meet these criteria would be appreciated and should be sent to the editor of this column.

Abtract: Nitrogen-and nitrous oxide-separated carbocationarboxylate ion pairs have been prepared by five different reactions: the rearrangement of N-nitroso amides, the reaction of acid chlorides with anti-diazoates, the reaction of acid chlorides with syn-diazoates, the reaction of acid chlorides with anions of N-nitroamines, and the decomposition of N-nitroso-0-acylhydroxylamines. Comparative stereochemical, I 8 0 scrambling, and product analyses have been made where common alkyl groups (1-phenylethyl), acyl groups (Znaphthoyl), solvent, and temperature are employed. The five reactions yield the same organic products, and they p r d with the same degree of retention of configuration; the reactions that were examined show the same extent of I8O scrambling. Interestingly, differences in product ratios were detected in a comparison of the nitroso amide and nitrosohydroxylamine reactions, with the latter reaction providing the larger proportion of ester. The results indicate that the structural differences built into the precursor molecules are averaged out with respect to two of the product characteristics, but not to all three. These reactions are proposed to proceed via nitrogen-or nitrous oxide-separated ion pairs. The reactions are little influenced by variables such as temperature and solvent, and the carbocations prepared in this manner exhibit a remarkably high reactivity. The relevance of these results to other methods of deamination is examined. Solvolytic (SN1)2 and deamination3s4 reactions proceed formally through carbocation intermediates, but the kind and distribution of products in the two casts can differn5 For example, the nitrous acid deamination of propylamine in acetic acid yields propyl acetate (60%) and isopropyl acetate (40%), whereas the solvolysis of propyl 4-toluenesulfonate in the same solvent yields only 2.8% of the secondary Deamination reactions can be adapted to nonpolar solvents, and under these conditions the carbocations formed can be trapped by the solvent (if certain conditions are met); they also exhibit remarkable reactivity (eqs 1 and 2).6a9738 C~H S C H~N ( N O ) S O~C F~--C~H~C H : N~ O~S C F~-~C O H S C H $ -CCHI ( 2 ) CeHsCHiCoHsWe now report on reactions designed to reveal the properties of intermediates in deamination reactions. We have examined a set of reactions utilizing chiral and '*O-labeled reactants in which different but related intermediates are formed (Chart I); we examined the N-nitroso amide decomposition, a modification of the nitrous acid approach, and four variants in the same solvent and at the same temperature. The reactions produce carbocations and carboxylate ions in common, but they differ in the inert molecule produced (N2 vs N20) and in the spatial arrangements of the key elements in the precursors (reaction 1 (2) vs 3 and reaction 4 vs 5 in Chart I).Reaction 1, the N-nitroso amide decomposition (Chart I), has previously been examined in some depth.4aJ1J2 A rearrangement leads to the anti-diazoate ester (3); subsequent reactions lead to substitution...

The methyl and ethyl TVbutyl-TV-nitrocarbamates based on n-butylamine, secbutylamine, and tert-butylamine were decomposed in ethanol and in other solvents, and the product distributions were measured. These results and those from related nitrocarbamates are discussed in terms of inert gas-separated ion-pair intermediates that appear to be characteristic of deamination reactions. The product distributions indicate a gradual change in mechanism with carbonium ion stability; discontinuities as a function of the substituent were not seen. DiscussionProducts. The decomposition of methyl TV-nitrocarbamates 4a-c in inert solvents yields the corresponding carbonate esters, olefins, nitrous oxide, carbon dioxide, and methanol (Chart I, Table I).5a'6b In a reactive solvent such as ethanol, in addition to the above products (which constitute the intramolecular portion of the reaction), solvent-derived products are formed, namely the butyl ethyl ethers. Prolonged reaction times are required for the decomposition of the «-butyl derivatives (4a and 5a) and, in these cases, ester