Exchange reactions amino/hydrogen

GS-MS and H NMR analysis of the selectively deuteriated intermediate product 2-amino-5,2 -dichloro-3,4, 6 -trideuteriobenzophenone, 46, have shown that in the first acid-catalysed key exchange reaction one deuterium has been incorporated into the triply substituted A ring and two deuterium atoms into the doubly substituted aromatic ring B Hydrogens a , b and c have been deuteriated in 99%, 98% and 92%, respectively. 

Irradiation of tryptophan and related compounds is well known to result in hydrogen exchange at the 4-position of the indole nucleus and the side chain amino group is implicated In the process. This exchange reaction has now... 

C. The Enthalpy of Formation of Aniline and Amino/Hydrogen Exchange Reactions... 

For the sake of increased stability and improved storage, somewhat less reactive alternatives have been prepared from the labile chloroformate. For example, 2-(trimethylsilyl)ethyl -succinimidyl carbonate has been used to prepare Teoc-protected amino acids in water or dioxane using sodium hydrogen carbonate or triethylamine as the base. - 2-(Trimethylsilyl)ethyl 4-nitrophenyl carbo-nate2 246 g commercially available reagent (mp 34-36 C) that reacts with amino acids in a mixture of aqueous sodium hydroxide and rert-butyl alcohol or dioxane. Simple amines can be acylated with triethylamine under anhydrous conditions [Scheme 8.105]. Teoc derivatives can also be prepared by an exchange reaction using an aryl carbamate derivative and 2-(trimethylsilyl)ethanol as shown in Scheme 8.106. ... 

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