title: Single-step, quantitative derivatization of amino, carboxyl, and hydroxyl groups in iodothyronine amino acids with ethanolic pivalic anhydride containing 4-dimethylaminopyridine.
abstract: Reaction of thyroxine with ethanol and pivalic anhydride in the presence of 4-dimethylaminopyridine quantitatively forms N,O-dipivalyl thyroxine ethyl ester. Other iodothyronines react similarly and the procedure is moisture insensitive. Apparently this reaction is successful, in contrast to similar procedures reported for the derivatization of alpha-amino acids, because it overcomes the problem in other procedures of irreversible side reactions arising from an oxazolone intermediate.
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000631:Aminopyridines; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004104:Diiodothyronines / Q000302:isolation & purification*; D000431:Ethanol; D010421:Pentanoic Acids; D013970:Thyronines / Q000302:isolation & purification*; D013974:Thyroxine / Q000302:isolation & purification; D014284:Triiodothyronine / Q000031:analogs & derivatives* / Q000302:isolation & purification
chemical_list: D000631:Aminopyridines; D004104:Diiodothyronines; D010421:Pentanoic Acids; D013970:Thyronines; D014284:Triiodothyronine; C048464:pivalic anhydride; D000431:Ethanol; D015761:4-Aminopyridine; C003885:4-dimethylaminopyridine; D013974:Thyroxine