185456-34-2Relevant articles and documents
Synthesis of substituted hydrazines from triprotected precursors
Maeeorg, Uno,Pehk, Tonis,Ragnarsson, Ulf
, p. 1127 - 1133 (2007/10/03)
Full details related to the preparation and application of two triprotected reagents, 1,2,2-Boc3-hydrazine (1) and 1,2-Boc2-2-Z-hydrazine (2), for stepwise synthesis of substituted hydrazines are presented. In the presence of base these compounds undergo substitution at N1, often accompanied by partial loss of protecting groups at N2. Optimized alkylation procedures, eliminating or greatly diminishing these side reactions, involving phase-transfer catalysis are reported. The initial products can be selectively deprotected at N2 to provide a new alkylation site. Twice alkylated derivatives of 1 and 2 differ in their potential to undergo further selective cleavage, and only the latter are capable of such. A limited number of partly protected substituted hydrazine derivatives have been made using the novel procedures. Compounds 1 and 2 both exist as mixtures of two conformers which have been assigned, whereas in alkylated derivatives up to four such are present. For two dialkylated compounds all conformers have also been assigned and their relative distribution experimentally determined. The results are in good agreement with those from theoretical calculations.
