Hydrazides in
organic chemistry are a class of
organic compounds with the formula R−NR1−NR2R3 where R is
acyl (R'−C(=O)−),
sulfonyl (R'−S(=O)2−),
phosphoryl ((R'−)2P(=O)−),
phosphonyl ((R'−O−)2P(=O)−) and similar groups (
chalcogen analogs are included, for example
sulfur analogs called thiohydrazides),[1]R1, R2, R3 and R' are any groups (typically
hydrogen or
organyl).[2] Unlike
hydrazine and alkylhydrazines, hydrazides are nonbasic owing to the inductive influence of the acyl, sulfonyl, or phosphoryl substituent.
Sulfonyl hydrazides
A common sulfonyl hydrazide is
p-toluenesulfonyl hydrazide, a white air-stable solid. They are also widely used as organic reagents.
2,4,6-Triisopropylbenzenesulfonylhydrazide is a useful source of
diimide.[6]
Acyl hydrazides
Acylhydrazines are
derivatives of
carboxylic acids, although they are typically prepared by the reaction of esters with hydrazine:[8]
Use
An applied example is a synthesis of
sunitinib begins by mixing 5-fluoro
isatin slowly into
hydrazine hydrate.[9] After 4 hours at 110 °C, the indole ring structure has been broken into (2-amino-5-fluoro-phenyl)-acetic acid hydrazide with reduction of the ketone at the 3-position. Subsequent
annelation in strong acid creates the 1,3-dihydro-2-oxo indole structure required for the drug.
^Chamberlin, A. Richard; Sheppeck, James E.; Somoza, Alvaro (2008). "2,4,6-Triisopropylbenzenesulfonylhydrazide". Encyclopedia of Reagents for Organic Synthesis.
doi:
10.1002/047084289X.rt259.pub2.
ISBN978-0471936237.