2,4,6-TRIISOPROPYLBENZENESULFONYL HYDRAZIDE

White crystal

2,4,6-Triisopropylbenzenesulfonyl hydrazide (TPSH) is a best source of diazene. It can be used as a selective reducing agent for the reduction of alkenes and other double bonds via in situ formation of diazene (diimide) in the presence of base. TPSH reduction method is efficiently used in the synthesis of polymers and natural products as it tolerates sensitive groups such as esters, ketones, or organometal complexes. It also undergoes condensation reaction with ketones and aldehydes to produce corresponding hydrazones that can be converted into reactive intermediates such as diazoalkanes, carbenes, carbenium ions, and alkyllithiums.
It can be used as a reagent to synthesize:

• Nitrogen-containing polycyclic compounds by intramolecular cyclopropanation of N-alkyl indoles/pyrroles.
• Vinyl sulfones by sulfonylation reaction of vinyl bromides.
• Nitrile derivatives from carbonyl compounds via formation of corresponding hydrazones.

As a reagent for generation of diimide

2,4,6-Triisopropylbenzenesulfonyl hydrazide is used as a diazene equivalent; condensed with ketones and aldehydes to form hydrazones that can be converted into reactive  intermediates such as diazoalkanes, carbenes, carbenium ions, alkyllithiums, or umpolung synthons.

2,4,6-Triisopropylbenzenesulfonyl hydrazide may be prepared in 96% yield by treating commercially available 2,4,6-triisopropylbenzenesulfonyl  chloride with hydrazine hydrate in THF, being careful to keep the reaction and workup temperatures below or around 0 °C. The  solid can be dried in vacuo over P2O5 for 24 h.