1-Methyl-4-iodo-1H-pyrazole → di-tert-butyl 1-(1-methyl-1H-pyrazol-4-yl)hydrazine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-iodo-1-methyl-1H-pyrazole (21 g, 0.12 mol) in dry ether (200 mL) at −78° C. was added n-BuLi (84.5 mL of a 2.5 M solution in hexane, 0.18 mol) over a period of 30 min and the mixture stirred for a further 30 min. A solution of di-tert-butyl(Z)-diazene-1,2-dicarboxylate (30.4 g, 0.12 mol) in ether (100 ml) was added to the reaction mixture over a period of 10 min and the resultant mixture stirred at −78° C. for 1 hour. The reaction was warmed to 0° C. and quenched with ice-water and extracted with ether (3×100 mL). The organic layer was separated, dried (Na2SO4) and evaporated in vacuo. The crude material was washed with hexane and then dried under vacuum to give the title compound in 30% yield, 11.2 g.

Provenance & Evidence