Benzylhydrazine dihydrochloride → 1-benzyl-3-methyl-4-nitroso-5-phenyl-1H-pyrazole

Participants

Reaction Steps

To a 0° C. solution of 2.32 g of 1-phenyl-butane-1,2,3-trione 2-oxime in 31 mL of EtOH was added a suspension of 2.43 g benzyl hydrazine dihydrochloride in 9 mL EtOH. The reaction mixture was warmed to rt and stirred for 96 h. The reaction mixture was concentrated under reduced pressure and purified by means of MPLC (120 g SiO2, 45% EtOAc:Heptane) to obtain 1-benzyl-3-methyl-4-nitroso-5-phenyl-1H-pyrazole. A suspension of 2.55 g 1-benzyl-3-methyl-4-nitroso-5-phenyl-1H-pyrazole, 34 mL EtOAc and 500 mg 10% Pd/C was reacted under 40 psi H2 atmosphere using a Parr apparatus. After 4 h, the suspension was filtered through Celite (EtOH eluting) and the filtrate was concentrated under reduced pressure and purified by means of MPLC (120 g SiO2, 60% EtOAc:Heptane) to give the title compound as an orange oil.

Provenance & Evidence