Hydrazine hydrate (1:1) → 4-Amino-2-methyl-2,3-dihydropyridazin-3-one

Participants

Reaction Conditions

Reaction Steps

9.14 g (52 mmoles) of intermediate 4b are placed in mL hydrazine monohydrate. The reaction medium is agitated for 3 h at 80° C. then diluted in 100 mL water and extracted with CH2Cl2 then with AcOEt. After drying over Na2SO4, the organic phases are evaporated and the residue obtained is purified by silica gel flash chromatography (CH2Cl2—AcOEt, gradient 100:0 to 0:100 over 50 min). 4.17 g of intermediate 4c are thus obtained in the form of an orange-like solid (yield 63%). TLC silica 60 F 254 Merck, CH2Cl2—AcOEt: 50:50, Rf=0.16.

Provenance & Evidence