Methylhydrazine → HCID 19607529, compound

Participants

Reaction Steps

4.53 mL (0.085 mol) of methyl hydrazine (purchased from Aldrich Chemical Company) was added dropwise to a mixture of 21.54 g (0.066 mol) of the title compound of Step D in 115 mL of ethanol. The mixture was stirred at reflux under nitrogen for 5 hr and was then evaporated to dryness. The crude product was chromatographed over silica gel eluting with a mixture of (1:9) ethyl acetate:hexane to yield two components. Concentration of the major fraction yielded 14.72 g of the title compound of Step E as an oil; 1H NMR (CDCl3): δ2.3 (s,3H), 2.82 (s,3H), 3.76 (s,2H), 3.9 (s,3H), 7.2 (s, 1H), 7.3 (s,1H). Concentration of the minor fraction yielded 3.87 g of the isomer 8-bromo-1,4-dihydro-1,6,9-trimethyl[1]benzothiopyrano[4,3-c]pyrazole as an oil; 1H NMR (CDCl3): δ2.3 (s,3H), 2.46 (s,3H), 3.75 (s,3H), 3.59 and 3.81 (2d,2H), 7.4 (s,1H), 7.45 (s,1H).

Provenance & Evidence