Methylhydrazine → 4,6-dichloro-1-methyl-1H-pyrazolo(3,4-d)pyrimidine

Participants

Reaction Steps

To a solution of 2,4,6-trichloro-pyrimidine-5-carbaldehyde (3.7 g, 17.5 mmol) in EtOH (50 mL) cooled to −78° C. was added methyl hydrazine (0.93 mL, 17.5 mmol) and TEA (8 mL). The mixture was stirred for 30 minutes at −78 C then 2 hr at 0 C. The solution was concentrated in vacuo without heating. To the reduced volume solution was added EtOAc and the solution washed with a sat NaHCO3 solution and concentrated in vacuo without heating. Filtration over a small silica gel plug (2:1 EtOAc:Hex) and concentration afforded the desired product as a yellow solid. It should be noted that the reaction with aromatic hydrazine compounds can be conducted at 0° C.

Provenance & Evidence