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

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.

1. custom2 hr
2. concentrationThe solution was concentrated in vacuo
3. temperaturewithout heating
4. additionTo the reduced volume solution was added EtOAc
5. washthe solution washed with a sat NaHCO3 solution
6. concentrationconcentrated in vacuo
7. temperaturewithout heating
8. filtrationFiltration
9. concentrationover a small silica gel plug (2:1 EtOAc:Hex) and concentration

ORD record

ord-259b631434fb4556b10bed0845f93446

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08129371B2