Phosphorus oxychloride → 3-Benzenesulphonyl-7-chloro-5-(4-methyl-piperazin-1-ylmethyl)-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidine

Participants

Reaction Steps

A suspension of 4.0 g (9 mmol) of 3-benzenesulphonyl-5-(4-methyl-piperazin-1-ylmethyl)-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidin-7-ol in 100 ml of POCl3 was heated at reflux for 3 hrs. The reaction solution was cooled to RT and evaporated. The residue was treated with 100 ml of ice-water and the pH value of the solution was adjusted to 8 with sat. NaHCO3 solution. The aqueous phase was extracted three times with 150 ml of CH2Cl2 and the organic phases were dried (MgSO4), filtered and evaporated. Chroma-tography (SiO2CH2Cl2/MeOH 10:1) of the residue yielded 4.0 g (98%) of 3-benzenesulphonyl-7-chloro-5-(4-methyl-piperazin-1-ylmethyl)-2-methylsulphanyl-pyrazolo[1,5-a]pyrimidine as a pale brown powder, m.p. 113-116°.

Provenance & Evidence