Chloroform → 7-Chloro-6-(2-chloroethyl)-5-methylpyrazolo[1,5-a]pyrimidine

Temperature

100 °C

To 5.30 g (27.46 mmol) of 6-(2-hydroxyethyl)-5-methylpyrazolo[1,5-a]pyrimidin-7(4H)-one were added 8.5 ml (d=0.726, 61.10 mmol) of triethylamine. While cooling with ice water and stirring under a nitrogen atmosphere, 8.5 ml (d=1.645, 91.19 mmol) of phosphorus oxychloride were added dropwise to the mixture over 2 minutes. The resultant mixture was then stirred for 1 hour in an oil bath heated to 100° C. Thereafter, the reaction mixture was cooled with ice water and dissolved in 100 ml of chloroform, and the solution was poured into 500 ml of ice water. After full shake of the resultant mixture, the chloroform layer was separated, and the water layer was further extracted with chloroform (100 ml×2), and the chloroform layers were put together. After the whole chloroform layer was dried over anhydrous sodium sulfate, the solvent was distilled off. The residue was subjected to column chromatography on silica gel (chloroform) to obtain 3.7 g (yield: 59.8%) of the intended product.

1. customAfter full shake of the resultant mixture, the chloroform layer was separated
2. extractionthe water layer was further extracted with chloroform (100 ml×2)
3. dry with materialAfter the whole chloroform layer was dried over anhydrous sodium sulfate
4. distillationthe solvent was distilled off

ORD record

ord-11cc4a29aa3f46d9b21acffb75f33114

Source dataset

uspto-grants-1999_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05942515