Formaldehyde → Exemestane EP Impurity B

Participants

Reaction Steps

The resulting 1,3-dipyrrolidinoandrosta-3,5-diene-17one is then mixed in amount of 1 equivalent, with 2.6 equivalents formalin (formaldehyde) in 10 ml dichloromethane/g at room temperature. The reaction mixture is then acidified to a pH of about 2 with 2% sulfuric acid solution. Accordingly, an organic layer is formed, which is washed with 2% sulfuric acid and 1:1 water/brine. Solvent exchange into toluene (approximately 10 ml/g) is then carried out wherein the product crystallizes as toluene exchange traspires. Said product is collected washed and dried to provide 6-hydroxymethyl-androsta-1,4-diene-3,17 dione. One of ordinary skill in the art can further modify the stereochemistry at position 6, if so desired by employing known techniques in the art.

Provenance & Evidence