Formaldehyde → HCID 135544114, compound

Participants

Reaction Steps

5-(5-Acetyl-2-butoxy-3-pyridinyl)-3-ethyl-2-(4-piperidinyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (Example 49) (100 mg, 0.23 mmol) was dissolved in dichloromethane (10 mL) and formaldehyde (27 mg, 0.01 mL of a 37-41% solution) was added. After 30 min stirring sodium triacetoxyborohydride (108 mg, 0.51 mmol) was added and stirring continued for 14 h. Further formaldehyde (0.01 mL of 37-41% solution) and sodium triacetoxyborohydride (108 mg, 0.51 mmol) were added and stirring continued for a further 4.5 h. Starting material still remained so further formaldehyde (0.01 mL of 37-41% solution) and sodium triacetoxyborohydride (108 mg, 0.51 mmol) were added and stirring continued for a further 18 h. The reaction mixture was diluted with dichloromethane, washed with sodium bicarbonate solution then brine, dried (MgSO4) and concentrated. Purification by flash column chromatography (elution with 94:6:0.6 dichloromethane/methanol/0.88 ammonia) gave the product (41 mg) as a white solid.

Provenance & Evidence