Oxalyl chloride → 3-Benzyl-5-tert-butyl-7-chloro-triazolo[4,5-d]pyrimidine

Participants

Reaction Conditions

Reaction Steps

DMF over MS(105 g, 110 ml, 1.43 mol, Eq: 2.56) was charged in the reactor followed by Dichlormethane (1.46 kg, 1.1 l). The solution was heated to 35° C. and oxalylchloride (144 g, 97.6 ml, 1.11 mol, Eq: 2) was added over 1 h. After 45 min, a fine suspension of 3-benzyl-5-tert-butyl-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7(4H)-one (161 g, 557 mmol, Eq: 1.00) in a mixture of dichlormethane (877 g, 662 ml) and DMF (41.8 g, 44.1 ml) was added over of 20 min. After 3 h, the reaction mixture was cooled to RT and slowly added to a cold (0-5° C.) half saturated aqueous NaHCO3 (1.76 l). The organic phase was separated and washed again with half saturated NaHCO3 (662 ml) followed by water (662 g, 662 ml). Then the org. phase was dried over MgSO4 and was concentrated under reduced pressure at 50° C./down to 10 mbar to give 192 g of a crude oil which does crystallize on standing. The crude 3-benzyl-5-tert-butyl-7-chloro-triazolo[4,5-d]pyrimidine was introduced in the next step without further purification.

Provenance & Evidence