Acetic Acid → (5,7-Dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)methanol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a 10 L reactor was charged HOAc (4.7 L), 2,4-Pentanedione (543 mL, 5.29 mol), and the glycolate salt of (5-amino-1H-1,2,4-triazol-3-yl)methanol (944 g, 4.96 mol). The mixture was heated to 100° C. until the solution was homogeneous. After reaching 100° C., the solution should be nearly homogeneous. The time at 100° C. should be ˜15–30 min. After this time, if the solution remains cloudy heating should be discontinued. The resulting solution was cooled to ambient temperature, and MTBE (16 L) was added and the mixture stirred for 30 min. The mixture was filtered through a 14″ Buchner, rinsed with MTBE (7 L), and dried in a vacuum oven overnight at 50° C. to provide 518 g (59%) of (5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)methanol as a white solid. The filtrate contained significant product, so a second crop was isolated by charging the MTBE filtrates to a 22 L reactor and cooling to 0° C. MTBE (8 L) was added and stirred for 2 hours. The resulting slurry was filtered and dried to yield an additional 173.7 g (20%) of (5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)methanol as a grey solid. Both crops were carried forward. 1H NMR (300 MHz, d6-DMSO): 2.57 (s, 3), 2.71 (d, 3, J=0.8), 4.63 (uneven d, 2, J=5.7), 5.49 (t, 1, J=6.2), 7.13 (d, 1, J=0.8).

Herkunft & Nachweise