Urea → 1-Methyl-1H-pyrazolo[4,3-b]pyridine

Participants

Reaction Steps

In analogy to GP 4b, 3-amino-5-tert-butylisoxazole (88.45 mg, 0.63 mmol, 1.23 eq.) was treated with triphosgene (59.44 mg, 0.2 mmol, 0.4 eq.) and Intermediate 3.1 (200 mg, 0.5 mmol, 1 eq.) in 10 mL acetonitril. The crude urea was subsequently cyclized with 48 μL methylhydrazine (0.91 mmol, 1.8 eq.) in 10 mL 1-PrOH to yield 80 mg of the N1-methyl-pyrazolopyridine (0.15 mmol, 30% yield over 2 steps).

Provenance & Evidence