Diisopropylethylamine → HCID 178514926, compound

Participants

Reaction Steps

Lithium 3-((quinuclidin-4-ylmethylamino)methyl)-1H-indazole-4-carboxylate (3.9 g, 12.1 mmol) from Step B above in THF (20 mL) was cooled in an ice bath while N,N-diisopropylethylamine (9.4 g, 72.8 mmol) was added, followed by 1-propanephosphonic acid cyclic anhydride (T3P) (23.0 g, 72.8 mmol). The reaction mixture was stirred at room temperature for 5 h and then concentrated under reduced pressure. The crude material was purified by column chromatography (silica gel, 60:36:4 dichloromethane/methanol/concentrated ammonium hydroxide) to give 4-(quinuclidin-4-ylmethyl)-3,4-dihydropyrazolo[3,4,5-de]isoquinolin-5(1H)-one as a yellow oil (468 mg, 13%): 1H NMR (500 MHz, CD3OD) δ 7.62-7.60 (m, 1H), 7.54-7.53, (m, 2H), 5.15 (s, 2H), 3.53 (s, 2H), 2.93 (t, J=8.0 Hz, 6H), 1.67 (t, J=8.0 Hz, 6H); MS (ESI+) m/z 297 (M+H).

Provenance & Evidence