Potassium tert-butoxide → HCID 178419785, compound

Participants

Reaction Steps

Air was bubbled through a stirring solution of 2-benzyl-4-(2H-tetrazol-5-yl)-1a,2,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene (10.4 g, 37.4 mmol) and KOt-Bu (374 mL of a 1M solution in THF, 374 mmol) in DMSO (300 mL) for 20 h at rt. The remaining THF was removed in vacuo and the reaction was acidified to pH=2 by the addition of HCl (3M aq). The mixture was concentrated in vacuo to near dryness. The residue was dissolved in HCl (1N aq., 250 mL) and extracted with EtOAc (5×250 mL). The organics were dried over MgSO4, filtered, and concentrated. The product was purified and converted to the ammonium salt by loading material (as a solution in MeOH) on to a column containing Bondesil SCX SPE resin (˜250 g). The column was flushed with MeOH (200 mL) to remove unbound impurities. The product was eluted using 2N NH3/MeOH (approx. 200 mL). Concentration of the basic eluant yielded the ammonium salt of Compound 4 as a white solid. 1H NMR (400 MHz, MeOD): δ 3.02 (1H, dd, J=16.4, 6.0 Hz), 2.90 (1H, d, J=16.0 Hz), 2.19 (2H, m), 1.17 (1H, m), 0.33 (1H, m). HPLC/MS: Discovery® C18 column (5μ, 50×2.1 mm), 5% v/v CH3CN (containing 1% v/v TFA) in H2O (containing 1% v/v TFA) gradient to 99% v/v CH3CN in H2O, 0.75 mL/min, tr=1.21 min, ESI+=189.0 (M+H). [α]25D+35.7 (c 0.39, MeOH).

Provenance & Evidence