Hydrochloric Acid → (1aR,5aR)-2-(4-iodo-pyridin-2-yl)-1a,2,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of (1R,5S)-bicyclo[3.1.0]hexan-2-one (2.045 g, 21.27 mmol) and diethyl oxalate (2.91 mL, 21.27 mmol) in absolute ethanol (100 mL) was added a 1.0 M THF solution of potassium 2-methylpropan-2-olate (21.27 mL, 21.27 mmol). The mixture was stirred at 40° C. for 4 h. 2-Hydrazinyl-4-iodopyridine (5.00 g, 21.27 mmol) was added followed by a 3.0 M aqueous solution of hydrogen chloride (21.27 mL, 63.8 mmol). The reaction was stirred at 45° C., for 16 h. Brine (150 mL) was added. The mixture was extracted with dichloromethane (3×50 mL). The combined organic extracts were washed with brine (100 mL), dried (MgSO4), filtered, and then concentrated. The residue was purified by silica gel flash chromatography to give the title compound (5.8 g) as a white solid. LCMS m/z=396.1 [M+H]+; 1H NMR (400 MHz, CDCl3) δ 0.44 (td, J=4.7, 3.5 Hz, 1H), 1.25 (td, J=8.0, 5.1 Hz, 1H), 1.40 (t, J=7.1 Hz, 3H), 2.22-2.29 (m, 1H), 2.80-2.85 (m, 1H), 2.85 (d, J=17.1 Hz, 1H), 2.97 (dd, J=16.9, 6.6 Hz, 1H), 4.39 (q, J=7.1 Hz, 2H), 7.57 (dd, J=5.2, 1.4 Hz, 1H), 8.10 (d, J=5.2 Hz, 1H), 8.48 (s, 1H).

Provenance & Evidence