Diisopropylamine → HCID 52951681, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of anhydrous diisopropylamine (18.5 mL, 0.13 mol) in anhydrous tetrahydrofuran (160 mL) was added dropwise at −80° C., under argon, a 1.3 M n-butyllithium solution in hexane (100 mL, 0.13 mol). The mixture was stirred at −80° C. for 1 h before addition dropwise of a solution of 2-fluoro-4-picoline (41) (9.00 g, 6.30 mmol) in anhydrous tetrahydrofuran (60 mL). The mixture was stirred at −80° C. for 1 h once again before addition dropwise of a p-formaldehyde (16.6 g, 0.55 mol) suspension in anhydrous tetrahydrofuran (100 mL). The mixture was stirred at −80° C. for 1 h and then at room temperature for 12 h. A saturated aqueous ammonium chloride solution (450 mL) was added to the mixture. The solution was decanted and the aqueous layer was extracted with dichloromethane (4×200 mL). The organic layers were combined, dried on magnesium sulfate, filtered and evaporated under vacuum. The residue obtained was chromatographed (Al2O3, CH2Cl2/EtOH, 99/1, v/v) to give compound 42 (7.25 g, 51.4 mmol) as an orange-coloured oil. Yield 57%; Rf (Al2O3, CH2Cl2/EtOH, 99/1, v/v) 0.32; IR (CCl4) ν 1046, 1149, 1278, 1413, 1613, 2800-3000, 3100-3600, 3634 cm−1; 1H NMR (200 MHz, CDCl3) δ 2.87 (t, 2H, J=6.3 Hz), 3.87 (t, 2H, J=6.3 Hz), 6.82 (s, 1H), 7.07 (d, 1H, J=5.2 Hz), 8.01 (d, 1H, J=5.2 Hz); MS m/z 141 (M+, 23), 111 (100), 91 (34), 83 (14), 64 (10), 57 (12).

Provenance & Evidence