1,8-Diazabicyclo(5.4.0)undec-7-ene → 3-[3-cyclopropyl-2-(4-methoxy-phenyl)-3H-imidazol-4-yl]-2-methyl-acrylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

3-cyclopropyl-2-(4-methoxy-phenyl)-3H-imidazole-4-carbaldehyde (475 mg, 1.96 mmol), triethyl-2-phosphonopropionate (0.63 ml, 2.94 mmol) and DBU (0.44 ml, 2.94 mmol) were dissolved in acetonitrile (5 ml). After stirring at 78° C. o.n. the reaction mixture was cooled to r.t., diluted with water (50 ml) and extracted with DCM. The combined organic phase was dried (Na2SO4), filtered and concentrated, to yield 3-[3-cyclopropyl-2-(4-methoxy-phenyl)-3H-imidazol-4-yl]-2-methyl-acrylic acid ethyl ester, which was dissolved in ethanol and hydrogenated at atmospheric pressure over 10% Pd/C (0.5 g) for 24 h. The reaction mixture was filtered through a celite pad and concentrated. After purification on silica gel (EA/DCM=1/1) the isolated product was dissolved in Et2O (10 ml) and treated with HCl (1N in Et2O, 4 ml). The resulting mixture was concentrated and the isolated residue was triturated with Et2O to isolate the title compound solid (466 mg). 1H-NMR: 7.90 (d, 2H), 7.10 (m, 3H), 4.16 (m, 2H), 3.90 (s, 3H), 3.47 (m, 1H), 3.24 (m, 1H), 2.85 (m, 2H), 1.37 (d, 3H), 1.27 (m, 5H), 0.75 (m, 2H).

Provenance & Evidence