Hydrochloric Acid → HCID 17871365, compound

Participants

Reaction Steps

A solution of Cs2CO3 (3.26 g) in H2O (2 mL) was diluted with MeOH (8 mL) and ester 10 (0.91 g, 3.2 mmol) was added. The mixture was heated under reflux for 2.5 h then cooled and acidified with 0.5N HCl. The precipitated solid was collected, dried and dissolved in warm EtOAc. The solution was concentrated to a small volume under reduced pressure below 40° C. and then diluted with i-Pr2O to provide (E) -3- (1-methylpyrrole-2-carboxamido)cinnamic acid (11) (0.79 g, 91%) mp 202-204° C. 1H NMR [(CD3)2SO] δ12.44 (br s, 1 H, CO2H), 9.82 (s, 1 H, NH), 7.99 (s, 1 H, H-2), 7.79-7.73 (m, 1 H, H-4), 7.56 (d, J=16.0 Hz, 1 H, PhCH═CH), 7.40-7.34 (m, 2 H, H-5,6), 7.05 (dd, J=4.0, 1.7 Hz, 1 H, H-pyrrole), 7.02 (t, J=2.0 Hz, 1 H, H-pyrrole), 6.44 (d, J=16.0 Hz, 1 H, PhCH═CH), 6.11 (dd, J=3.8,2.6 Hz, 1 H, H-pyrrole), 3.89 (s, 3 H, NCH3).

Provenance & Evidence