p-Toluenesulfonic acid → 2,3-Dihydroperimidine

Participants

Reaction Steps

The above aldehyde (1.47 g, 4 mmol) was treated with N,N'-dimethyl-1,8-diaminonaphthalene (4.2 mmol), and para-toluenesulfonic acid (5 mg) in tetrahydrofuran (15 mL) for 20 min at room temperature. The solution was diluted with ether, washed with dilute sodium carbonate, and concentrated. The residue was recrystallized from hexane-ethyl acetate to give the 2,3-dihydroperimidine 7 (1.22 g, 59%): mp 89-90° C.; NMR 7.5-6.75(m, 12H), 6.34(d, 2H), 4.24(t, 1H), 3.9(2t, 4H), 3.02(s, 6H), 1.8-1.2(m, 16H), 0.85(t, 3H).

Provenance & Evidence