N-Benzylethylenediamine → N-(6-Cyano-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-yl)-N'-benzylethylenediamine

Participants

Reaction Steps

A solution of 4-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran (1.50 g, 5.64 mmole, from Example 8, part B) and N-benzylethylenediamine (8.48 g, 10 eq.) containing NaHCO3 (4.80 g, 5 eq.) in N,N-dimethylformamide (30 ml) was stirred for 48 hours at room temperature. The reaction mixture was partitioned between ethyl acetate and distilled H2O. The organic phase was washed with distilled H2O, saturated NaCl solution, dried over Na2SO4 and evaporated in vacuo to obtain 4.10 g of an orange oil. The crude product was chromatographed on silica eluting with 9:1 methylene chloride/methanol (trace of NH4OH) to obtain 0.91 g (48%) of the title compound as a colorless gum. 1H NMR (CDCl3) δ 8.00 (s, 1H). 7.49-7.34 (m, 6H), 6.88 (d, J=8.80 Hz, 1H), 3.93-3.82 (m, 3H), 3.03-2.80 (m, 5H), 2.25 (dd, J=5.57 and 13.20 Hz, 1H), 1.67 (m, 1H), 1.53 (s, 3H), 1.35 (s, 3H); 13C NMR (CDCl3) δ 157.66, 139.89, 132.52, 132.03, 128.43, 128.14, 127.05, 125.55, 119.65, 118.06, 102.89, 76.86, 53.73, 49.38, 49.01, 45.32, 39.25, 36.40, 29.72, 25.02; MS: (M+H)+ @334.

Provenance & Evidence