Methanol → 2-Methoxy-5-methyl-6-oxo-5,6,7,8-tetrahydro-[1,5]naphthyridine-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

A 1.1 g (5.0 mmol) solution of 6-methoxy-1-methyl-7-vinyl-3,4-dihydro-1H-[1,5]naphthyridin-2-one in 50 ml of methylene chloride and 10 ml of methanol was cooled to −70° C. Ozone (via an ozone generator) was bubbled into the solution until a blue color was achieved. The reaction mixture was stirred at −70° C. for 30 minutes and quenched with 4.0 ml of dimethyl sulfide. The reaction mixture was stirred for 18 hours at room temperature. The reaction mixture was poured into 50 ml of water. The organic layer was dried (Na2SO4) and evaporated. This residue was chromatographed on silica using 10:1 chloroform/ethyl acetate as the elutant. Appropriate fractions were combined to yield 0.52 g of 2-methoxy-5-methyl-6-oxo-5,6,7,8-tetrahydro-[1,5]naphthyridine-3-carbaldehyde. TLC Rf=0.4 (1:1 ethyl acetate:hexane). 1H NMR (CDCl3) δ 10.18 (s, 1H), 7.7 (s, 1H), 4.05 (s, 3H), 3.3 (s, 3H), 3.0 (m, 2H), 2.7 (m, 2H). Mass spectrum: m/e=221.1, (p+1).

Provenance & Evidence