Yield:-

Reaction Conditions:

with triethylamine in tetrahydrofuran;

Steps:

W.1 (E)-1-[2-(Acetylamino)ethylidene]-7-methoxy-1,2,3,4-tetrahydronaphthalene

Working Example 1 (E)-1-[2-(Acetylamino)ethylidene]-7-methoxy-1,2,3,4-tetrahydronaphthalene To a solution of 1-(2-aminoethylidene)-7-methoxy-1,2,3,4-tetrahydronaphthalene (2.0 g, 9.74 mmol) and triethylamine (1.5 g, 14,6 mmol) in THF (20 ml) was gradually added dropwise, under ice-cooling, acetyl chloride (0.76 g, 9.74 mmol). The mixture was stirred for 30 minutes at room temperature. The reaction mixture was poured into water, and the organic layer was subjected to extraction with chloroform. The extract solution was washed with brine and water, which was dried over anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure. The residue was purified by means of a silica gel column chromatography (ethyl acetate), followed by recrystallization from ethyl acetate/hexane to give the above-titled compound (yield 0.96 g, 40%). m.p.92-94° C. (recrystallized from ethyl acetate/hexane) NMR(CDCl₃) δ: 1.73-1.90(2H,m), 2.01(3H,s), 2.51(2H,t,J=5.8 Hz), 2.71(2H,t,J=6.2 Hz), 3.80(3H,s), 4.06(2H,t,J=6.2 Hz), 5.62(1H,br s), 5.94(1H,m), 6.75(1H,dd,J=2.6 Hz,8.4 Hz), 7.01(1H,d,J=8.4 Hz), 7.06(1H,d,J=2.6 Hz). Elemental Analysis for C₁₅H₁₉NO₂: Calcd.: C, 73.44; H, 7.81; N, 5.71. Found: C, 73.52; H, 7.86; N, 5.73.

References:

US6235789,2001,B1