反应详情

A mixture 1-methoxy-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carboxaldehyde (67.95 g, 0.261 mol), hydroxylamine hydrochloride (19.10 g, 0.275 mol), pyridine (21 mL) and toluene (260 mL) was heated at reflux, with removal of water via a Dean-Stark trap, for 20 h. The mixture was cooled and hexane/ethyl acetate (8:1, 100 mL) and water (250 mL) was added. The layers were separated and the aqueous layer extracted with hexane/ethyl acetate (8:1, 2×50 mL). The combined organic extracts were washed with water (2×100 mL), 2N hydrochloric acid (2×100 mL), and brine (100 mL). Evaporation of solvents and crystallization from hexane provided 1-methoxy-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-carbonitrile (1), (56.17 g), mp 71°-73° C., GLC purity 99%+. 1H-NMR (CDCl3) δ 1.25 and 1.36 (12H, 2s), 1.62 (4H, s), 2.43 (3H, s), 4.07 (3H, s), 6.92 (1H, s); IR (CHCl3) νmax 2950, 2200, 1600, 1540, 1460 cm-1. MS (m/e) 257, 242, 200; UV νmax (ethanol) 224 (ε=2100), 247 (ε=2800), 289 (ε=840) nm.

1. temperatureThe mixture was cooled
2. customThe layers were separated
3. extractionthe aqueous layer extracted with hexane/ethyl acetate (8:1, 2×50 mL)
4. washThe combined organic extracts were washed with water (2×100 mL), 2N hydrochloric acid (2×100 mL), and brine (100 mL)
5. customEvaporation of solvents and crystallization from hexane