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Rhodium (Chief Bee) 12-17-03 02:25 No 477377 |
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Myristicin-derived Cathinones (Precursor prep) (Rated as: excellent) |
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Structure and Synthesis of (±)-Wuweizisu C Gail E. Schneiders and Robert Stevenson J. Org. Chem. 46, 2969-2971 (1981) 3-Methoxy-4,5-Methylenedioxy-Propiopheno ![]() ![]() Experimental 4-Hydroxy-5-iodo-3-methoxybenzaldehyde (5-iodovanillin, 4) This was prepared as previously described18 in 81% yield by treatment of vanillin 3 with iodine monochloride and isolated as prisms from ethanol: mp 180-181°C (lit.18 mp 181-182°C). 3,4-Dihydroxy-5-methoxybenzaldehyde (5-Hydroxyvanillin, 5) This was prepared as previously described19 in 68% yield by heating 5-iodovanillin 4 with sodium hydroxide and copper sulfate solution and isolated as plates from benzene: mp 133-134°C (lit.19 mp 133-134°C). 3-Methoxy-4,5-(methylenedioxy)benzaldehy Potassium fluoride (14.0 g) and methylene chloride (75 mL) were added to a solution of 3,4-dihydroxy-5-methoxybenzaldehyde 5 (9.0 g) in dimethylformamide (300 mL), and the mixture was heated under reflux with stirring under a nitrogen atmosphere for 1.5 h. It was then diluted with water (ca. 200 mL) and extracted with ether (3x200 mL), and the extract was washed successively with 5% aqueous sodium hydroxide solution (3x150 mL), water, and brine. Evaporation of the dried (MgSO4 extract yielded a residue, which on crystallization from methanol gave the methoxy(methy1enedioxy)benzaldehyde 6 as prisms: 6.15g; mp 131-132°C (lit.22 mp 130°C). 3-Methoxy-4,5-(methylenedioxy)propiophen A solution of 3-methoxy-4,5-(methylenedioxy)benzaldehy To a solution of this alcohol (3.0 g) in acetone (25 mL) at 0-5°C was added Jones reagent (1.4 M, 8 mL) dropwise over 10 min, the mixture was stirred at room temperature for 30 min, and then 2-propanol (3 mL) was added. It was worked up by aqueous dilution, concentration, and ether extraction. The washed and dried ether extract yielded crocatone (7) as needles (2.23 g) from petroleum ether: mp 88-89°C (lit.16 mp 89°C). ![]() To a solution of the ketone 7 (2.0 g) in chloroform (12 mL) was added dropwise with stirring a solution of bromine (1.4 g) in chloroform (7 mL), and the mixture was allowed to stand for 1.5 h. It was then washed with water (25 mL) and saturated sodium bicarbonate solution (2x25 mL), dried, and evaporated to give the bromo ketone 8 as long white needles (2.20 g) from ethanol: mp 114.5-115°C. References (16) Janot, M.-M.; Robineau, C.; Le Men, J. Bull. Soc. Chim. Biol. 37, 361 (1955) (17) Plat, M.; Le Men, J.; Janot, M.-M. Bull. Soc. Chim. Biol. 45, 1119 (1963) (18) Nishinaga, A.; Matsuura, T. J. Org. Chem. 29, 1812 (1964) Post 477375 (Rhodium: "Vanillin --ICl--> 5-Iodovanillin", Novel Discourse) (19) Banerjee, S. K.; Manolopoulo, M.; Pepper, J. M. Can. J. Chem. 40, 2175 (1962) Post 403132 (Rhodium: "5-Hydroxyvanillin from 5-Iodovanillin", Novel Discourse) (20) Clark, J. H.; Holland, H. L.; Miller, J. M. Tetrahedron Lett. 3361 (1976) (22) Semmler, F. W. Ber. Dtsch. Chem. Ges. 24, 3818 (1891) The Hive - Clandestine Chemists Without Borders |
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