反应详情

A mixture consisting of 1.97 g (0.0100 mol) of 3,4-dimethoxybenzohydroxamic acid, mp 170-173° C. (dec.) (lit, mp 167-168° C., F. Aljundi, E. Hannig, and K. Bohm, Pharmazie, 28, 362 (1973)), 5 ml of pyridine, and 100 ml of methylene chloride was prepared in a 250 ml round bottom flask. The mixture was cooled in an ice bath, and 1.977 g (0.0100 mol) of diethylmalonyl chloride was added dropwise over a 15 minute period with stirring. The reaction mixture was stirred for 1 hour at room temperature after which time all the hydroxamic acid has dissolved. The solution was extracted three times with 50 ml portions of water, four times with 50 ml portions of 5% hydrochloric acid, and two times with 50 ml portions of 5% sodium carbonate. The methylene chloride was dried (MgSO4) and evaporated to dryness under reduced pressure to give 2.36 g (73.5%) of crude 2-(3,4-dimethoxybenzoyl)-4,4-diethylisoxazolidine-3,5dione as a solid residue. Recrystallization of the solid from absolute ethanol gave pure 2-(3,4-dimethoxybenzoyl)-4,4-diethylisoxazolidine-3 5dione as a white solid: mp 108-109° C. IR (Nujol) 1805 (s, C=0), 1752 (s, C=0), 1693 cm-1 (s, C=0); 1H NMR (400 MHz, CDCl3) δ7.40-7.54 (m, 2H), 6.94-6.96 (d, 1H), 3.98 (s, 3H), 3.94 (s, 3H), 1.97 (q, 4H), 1.02 (t, 6H); High resolution MS, calc'd for: C16H19NO6 : 321.1212. Found: 321.1208. Anal. Calc'd for: C16H19NO6 : C, 59.80; H, 5.96; N, 4.36. Found: C, 60.04; H, 6.05; N, 4.44.

1. customwas prepared in a 250 ml round bottom flask
2. temperatureThe mixture was cooled in an ice bath
3. dissolutionhas dissolved
4. extractionThe solution was extracted three times with 50 ml portions of water, four times with 50 ml portions of 5% hydrochloric acid, and two times with 50 ml portions of 5% sodium carbonate
5. dry with materialThe methylene chloride was dried (MgSO4)
6. customevaporated to dryness under reduced pressure