Dichloromethane → (+/-)-2-tert-butyl 4-chloro 5-(4-(1-tosyloxy-but-2-oxy) benzyl)oxy 3(2H)-pyridazinone

Beteiligte Stoffe

Reaktionsschritte

Into a 10 mL round bottom flask was added the product of Example 3E (0.05 g, 0.13 mmol) followed by dichloromethane (2 mL). Toluenesulfonyl chloride (0.075 g, 0.39 mmol), 4-N,N-dimethylaminopyridine (0.048 g, 0.39 mmol) and diisopropylethylamine (0.05 g, 0.39 mmol, 68.7 μl) were then added in succession to the reaction mixture and this was stirred for 35 minutes. Water was then added to the mixture and the solution poured into a separatory funnel and the layers separated. The organic layer was washed with water and brine and dried over magnesium sulfate. The crude oil obtained after filtration and concentration was purified by silica gel flash chromatography (hexanes:ethyl acetate) to obtain 54 mg (77%) of the desired compound as a thick colorless oil. 1H (CDCl3) δ (ppm): 7.74 (3H, two singlets), 7.3 (m, 4H), 6.8 (d, 2H), 5.2 (s, 2H), 4.38 (p, 1H), 4.15 (m, 2H), 2.44 (s, 3H), 1.72 (m, 2H), 1.6 (s, 9H), 0.95 (t, 3H); 13C (CDCl3) δ (ppm): 159.2, 158.5, 153.9, 145.1, 133, 130, 129, 128.1, 127.2, 125.4, 118.5, 116.5, 71.9, 70.2, 66.6, 28.1, 24.2, 21.8, 9.4.

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