反应详情

温度

145 °C

Into each of three microwave vials is added {2-[N′-(5-ethyl-2-methyl-6-oxo-1,6-dihydro-pyridine-3-carbonyl)-hydrazino]-2-oxo-ethyl}-carbamic acid tert-butyl ester (190 mg, 0.519 mmol), tosyl chloride (119 mg, 0.624 mmol), and 2-t-butylimino-2-diethylamino-1,3-dimethyl-perhydro-1,3,2-diazaphosphorine on polystyrene (2.2 mmol/g, 1.18 g, 2.6 mmol) and anhydrous tetrahydrofuran (6 mL). Each vial is flushed with nitrogen, sealed and heated in the CEM Discover microwave at 145° C. holding at that temperature for 3 min, with a maximum pressure of 7.3 bar. LC/MS shows the reaction is complete. The product from all three vials are filtered and washed with THF. The filtrate is evaporated, and the residue is purified by flash chromatography on a 5-gram silica gel cartridge by elution with dichloromethane:ethyl acetate (3:1). Fractions containing the product are combined again and evaporated to give [5-(5-ethyl-6-methoxy-2-methyl-pyridin-3-yl)-[1,3,4]oxadiazol-2-ylmethyl]-carbamic acid tert-butyl ester (329 mg, 61% yield). MS: m/e 719 (95%) (2M+Na), 249 (100%) (M+H); 1H NMR (CDCl3, δ, ppm): 7.87 (1H, s), 5.15 (1H, br.), 4.61 (2H, br.d), 4.00 (3H, s), 2.79 (3H, s), 2.60 (2H, q), 1.49 (9H, s), 1.21 (3H, t).

1. customEach vial is flushed with nitrogen
2. customsealed
3. filtrationThe product from all three vials are filtered
4. washwashed with THF
5. customThe filtrate is evaporated
6. customthe residue is purified by flash chromatography on a 5-gram silica gel cartridge by elution with dichloromethane:ethyl acetate (3:1)
7. additionFractions containing the product
8. customevaporated