反应详情

4.59 g (23.8 mmol) of (±)-2-methyl-3-oxo-6-hydroxymethyl-3,4-dihydro-2H-1,4-benzoxazine is mixed with 5.53 g (54.6 mmol) of triethylamine after being dissolved in 900 ml of methylene chloride. At 0° C., 4.08 g (35.6 mmol) of methanesulfonic acid chloride is added in drops, and the batch is then stirred at room temperature for 5 hours. Another 3.8 ml of triethylamine and 1.4 ml of methanesulfonic acid chloride are added and stirred again for 20 hours at room temperature. A portion of methylene chloride (600 ml) is spun off. After dilution with 1 l of diethyl ether, the organic phase is washed twice with 50 ml of water each, once with 50 ml of saturated sodium bicarbonate solution and again with 50 ml of water. The organic phase is spun in after drying, and the residue is chromatographed on silica gel (mobile solvent: methylene chloride/ethanol). 2.95 g (58.7%) of the desired product in addition to 1.1 g (16.6%) of the corresponding mesylate are obtained, melting point 162-169° C.

1. stirringstirred again for 20 hours at room temperature
2. washAfter dilution with 1 l of diethyl ether, the organic phase is washed twice with 50 ml of water each, once with 50 ml of saturated sodium bicarbonate solution
3. customin after drying
4. customthe residue is chromatographed on silica gel (mobile solvent: methylene chloride/ethanol)
5. addition2.95 g (58.7%) of the desired product in addition to 1.1 g (16.6%) of the corresponding mesylate
6. customare obtained