奥美普林（5-(4,5-二甲氧基-2-甲基苄基)-2,4-二氨嘧啶）？ 请尽量去【 scifinder & reaxys 】板块 有机化合物合成方法和路线求助、应助有关的交流板块！求助者扣3金币。 但是还是帮你一下吧. this example follows the procedure described by manchand et al., journal of organic chemistry 1992, 57, 3531-3535. briefly, in step 14,5-dimethoxy-2-methyl-benzaldehyde and sodium methoxide were dissolved in cold methanol and stirred under nitrogen at room temperature for 18 hours. the mixture was cooled to -15° c., and crude 3-(4,5-dimethoxy-2-methyl-phenyl)-2-methoxymethyl-acrylonitrile was collected as filtrate. in step 2,3-(4,5-dimethoxy-2-methyl-phenyl)-2-methoxymethyl-acrylonitrile and sodium methoxide were dissolved in dry dmso and stirred for 3.5 hours at 85° c. under nitrogen. guanidine carbonate was then added to the stirring solution, after which the temperature was raised to 125° c. for three hours, during which methanol removed via a dean-stark trap. the solution was cooled to room temperature, diluted with water, and the crude filtrate was recrystallized in dmf to yield 5-(4,5-dimethoxy-2-methyl-benzyl)-pyrimidine-2,4-diamine as a white solid. mp: 232° c. mass spec (m+h): 275. the synthetic procedure used in this example is outlined in scheme h. this example follows the procedure described by manchand et al., journal of organic chemistry 1992, 57, 3531-3535. briefly, in step 1 4,5-dimethoxy-2-methyl-benzaldehyde and sodium methoxide were dissolved in cold methanol and stirred under nitrogen at room temperature for 18 hours. the mixture was cooled to -15° c., and crude 3-(4,5-dimethoxy-2-methyl-phenyl)-2-methoxymethyl-acrylonitrile was collected as filtrate. in step 2, 3-(4,5-dimethoxy-2-methyl-phenyl)-2-methoxymethyl-acrylonitrile and sodium methoxide were dissolved in dry dmso and stirred for 3.5 hours at 85° c. under nitrogen. guanidine carbonate was then added to the stirring solution, after which the temperature was raised to 125° c. for three hours, during which methanol removed via a dean-stark trap. the solution was cooled to room temperature, diluted with water, and the crude filtrate was recrystallized in dmf to yield 5-(4,5-dimethoxy-2-methyl-benzyl)-pyrimidine-2,4-diamine as a white solid. mp: 232° c. mass spec (m+h): 275. preparation of 2,4-diamino-5-(4,5-dimethoxy-2-methylbenzyl)pyrimidine a mixture of 12.3 g. of 2,4-diamino-5-methoxymethylpyrimidine, 11 g. of 3,4-dimethoxytoluene and 72 g. of orthophosphoric acid was heated with good stirring at 110° for 4.5 hours. at the end of this time, the reaction was cooled, 30 ml. of water added, and the resulting solution added dropwise with stirring to 195 ml. of a cooled (0°) 50 percent potassium hydroxide solution. the resulting mixture was then allowed to digest in the refrigerator overnight and then was filtered. the residue was washed with small portions of ice water until the filtrate reached a ph 8-9. the resulting off-white colored solid was dried in a vacuum oven at 50° for 3 hours to give 20.5 g. of crude 2,4-diamino-5-(4,5-dimethoxy-2-methylbenzyl)-pyrimidine (104 percent of theory), melting point 217°-222°. 查看更多
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