5-羟甲基尿嘧啶的合成如何提高产率，希望得到帮助？Example 1a 5-(Hydroxymethyl)-1,3-dihydropyrimidine-2,4-dione A 2-L, three-necked flask equipped with a mechanical stirrer, thermometer, condenser, and nitrogen-inlet bubbler was charged with uracil (185.0 g, 1650 mmol) (Aldrich), paraformaldehyde (61.50 g, 2050 mmol as formaldehyde) (Aldrich), and a solution of potassium hydroxide (86.9%, 59.95 g, 928.5 mmol) (Aldrich) in water (1.445 L). The mixture was stirred at 50-52° C. for 68 h. TLC analysis indicated complete reaction. After concentration at 60° C./14 mmHg to a volume of ca. 500 mL, the residue was diluted with acetone (500 mL). The resulting precipitate was collected by filtration, washed with acetone, and dried by suction, then at 50° C./25 mmHg to give crude 5-(hydroxymethyl)-1,3-dihydropyrimidine-2,4-dione (250 g) as a white solid. The combined mother liquor and washes were concentrated to a volume of ca. 100 mL and a solution of hydroxylamine hydrochloride (27.52 g, 396.0 mmol, Aldrich) in water (100 mL) was added. The resulting precipitate was collected by filtration, washed with acetone, and dried by suction to give second crop of crude 5-(hydroxymethyl)-1,3-dihydropyrimidine-2,4-dione (34 g) as a white solid. The two lots were combined (244 g, 4% overweight) and used directly in the next step. Chen, Yi; Daniewski, Andrzej Robert; Harris, William; Kabat, Marek Michal; Liu, Emily Aijun; Liu, Jin-Jun; Luk, Kin-Chun; Michoud, Christophe US2004/38995, 2004, A1 看了一下操作，比较好操作，有可能影响收率的点： 1. 反应终点的检测是否准确 2. 多聚甲醛用的是无水的还是含水的 3. 水是否完全旋干，产品可能会溶水查看更多
第1天
关注盖德视界
添加小助手
