反应详情

The solution of bromopropylamine base, cooled to 0° C., was slowly added dropwise with vigorous stirring and cooling to maintain the temperature below to the methanolic solution of Step A containing 1,2-dibutoxy-1-cyclobutene-3,4-dione. The mixture was stirred at 20° C. for 2 hours, polish filtered through diatomaceous earth, washed with methanol (2×0.25L) and the filtrate was added over a period of 1 hour with vigorous stirring to water (31.1L). The mixture was stirred at 0° C. for 2 hours. The solid was collected by filtration, washed with water (3×2L) and dried to vacuo at 50° C. to give 2137 g (84% yield) of the title compound as an off-white solid; m.p.=69° C.

1. additionwas slowly added dropwise
2. temperaturecooling
3. stirringThe mixture was stirred at 20° C. for 2 hours
4. filtrationpolish filtered through diatomaceous earth
5. washwashed with methanol (2×0.25L)
6. additionthe filtrate was added over a period of 1 hour
7. stirringwith vigorous stirring to water (31.1L)
8. stirringThe mixture was stirred at 0° C. for 2 hours
9. filtrationThe solid was collected by filtration
10. washwashed with water (3×2L)
11. customdried to vacuo at 50° C.