1,3-Dibromopropane → 1-benzyl-3-(3-bromopropyl)-5-methyl-1H-pyrimidine-2,4-dione

Temperature

60 °C

To a solution of 1-benzyl-5-methyl-1H-pyrimidine-2,4-dione (1.0 g, 4.6 mmol) in N,N-dimethylformamide (15 mL) was added tetrabutylammonium bromide (60 mg, 0.2 mmol) and sodium hydroxide (200 mg, 5.1 mmol). The suspension was stirred vigorously, heated to 60° C. for 1.5 h and then cooled to ambient temperature. 1,3-Dibromopropane (0.5 mL, 5.1 mmol) was added, the reaction was heated to 50° C. for 16 h and then concentrated in vacuo. The residue was taken up in ethyl acetate:water (1:1 200 mL), the layers separated and the aqueous layer extracted with ethyl acetate (2×50 mL). The organic layers were combined and washed with 1 M sodium hydroxide (1×50 mL), water (1×50 mL), brine (1×100 mL), dried with magnesium sulfate, filtered and concentrated in vacuo. The resulting oil was purified by pressurized silica gel chromatography (25-30% ethyl acetate in hexane) to provide 1-benzyl-3-(3-bromopropyl)-5-methyl-1H-pyrimidine-2,4-dione.

1. temperaturecooled to ambient temperature
2. temperaturethe reaction was heated to 50° C. for 16 h
3. concentrationconcentrated in vacuo
4. customthe layers separated
5. extractionthe aqueous layer extracted with ethyl acetate (2×50 mL)
6. washwashed with 1 M sodium hydroxide (1×50 mL), water (1×50 mL), brine (1×100 mL)
7. dry with materialdried with magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe resulting oil was purified by pressurized silica gel chromatography (25-30% ethyl acetate in hexane)

ORD record

ord-893b0f3cff214b7c904dde7eb6ba1ad8

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06232318B1