Sodium hydride → Tert-butyl(3-methyl-2-oxotetrahydropyrimidin-1(2H)-yl)acetate

A solution of 0.30 g (2.6 mmol) of 1-methyltetrahydropyrimidin-2(1H)-one from step A above in 5 mL of anhydrous DMF was added to a 10 mL round bottom flask containing 0.16 g (4.2 mmol) of a 60% sodium hydride suspension in mineral oil under an atmosphere of nitrogen. After stirring for 10 min 0.62 g (3.2 mmol) of tert-butyl bromoacetate was added in one portion and the reaction mixture was allowed to stir overnight. The reaction mixture was then quenched with 5 mL of a saturated aqueous ammonium chloride solution and then diluted with 20 mL of water. The resulting suspension was extracted with ethyl acetate (3×10 mL) and the combined organics were washed with water (2×3 mL), brine (1×3 mL) and dried over magnesium sulfate. The mixture was filtered, evaporated and purified by silica gel chromatography eluting with a 0-5% methanol in ethyl acetate gradient to afford the title compound as a clear oil (0.090 g, 15%). 1HNMR (500 MHz, CDCl3) δ: 3.88 (s, 2H), 3.23 (t, J=6 Hz, 2H), 3.20 (t, J=6 Hz, 2H), 2.84 (s, 3H), 1.94-1.89 (m, 2H), 1.37 (s, 9H). LC-MA: m/z (ES) 229 (MH)+.

1. additionwas added in one portion
2. customThe reaction mixture was then quenched with 5 mL of a saturated aqueous ammonium chloride solution
3. additiondiluted with 20 mL of water
4. extractionThe resulting suspension was extracted with ethyl acetate (3×10 mL)
5. washthe combined organics were washed with water (2×3 mL), brine (1×3 mL)
6. dry with materialdried over magnesium sulfate
7. filtrationThe mixture was filtered
8. customevaporated
9. custompurified by silica gel chromatography
10. washeluting with a 0-5% methanol in ethyl acetate gradient

ORD record

ord-269dea794fe944f58749414a823594e6

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08247415B2