Methylamine → Ethyl 6-benzyloxy-1-methyl-2,5-dioxo-1,2,3,5-tetrahydroimidazo[1,2-a]pyrimidine-7-carboxylate

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Reaction Conditions

Reaction Steps

A solution of intermediate 3, ethyl 5-(benzyloxy)-1-(methoxycarbonylmethyl)-2-(methylsulfonyl)-6-oxo-1,6-dihydropyrimidine-4-carboxylate, (0.790 g, 1.86 mmol) in tetrahydrofuran (10 ml) was treated with a 2 M solution of methylamine in tetrahydrofuiran (10 ml, 20.0 mmol) and the resulting mixture was stirred at 22° C. for 1 h. The solvent was then evaporated in vacuo and the residue was diluted with ethyl acetate, washed successively with saturated sodium bicarbonate, brine and dried over anhydrous magnesium sulfate. Evaporation of the solvent followed by recrystallization of the solid residue from ethyl acetate/hexane gave 0.705 g (83% yield) of the title ester as white crystals; mp 167° C. 1HNMR 400 MHz (CDCl3) δ (ppm): 1.34 (3H, t, J=7.1 Hz, CH3), 3.29 (3H, s, NCH3), 4.37 (2H, q, J=7.2 Hz, OCH2), 4.55 (2H, s, CH2), 5.23 (2H, s, OCH2), 7.3–7.5 (5H, m, aromatics). Anal. Calcd for C17H17N3O5: C, 59.47; H, 4.99; N, 12.23. Found: C, 59.5, H, 5.07; N, 12.40.

Provenance & Evidence