Methyl iodide → 5-Benzyloxy-6-methoxy-2-methylsulfanyl-pyrimidine-4-carboxylic acid ethyl ester

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Reaction Steps

5-Benzyloxy-2-methylsulfanyl-6-oxo-1,6-dihydro-pyrimidine-4-carboxylic acid ethyl ester (6.190 g, 19.32 mmol) in dry N,N-dimethylformamide (60 ml) was reacted at 10° C. with sodium hydride (0.90 g of a 60% dispersion in mineral oil, 22.5 mmol) and iodomethane (1.4 ml, 21.7 mmol) and chromatographed to give first 0.581 g (9% yield) of 5-benzyloxy-6-methoxy-2-methylsulfanyl-pyrimidine-4-carboxylic acid ethyl ester as white crystals; mp 48–49° C. (ethyl acetate-hexane). 1HNMR 400 MHz (CDCl3) δ (ppm): 1.32 (3H, t, J=7.1 Hz, CH3), 2.56 (3H, s, SCH3), 4.07 (3H, s, OCH3), 4.36 (2H, q, J=7.1 Hz, CH2), 5.04 (2H, s, OCH2), 7.3–7.45 (5H, m, aromatics). HRMS (FAB POS) calculated for C16H19N2O4S [M+H+]: 335.106554. found: 335.106641, δ −0.3 ppm. The following fractions then gave 5.836 g (90% yield) of the title ester as white needles; mp 84–85° C. (ethyl acetate-hexane). 1HNMR 400 MHz (CDCl3) δ (ppm): 1.33 (3H, t, J=7.0 Hz, CH3), 2.62 (3H, s, SCH3), 3.57 (3H, s, NCH3), 4.35 (2H, q, J=7.0 Hz, CH2), 5.22 (2 H, s, OCH2), 7.3–7.5 (5H, m, aromatics). Anal. Calcd for C16H18N2O4S: C 57.47, H 5.43, N 8.38. Found: C 57.37, H 5.42, N 8.36.

Provenance & Evidence