1-[(2-Acetoxyethoxy)methyl]-3-ethyl-6-azauracil

The product 2 was prepared via a direct condensation under solid-liquid phase transfer catalysis (S.L.P.T.C.) [1] conditions. To a solution of 0.02 mmole of tetraglyme in 4 ml of anhydrous THF, 0.11 mmole of potassium tert-butoxide is added. Then 0.1 mmole of the acyclonucleoside 1 [2] is added, the reaction mixture is stirred at room temperature for 15 min. The reaction mixture is cooled to 0°C and 0.11 mmole of alkylating agent in 2 ml of dry THF is added dropwise with stirring. When the addition is finished, the reaction mixture is stirred at 0°C for 30 min. The reaction mixture is then filtered and the filtrate is evaporated in vacuo to dryness. The residue is then chromatographed on a silica gel column and the expected acyclonucleoside 2 was isolated. Yield: 90 % (viscous and colourless).

Rf: 0.77 (CHCl3 / MeOH, 9/1, V/V).

¹H NMR (CDCl3): 1.33 (t, 3H, CH3CH2); 2.06 (s, 3H, COOCH3); 3.75 (m, 2H, OCH2CH2O); 4.15 (m, 4H, OCH2CH2O, CH3CH2); 5.42 (s, 2H, OCH2N); 7.45 (s, 1H, H⁵).

UV (l max (nm), H₂O): 273.

MS (FAB, m/z): 258 [MH]⁺

Anal. calc. for C10H15N3O5: C 46.69, H 5.87, N 16.33; Found: C C 46.60, H 5.78, N 16.22.