1-[(2-Acetoxyethoxy)methyl]-3-methyl-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 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: 0.76 (CHCl₃ / MeOH, 9/1, V/V).

¹H NMR (CDCl₃): 2.06 (s, 3H, COOCH₃); 3.63 (s, 3H, CH₃); 3.75 (m, 2H, OCH₂CH₂O); 4.15 (m, 2H, OCH₂CH₂O); 5.43 (s, 2H, OCH₂N); 7.45 (s, 1H, H⁵).

UV (λ max (nm), H₂O): 273.

MS (FAB, m/z): 244 [MH]⁺.

Anal. calc. for C₉H₁₃N₃O₅: C 44.44, H 5.38, N 17.27; Found: C 44.41, H 5.28, N 17.00.