To a stirring solution of 4,6-dichloro-5-nitro-2-(propylthio)pyrimidine (CLIN; 0.80 g, 3 mmol) in tetrahydrofuran (30 mL) at 0° C. was slowly added a solution of (1S,2S,3R,5S)-3-amino-5-(2-hydroxyethoxy)cyclopentane-1,2-diol (OLA; 0.53 g, 3 mmol) in N-methylpyrrolidin-2-one (5 mL). After 10 min there was added triethylamine (0.42 mL, 3 mmol) and the mixture left stirring for 3 h at 0° C. and then 16 h at 20° C. The reaction mixture was diluted with ethyl acetate (60 mL), washed with water (2×60 mL) and evaporated under reduced pressure. The obtained crude product was triturated under diisopropyl ether (10 mL) and filtered to give OLACIN as a yellow powder (0.86 g, 70% yield): 98 area % by HPLC; mp 94-98° C.; 13C NMR (CDCl3, 125 MHz) δ13.2, 22.3, 32.7, 33.6, 55.7, 60.3, 70.7, 74.0, 74.6, 82.5, 124.5, 151.6, 153.9, 171.9.
