N,N-Dimethylaniline → 2-amino-6-chloro-9-(2,3,5-O-triacetyl-beta-D-ribofuranosyl)-9H-purine

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Reaction Conditions

Reaction Steps

A mixture of the compound of Example 1 (480 g, 1.17 M), N,N-dimethylaniline (150 mL), tetraethylammonium chloride (386.4 g) and acetonitrile (0.70 L) is prepared, and then phosphorous oxychloride (400 mL) is added slowly (dropwise) over 3 hours at room temperature under a N2 atmosphere. After the addition, the mixture is heated at 100° C. for 14 minutes, and then cooled to room temperature. Most of the solvent is removed in vacuo to yield a red oil. The oil is treated with methylene chloride (CH2Cl2)(2 L), and then poured into ice water (1.5 L). The organic layer is separated and the aqueous layer extracted with CH2Cl2 (3×500 mL). The separated organic layer and the organic extracts are combined, washed with a saturated sodium bicarbonate solution until a pH of 6 to 7 is reached, and then washed with ice-water (2 ×1 L). The organic layer is dried over sodium sulfate, and the solvent removed in vacuo to yield a thick oil. The oil is treated with isopropanol (200 mL), stirred at 45° C. for 1 hour, allowed to cool to room temperature, and left overnight whereupon a precipitate is formed. The precipitate is isolated by filtering and then the precipitate is washed with cold isopropanol to yield the title compound (235 g, 47%).

Provenance & Evidence