Lithium hydroxide, monohydrate → 6-Amino-2-fluoro-9-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl)-9H-purine

Participants

Reaction Steps

A suspension of 1f (430 mg, 0.99 mmol) in 1:1 MeCN-H2O (40 mL) was treated in one portion with solid lithium hydroxide monohydrate (125 mg, 2.97 mmol). The reaction became a clear solution after being stirred at room temperature for 20 minutes. A 3-h TLC aliquot showed the deblocking to be Glacial acetic acid (57 μl) was added, and the solution was evaporated until white solid deposited. After being chilled, the solid was collected, washed with cold water, and dried in vacuo at room temperature to give crude 1g, 252 mg. This solid was dissolved in 40 mL of water and applied to a water-equilibrated SM-4 Bio-Bead column (1.5×32 cm). After initial elution with water, the product was eluted with a stepwise gradient, 5% →20% EtOH in water. The residue from the combined, evaporated column fractions was crystallized from 25 mL of boiling water with charcoal treatment and dried in vacuo at 56° C. for 16 hours to give pure 1g: 178 mg (59%). Mp 207°-209° C.; TLC 5:1 CHCl3 -MeOH, Rf 0.50; HPLC 99%, 9:1 H2O-MeCN; MS, z/e 288 (M+1)+ ; UV λ max pH 1 261 (14.0), 268 (sh), pH 7 260 (15.1), 268 (sh), pH 13 261 (14.9), 268 (sh). Anal. Calcd. for C10H11F2N5O3 ·H2O: C, 39.35; H, 4.29; N, 22.94. Found: C, 39.51; H, 4.21; N, 22.94.

Provenance & Evidence