4-Fluorobenzyl bromide → Methyl 3-benzyloxy-5-(4-fluorobenzyl)-4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate

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Reaction Steps

The title compound was prepared from methyl 3-benzyloxy-4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylate using a procedure similar to that found in Example 13, Step 1, except that 4-fluorobenzyl bromide was used in place of iodomethane. Purification was achieved by flash column chromatography on silica gel using a gradient elution of 0-6% MeOH/CH2Cl2, and collection and concentration of appropriate fractions afforded the title product. 1H NMR (400 MHz, CDCl3) δ 7.57-7.55 (d, 2H), 7.38-7.29 (m, 5H), 7.08-7.03 (m, 2H), 5.40 (s, 2H), 4.74 (s, 2H), 4.33-4.30 (t, 2H), 3.93 (s, 3H), 3.63-3.59 (t, 2H); ES MS (M+1)=410.

Provenance & Evidence