反应详情

To a stirred suspension of 4-(3-methyl-4-oxo-3,4-dihydro-pteridin-6-yl)-piperazine-1-carboxylic acid tert-butyl ester (428 mg, 1.24 mmol; see Example 16 (d) above) in methanol (5 mL) was added 10% aqueous sodium hydroxide (5 mL). The reaction mixture was stirred overnight at room temperature and concentrated in vacuo. The residue was then diluted with water and neutralized with formic acid (pH 7). The resulting precipitate was removed by filtration and the filtrate was acidified with formic acid (pH 4) and extracted with methylene chloride. The combined organic phases were washed with brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo to afford 5′-amino-2,3,5,6-tetrahydro-[1,2′]bipyrazinyl-4,6′-dicarboxylic acid 4tert-butyl ester as a yellow solid (265 mg, 67%). 1H NMR (300 MHz, CDCl3) δ1.49 (s, 9 H), 3.38 (t, J=5.4 Hz, 4H), 3.60 (t, J=5.4 Hz, 4H), 6.06 (br s, 1H), 8.15 (s, 1 H); 13C NMR (75 MHz, CDCl3) δ28.39, 46.16, 80.29, 116.40, 138.73, 147.39, 149.67, 154.59, 165.95.

1. concentrationconcentrated in vacuo
2. additionThe residue was then diluted with water and neutralized with formic acid (pH 7)
3. customThe resulting precipitate was removed by filtration
4. extractionextracted with methylene chloride
5. washThe combined organic phases were washed with brine
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated in vacuo