Diisopropylamine → 8-Bromo-6-chloro-9-methyl-9H-purine

Temperature

-78 °C

To a dry flask was added diisopropyl amine (1.6 mL, 11.42 mmol) and THF (15 mL). The solution was cooled to −78° C. and n-butyllithium (2.5M in hexanes, 4.5 mL, 11.25 mmol) was added dropwise. After stirring for 10 minutes at −78° C., the solution was warmed to 0° C. and allowed to stir for an additional 10 minutes. The solution was cooled back to −78° C. and 6-chloro-9-methyl-9H-purine (1.5 g, 8.9 mmol) was added as a suspension in THF (20 mL). After stirring for 20 minutes −78° C., 1,2-dibromotetrachloroethane was added (5.7 g, 17.5 mmol), and after an additional 20 minutes the reaction was quenched with the addition of sat. aq. NH4Cl (15 mL). Upon warming to room temperature, the solution was diluted with ethyl acetate (75 mL) and the aqueous layer was discarded. The organics were washed with brine and dried using magnesium sulfate. The solvent was removed in vacuo to provide a brown solid that was purified by column chromatography (25-50% ethyl acetate in hexanes) to yield 1.493 g tan solid product. 1H NMR (400 MHz, DMSO-d6): δ 8.84 (d, J=72.7 Hz, 1H), 3.76 (s, 3H).

1. temperaturethe solution was warmed to 0° C.
2. stirringto stir for an additional 10 minutes
3. temperatureThe solution was cooled back to −78° C.
4. additionwas added (5.7 g, 17.5 mmol)
5. customafter an additional 20 minutes the reaction was quenched with the addition of sat. aq. NH4Cl (15 mL)
6. temperatureUpon warming to room temperature
7. additionthe solution was diluted with ethyl acetate (75 mL)
8. washThe organics were washed with brine
9. customdried
10. customThe solvent was removed in vacuo
11. customto provide a brown solid that
12. customwas purified by column chromatography (25-50% ethyl acetate in hexanes)

ORD record

ord-957b8c781e9a45d29abc3d679eb0f2ec

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09346807B2