Methyl iodide → 2,6-dichloro-9-methyl-9H-purine

To a solution of 2,6-dichloropurine (1.10 g, 5.82 mmol) in anhydrous THF (5.0 mL) was added tetra-n-butylammonium fluoride (0.58 mL, 10.58 mmol, 1.8 eq; 1M in THF). Methyl iodide (0.40 mL, 6.42 mmol, 1.1 eq) was added, and the reaction mixture was stirred at RT under N2 for 30 minutes. The reaction mixture was then diluted with ethyl acetate (250 mL). The organic layer was washed with aqueous saturated sodium thiosulfate solution, water and brine, then dried (Na2SO4), filtered and evaporated in vacuo. The resultant residue was purified by column chromotagraphy (Si-PPC, gradient 5 to 100% ethyl acetate in hexane) to give 2,6-dichloro-9-methyl-9H-purine (a-2) as a white solid (780 mg, 66%) followed by gradient 0 to 30% methanol in ethyl acetate to give 2,6-dichloro-7-methyl-7H-purine (a-3) as a white solid (346 mg, 29.3%). 1H NMR of 2,6-dichloro-9-methyl-9H-purine (DMSO-d6, 400 MHz) δ ppm 8.75 (s, 1H), 3.83 (s, 3H). 1H NMR of 2,6-dichloro-7-methyl-7H-purine (DMSO-d6, 400 MHz) δ ppm 8.80 (s, 1H), 4.09 (s, 3H).

1. washThe organic layer was washed with aqueous saturated sodium thiosulfate solution, water and brine
2. dry with materialdried (Na2SO4)
3. filtrationfiltered
4. customevaporated in vacuo
5. customThe resultant residue was purified by column chromotagraphy (Si-PPC, gradient 5 to 100% ethyl acetate in hexane)

ORD record

ord-69519608f5024b6ca89abb10183a108c

Source dataset

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08288381B2