Dimethylformamide → 4-Chloro-2,6-dimethyl-5-{[2-(trimethylsilyl)ethoxy]methyl}-5H-pyrrolo[3,2-d]pyrimidine-7-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

7-Bromo-4-chloro-2,6-dimethyl-5-{[2-(trimethylsilyl)ethoxy]methyl}-5H-pyrrolo[3,2-d]pyrimidine from example A9 (12.41 g; 31.76 mmol) is dissolved in dry tetrahydrofurane (100 mL). At −78° C. n-butyllithium (12.7 mL; 31.76 mmol; 2.5M solution in n-hexane) is syringed into the stirred reaction mixture. After 30 min DMF (12.4 mL; 158.80 mmol) is added via syringe and the mixture is stirred for additional 2 hours at −78° C. and for 30 minutes at 0° C. The reaction is quenched by addition of 1M citric acid (32 mL) and brine (32 mL). After diluting with tert-butylmethylether the aqueous layer is separated and extracted with tert-butylmethylether (3×50 mL). The combined organic layers are dried over MgSO4 and the solvent is removed under reduced pressure. The residue is purified by column chromatography on silica gel (cyclohexane:ethylacetate/7:3) affording the title compound as a white solid.

Provenance & Evidence