3-Nitrophenylboronic Acid → ethyl 4-(3-nitrophenyl)-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To ethyl 4-chloro-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate (10.0 g, 44.3 mmol), (3-nitrophenyl)boronic acid (11.8 g, 70.9 mmol), PdCl2(dppf)-CH2Cl2 (3.62 g, 4.43 mmol) and aqueous sodium carbonate (2 M solution, 55.4 mL, 111 mmol) in a flask was added DMF (148 mL). The mixture was degassed for 10 minutes then heated at 115° C. for 1.5 hours. The reaction was cooled to ambient temperature, then water was added and the mixture was extracted with DCM (×3) and EtOAc (×1). The combined organics were concentrated, diluted with EtOAc (300 mL) and washed with sorbitol/Na2CO3 solution to remove excess boronic acid. The aqueous layer was extracted with EtOAc (×4). The combined organics were concentrated after which EtOAc and hexanes were added with stirring. The resulting precipitate was filtered to give solid product that was further triturated with DCM and hexanes to give ethyl 4-(3-nitrophenyl)-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate. The combined organic fractions were concentrated under reduced pressure to give a residue containing product and DMF. Addition of MeOH and water led to formation of a precipitate which was filtered to afford additional ethyl 4-(3-nitrophenyl)-7H-pyrrolo[2,3-d]pyrimidine-5-carboxylate. LRMS (ESI) calc'd for C15H13N4O4 [M+H]+: 313, found 313. 1H NMR (600 MHz, DMSO-D6) δ 13.17 (s, 1H), 8.99 (s, 1H), 8.43 (s, 1H), 8.39-8.36 (m, 2H), 8.12 (d, J=7.8 Hz, 1H), 7.79 (t, J=7.8 Hz, 1H), 3.93 (q, J=7.2 Hz, 2H), 0.95 (t, J=7.2 Hz, 3H).

Provenance & Evidence