Phosphorus oxychloride → 4-Chloro-2-methylthieno[3,2-d]pyrimidine

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Reaction Steps

2-Methylthieno[3,2-d]pyrimidin-4(3H)-one (compound 32b, 0.18 g, 1.13 mmol) was heated to 110° C. in POCl3 overnight. The solvent was removed under reduced pressure, and the residue was neutralized with saturated NaHCO3 solution. The product was extracted into CH2Cl2, and the organic phase separated, washed with brine, and dried (MgSO4). After removal of the solvent compound 32c was obtained as a yellow-orange solid (0.21 g, 88%). Compound 32c was used without further purification. Rf=0.16 (10% EtOAc/hexane). 1H NMR (400 MHz, DMSO-d6): δ 2.71 (s, 3H), 7.66 (d, J=5.6 Hz, 1H), 8.54 (d, J=5.6 Hz, 1H). LCMS 185 (M+H). Anal. (C23H29N8OF.0.35H2O.0.35 hexane) C, H, N. HPLC>98% purity.

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