Phosphorus oxychloride → 4-Chloro-5-methyl-5,7-dihydrofuro[3,4-d]pyrimidine

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Reaction Steps

To a suspension of 5-methyl-5,7-dihydrofuro[3,4-d]pyrimidin-4-ol (1.2 g, 7.9 mmol) in acetonitrile (50 mL) was added via syringe POCl3 (3.6 g, 23.7 mmol) and the mixture heated to reflux for 3 hours. The mixture was allowed to cool to room temperature and then concentrated. The residue was diluted with EtOAc and quenched by pouring into saturated NaHCO3. The organic layer was separated and the aqueous layer extracted with EtOAc (3×100 mL). The combined organic layers were dried (MgSO4) and concentrated to give 4-chloro-5-methyl-5,7-dihydrofuro[3,4-d]pyrimidine (1.3 g, 96%) as a light brown oil which was used in the next step without further purification. 1H NMR (CDCl3, 400 MHz) δ 8.89 (s, 1H), 5.46 (q, J=6.4 Hz, 1H), 5.15 (dd, J=14.4, 2.8 Hz, 1H), 5.02 (dd, J=14.4, 2.8 Hz, 1H), 1.62 (d, J=6.4 Hz, 3H).

Provenance & Evidence