Phosphorus oxychloride → 3-Chloro-8-thia-4,6-diazatricyclo[7.4.0.0,2,7]trideca-1(9),2,4,6-tetraene

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Reaction Conditions

Reaction Steps

A mixture of 3,4,5,6,7,8-hexahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-one (0.8 g) and POCl3 (10 mL) was heated at 55-65° C. for 3 h. Water was then added followed by sodium bicarbonate. The resulting mixture was extracted with ethyl acetate. The organic layer was concentrated and the crude compound was purified by silica gel column chromatography using a mixture of hexanes:ethyl acetate (20:1), to give 4-chloro-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine (0.52 g, 60%). 1H NMR (300 MHz, CDCl3): δ 8.69 (s, 1H), 3.10-3.07 (m, 2H), 2.88-2.86 (m, 2H), 1.89-1.92 (m, 4H). LC-MS (ESI) m/z 225.3 (M+H).

Provenance & Evidence