Phosphorus oxychloride → Ethyl 4-chloro-7H-pyrrolo[2,3-d]pyrimidine-6-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Under a N2 atmosphere, 32.0 g (154 mmol) of 6-ethoxycarbonyl-4-hydroxy-7H-pyrrolo[2,3-d]pyrimidine are suspended in 308 ml (338 mmol) of POCl3 at RT and warmed to 120° C. with stirring; the solid dissolves in the course of this. After stirring at 120° C. for 3 h, the excess POCl3 is distilled off (65° C. external temperature; 15 mbar). Suspension of the residue in 50 ml of ice-cold toluene, filtration and washing with toluene yields 4-chloro-6-ethoxycarbonyl-7H-pyrrolo[2,3-d]pyrimidine; m.p. 219-221° C.; 1H-NMR (DMSO-d6) 8.77 and 7.24 (2s, 2H), 4.39 (q, J=7, 2H), 1.36 (t, J=7, 3H). Further product can be obtained from the evaporated filtrate by stirring in ethyl acetate/water.

Herkunft & Nachweise