Water → 7-bromo-9-fluoro-1H-pyrimido[5,4-b]indole-2,4(3H,5H)-dione

Participants

Reaction Steps

15.4 g (56.6 mmol) 3-amino-6-bromo-4-fluoro-1H-indole-2-carboxylic acid amide was suspended in 300 ml dioxan and after the addition of 7.5 ml (61.8 mmol) diphosgene the suspension was refluxed for 2 h. Having cooled down to room temperature, 20 ml water was carefully added and the precipitate was subsequently sucked off. 12.5 g (74%) 7-bromo-9-fluoro-1H-pyrimido[5,4-b]indole-2,4(3H,5H)-dione was obtained. ESI-MS [m/z]: 296, 298 [M−H]−

Provenance & Evidence