Diisopropylamine → 6-[2-[4-(1H-indol-1-yl)-1-piperidinyl]ethyl]-1,2,7-trimethylimidazo[1,2-a]pyrimidin-5(1H)-one

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Reaction Steps

A mixture of 6-(2-bromoethyl)-1,2,7-trimethyl-1H,5H-imidazo[1,2-a]pyrimidin-5-one (8.85 g), prepared as described in EP-0,378,255, 1-(4-piperidinyl)-1H-indole (2 g) and N-(1-methylethyl)-2-propanamine (1.2 g) in ethanol (100 ml) was stirred and refluxed for 6 hours. The solvent was evaporated and the residue was stirred in water and subsequently extracted with CH2Cl2. The separated organic layer was dried, filtered and the solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: CH2Cl2 /CH3OH 95/5). The pure fractions were collected and the solvent was evaporated. The residue was crystallized from CH3CN/DIPE and the precipitate was filtered off and dried, yielding 2.5 g (62%) 6-[2-[4-(1H-indol-1-yl)-1-piperidinyl]ethyl]-1,2,7-trimethylimidazo[1,2-a]pyrimidin-5(1H)-one (compound 9; mp. 165.7° C.).

Provenance & Evidence