Ammonia → HCID 14181389, compound

Participants

Reaction Steps

9'-Chloro-2',3',4',10'-tetrahydrospiro[1,3-dioxolane-2,10'-pyrimido(1,2-a)indole] (6.58 g) was added to cooled 98% sulphuric acid (35 ml) with stirring until complete solution was achieved (approx. 2 hours). The solution was poured on to ice (400 ml) and basified to pH9 with conc. ammonia solution. The resulting suspension of the product was stirred with chloroform (100 ml), and after separation, the aqueous phase was exhaustively extracted with further chloroform. Evaporation of the combined, dried (MgSO4) extracts left a brownish orange solid (4.83 g) which was crystallised from benzene to give 9-chloro-3,4-dihydropyrimido[1,2-a]indol-10(2H)-one as dark orange prisms (3.16 g) darkening above 165° and melting at 170° with decomposition.

Provenance & Evidence