A mixture of methyl 4-(1,4-dihydroindeno[1,2-c]pyrazol-3-yl]benzoate (2.2 g, Example 7) and N,N-diethylethylenediamine (7 ml) was boiled under reflux for 5 hours. The mixture was cooled and stood for 16 hours at ambient temperature. Petroleum ether, b.p. 60-80° C. (50 ml) was added and then decanted off to leave a gum which was further treated with petroleum ether as above and the residual gum dissolved in dichloromethane and purified by flash column chromatography on silica using dichloromethane/IMS/triethylamine (25:2:1) as the mobile phase to give a solid which was dissolved in ethanol (70 ml) and then dry hydrogen chloride gas was passed through the solution. The precipated solid was collected by filtration, washed with ethanol and dried to give N-(2-diethylaminoethyl)-4-(1,4-dihydroindeno[1,2-c]-pyrazol-3-yl)- benzamide dihydrochloride, m.p.230° C.
