3-[2,4-Bis(dimethylamino)phenyl]-3-(1-ethyl-2-methyl-3-indolyl)-6-nitrophthalide → 3-[2,4-Bis(dimethylamino)phenyl]-3-(1-ethyl-2-methyl-3-indolyl)-6-aminophthalide

Participants

Reaction Conditions

Reaction Steps

A solution of 25.0 g (0.054 mole) of 3-[2,4-bis(dimethylamino)phenyl]-3-(1-ethyl-2-methyl-3-indolyl)-6-nitrophthalide, prepared as described in part B above, in 285 ml of concentrated hydrochloric acid was heated to 60° C. at which temperature 31.25 g (0.142 mole) of stannous chloride dihydrate was added at such a rate as to maintain the temperature at 60° C. After the addition was complete, the solution was heated to 70° C. and held there for a period of one hour and then allowed to cool to 25° C. The green-colored solid which separated was collected by filtration and was slurried in five percent aqueous sodium hydroxide solution. The resulting suspension was extracted with 500 ml of toluene at room temperature and the toluene extract was filtered, decolorized, and dried over sodium sulfate. On standing, a cream solid separated from the toluene solution. The solid was filtered off and dried to obtain 2.9 g of 3-[2,4-bis(dimethylamino)phenyl]-3-(1-ethyl-2-methyl-3-indolyl)-6-aminophthalide (Formula III: R°=R1 =R3 =Y1 =H; R2 =NH2 ; R=R5 =CH3 ; R4 =N(CH3)2 ; R6 =CH2CH3) having a melting point of 206°-209° C. Infrared analysis showed a maximum at 1727 cm-1 (C=O; s). The nuclear magnetic resonance spectrum was concordant with the assigned structure. A toluene solution of the above compound developed an intense grape-black color when spotted on a paper coated with phenolic resin.

Provenance & Evidence