Ethyl Bromide → HCID 19795531, compound

Participants

Reaction Steps

3.12 g of 4.4'-bis-dimethylaminobenzophenone-2-carboxylic acid and 1.9 g of 1-ethyl-3-methyl-6-methoxyindol are stirred at 40° C. in 30 ml of acetic anhydride for 3 hours. The reaction mixture is poured onto ice, the resulting mixture is basified with NaOH and extracted with toluene. The organic phase is separated off, and treated with active carbon, dried and evaporated. The residue is decrystallized once from diethyl ether and once from toluene to give 3.35 g of 3-(4-dimethylaminophenyl)-3-(1-ethyl-3-methyl-6-methoxyindol-2-yl)-6-dimethylaminophthalide of the formula ##STR113## melting point 224°-225° C. On acid clay this compound produces a blue colour. The 1-ethyl-3-methyl-6-methoxyindol used is prepared as follows: 4.6 g of 3-methyl-6-methoxyindole [Chem ber 98, 1727 (1965)]are presented in 29 ml of dimethyl sulfoxide. 6.6 ml of 10 n aqueous KOH are then added, and 3.25 g of ethyl bromide are added dropwise at 20° C. in the course of 30'. 1 hour later the reaction mixture is poured onto water and extracted with toluene. Chromatography over silica gel (hexane/ether 5:1) gives 3.9 g of 1-ethyl-3-methyl-6-methoxyindol in the form of an oil.

Provenance & Evidence