Acetic Anhydride → 3-[2,4-Bis(dimethylamino)phenyl]-3-(2,5-dimethyl-3-indolyl)phthalide

Participants

Reaction Steps

A mixture of 2.0 g (0.007 mole) of 2-[(2,5-dimethyl-3-indolyl)carbonyl]benzoic acid from part A above, 1.1 g (0.007 mole) of N,N,N',N'-tetramethyl-m-phenylenediamine and seven ml of acetic anhydride was interacted in a manner similar to that described in Example 3, part E above, to obtain 2.35 g of 3-[2,4-bis(dimethylamino)phenyl]-3-(2,5-dimethyl-3-indolyl)phthalide (Formula III: R0 =R1 =R2 =R3 =R6 =H; R=R5 =CH3 ; R4 =N(CH3)2 ; Y1 =CH3), a light purple solid melting over the range of 100°-125° C. The infrared showed a characteristic absorption maximum at 1760 cm-1 (C=O; s). A toluene solution of this product spotted on acid clay or phenolic resin developed an intense violet-colored image.

Provenance & Evidence