Vat Dyes from Benzimidazo[1,2-b]isoquinolin-5(12H)-one

Convenient two-step synthesis of 4-(2-imidazolyl)phthalazones from o-phthaloyl dichloride

“…The ir spectrum correlated exactly with ir spectrum 911G, Aldrich Library, for 2,3-dimethylindole: ir 3492, 3060, 2940, 2880, 1625, 1550, 1476, 1346, 1310, 1270, 1253, 1010, 932, 730 cm"1; NMR (CC14) 2.19 (s, 3 H, 3-CHs), 2.32 (s, 3 H, 2-CH3), 6.50-6.85 (broad, 1 , NH), 6.90-7.45 (m, 4 H, phenyl). 2.67 (t, J = 7.1 Hz, 2 H, NCH2CH2), 3.73 (t of d, J = 7.1, 2.1 Hz, 2 H, NCH2CH2), 6.95-7.42 (m, 4, aromatic), 8.17 (t, J = 2.1 Hz, 1 H, ¡mino H).…”

“…We have found that the carboxylic acid 5 (Ri = CgHs; R2 = H) is readily cyclized to 3 (Ri = CeHs; R2 = H) with excess SOCl2. Ring opening of the imidazo[l,2-¿>] isoquinoline-5,10-diones (3) with alcohols does not occur as readily as that of the more strained 2-aryl-8H-pyrazolo [5,1o]isoindol-8-ones which we recently described.4-6 The latter compounds have some structural similarity to 3. Attempts to cleave 3 (Ri = R2 = H) with MeOH containing traces of methoxide at 25°p roduced recovered 3 on evaporation.6 However, the uv spectrum of 3 in DMF differs from that in MeOH, indicating that the first step in the methanolysis is formation of structure 8.…”

“…The imidazo[l,2-6]isoquinoline-5,10-diones (3) derived from the condensation of equimolar amounts of 0phthaloyl dichloride (1) and an imidazole (2) in the presence of 2 molar equiv of Et3N, react readily with hydrazines R3NHNH2 (R3 = H, alkyl, aryl) to form 4-(2-imidazolyl)phthalazones (4), a new class of compounds. The reactions of these carbonyl reagents differ from those of nucleophiles such as hydroxide ion, alcohols, and amines which attack 3 at the lactam carbonyl group and form the carboxylic acid derivatives (5-7).…”

Anthraquinonoid Vat Dyes

“…The acedianthrone analog (CXXIV) prepared from (CXXV) by condensation with glyoxal sulfate and subsequent fusion with sodium m-nitrobenzenesulfonate in an aluminum O (CXXIV) (CXXV) chloride-sodium chloride melt is a violet vat dye of high affinity. 528,529 During the preparation of (CXXV) from homophthalic acid and o-phenylenediamine, 25% of the isomer is formed and is rejected. 528,529 During the preparation of (CXXV) from homophthalic acid and o-phenylenediamine, 25% of the isomer is formed and is rejected.…”

Condensed isoquinolines. 37.* Heterocyclization using 3-(arylamino)- and 3-(hetarylamino)isoquinolin-1(2H)-ones

“…The condensation of 3-aminoisocarbostyryls substituted at the 3-amino group with aldehydes has been studied previously only in the case of a condensed derivative, namely, benzimidazo[1, 2-b]isoquinolin-11(5H)-one [7,8]. The corresponding alkylidene and arylidene derivatives were obtained by heating a mixture of the reagents in DMF or in acetic acid in the presence of a base.…”