Hydrochloric Acid → HCID 12096470, compound

Participants

Reaction Steps

3-acetylaniline (6.76 g, 50 mmole) in ethanol (50 mL) was treated with methyl isothiocyanate (3.42 mL, 50 mmole). After stirring 18 hr at room temperature, the crystalline N-(3-acetylphenyl)-N′-methylthiourea product was filtered out (7.75 g, 75% yield, mp 119-120° C.). This thiourea (3.5 g, 16.8 mmole) was combined with 2-methylnaphthoquinone (5.8 g, 33.6 mmole) in 35 mL ethanol in the presence of 12N aq. HCl (1.4 mL, 16.8 mmole). After 24 hr, filtration and washing with ethanol, ethyl acetate and ether and air drying gave 2-(3-acetylphenyl)amino-1,4-dimethyl-5-hydroxynaphtho[1,2-d]thiazolium chloride (1.62 g, 24%). This keto naphthothiazolium salt (0.80 g, 2.0 mmole) was heated at reflux in 80% methanol (12 mL) containing aminoguanidine hydrochloride (0.24 g, 2.2 mmole) for 40 hr and allowed to cool. Filtration 0.80 g off-white powder. Recrystallization of 0.75 g from methanol gave 0.42 g 2-[[3-[1-[2-(aminoiminomethyl)hydrazono]ethyl]phenyl]amino]-4-methylnaphtho[1,2-d]thiazol-5-ol as a pale yellow powder, mp 252-257° C. (dec.).

Provenance & Evidence