title: Variations in product in reactions of naphthoquinone with primary amines.
abstract: Reaction of 1,2-naphthoquinone with primary amines gives a 2-amino-1,4-naphthoquinone derivative which is equivalent to 1,2 to 1,4 carbonyl transposition. For example the reaction of 1,2-naphthoquinone with 4-methoxyaniline gives 2-(4-methoxyanilino)-naphthoquinone-1,4-(4-methoxyanil) (1) and with n-butylamine gives 2-(butylamino)-naphthoquinone-1,4-butylimine (2) respectively. The compounds 1 and 2 are characterized by X-ray crystallography; they have hydrogen-bonded dimeric structures. Similar reaction of 1,4-naphthoquinone with 3-picolylamine and 4-picolylamine gives the corresponding 2-amino 1,4-naphthoquinones; two products are characterized by X-ray crystallography. The reaction of 1,4-naphthoquinone with 4-aminothiophenol and 1,4-naphthoquinone with 4-aminophenol are compared. The former leads to C-S and the latter to C-N bond formation. The reaction of 1,4-naphthoquinone with 4-aminothiophenol in an NMR tube is studied to explain that 2-(4-anilinothiolato) 1,4-naphthoquinone derivative to be the sole product in the reaction.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039 Assam, India. w.singh@iitg.ernet.in
authors.forename: Marjit W
authors.initials: MW
authors.lastname: Singh
authors.forename: Anirban
authors.initials: A
authors.lastname: Karmakar
authors.forename: Nilotpal
authors.initials: N
authors.lastname: Barooah
authors.forename: Jubaraj B
authors.initials: JB
authors.lastname: Baruah