133390-64-4

Upstream product

• 133390-63-3 2-<(Triphenylphosphoranylidene)amino>benzyl Alcohol 
• 2493-02-9 4-bromophenyl isocyanate 
• 20615-76-3 2-azidobenzyl alcohol 
• 5344-90-1 2-Aminobenzyl alcohol 
• 1985-12-2 4-Bromophenyl isothiocyanate 

Relevant academic research and scientific papers

A Facile Synthesis of 2-Aminobenzoxazines Based on Iodine-Catalyzed Desulfurative Cyclization

A facile and environmentally benign access to N-aryl/alkyl-4H-benzoxazin-2-amines is achieved from 1-[2-(hydroxymethyl)phenyl/alkyl]-3-phenylthioureas under transition-metal-free conditions. The conversions occur smoothly in the presence of a catalytic amount of molecular iodine and hydrogen peroxide as the oxidant in tetrahydrofuran at room temperature to afford moderate to good yields (28-90%) of the desired products within 2 hours. This method reports the first examples of the catalytic transformations of 1-[2-(hydroxymethyl)phenyl/alkyl]-3-phenylthioureas into N-aryl/alkyl-4H-benzoxazin-2-amines based on desulfurative cyclization.

One-pot synthesis of five and six membered N, O, S-heterocycles using a ditribromide reagent

In a one-pot procedure, bromine less brominating reagent 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been utilized as an efficient desulfurizing agent for the construction of a library of heterocycles containing N, O, and S starting from aryl/alkyl isothiocyanates. In this approach, aryl/alkyl isothiocyanate reacts with o-phenylenediamine (o-PD), o-aminophenol, and o-aminothiophenol to form their monothiourea which on desulfurization with EDPBT led to the formation of corresponding 2-aminobenzimidazoles, 2-aminobenzoxazoles, and 2-aminobenzothiazoles, respectively. An interesting regioselectivity was observed for unsymmetrical thiourea having a naphthyl moiety on the one side and an ortho amino or an ortho hydroxy phenyl group on the other side giving a completely different product which is mainly dependent on the nature of the nucleophiles (-OH or -NH 2). Further, the bis-thioureas resulted from the aliphatic 1,2-diamine with 2 equiv of aryl isothiocyanates on treatment with EDPBT gave imidazolidenecarbothioamides, whereas bis-thioureas resulted from aromatic 1,2-diamine yielded benzimidazoles with concurrent expulsion of an isothiocyanate unit. This method is simple and applied to various substrates which are amenable to bromination that reveals the desulfurizing ability of EDPBT predominating over its brominating ability. Finally, the spent reagent EDPDB can be recovered, regenerated, and reused without any loss of activity.

Desulfurization mediated by hypervalent iodine(III): A novel strategy for the construction of heterocycles

The desulfurization ability of diacetoxyiodobenzene (DIB) has been explored in the preparation of isothiocyanates from the corresponding dithiocarbamate salts. The in situ generated isothiocyanates reacted with o-phenylenediamine and o-aminophenol to form monothioureas, which, on treatment with a further equivalent of DIB in one pot, gave benzimidazoles and aminobenzoxazoles, respectively. Aliphatic 1,2-diamines on reaction with 2 equiv. of isothiocyanate followed by treatment with DIB gave imidazolidenecarbothioamides, whereas the treatment of aromatic 1,2-diaminebis(thioureas) yielded benzimidazoles with the concurrent formation of isothiocyanate. The driving force for the formation of the latter is the aromatization of the product. The use of DIB makes these methods simpler and more efficient, giving high yields of the desired products in one pot. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

A novel and efficient synthesis of 4H-3,1-benzoxazines by a tandem aza-Wittig/heterocumulene-mediated annulation strategy

2-[(Triphenylphosphoranylidene)amino]benzyl alcohol 2 reacts with isocyanates or isothiocyanates in refluxing toluene to give the corresponding 2-alkyl(aryl)amino-4H-3,1-benzoxazines 5. Iminophosphorane 2 also reacts with carbon dioxide and carbon disulfide to give 4H-3,1-benzoxazin-2(1H)-one (6) and -thione (7), respectively.