892723-85-2Relevant academic research and scientific papers
Ph3P/I2-mediated synthesis of N,N′,N″-substituted guanidines and 2-iminoimidazolin-4-ones from aryl isothiocyanates
Wangngae, Sirilak,Pattarawarapan, Mookda,Phakhodee, Wong
, p. 10331 - 10340 (2018/05/31)
A convenient one-pot procedure for the synthesis of acyclic and cyclic guanidines mediated by the Ph3P/I2 system is described. Sequential condensation of aryl isothiocyanates with amines followed by dehydrosulfurization and guanylation could lead to both symmetric and unsymmetric N,N′,N″-substituted derivatives. Through a tandem guanylation-cyclization, a series of 2-iminoimidazolin-4-ones could also be prepared in good yields from the reaction of aryl isothiocyanates with amino acid methyl esters.
Cu(ii) catalysed chemoselective oxidative transformation of thiourea to thioamidoguanidine/2-aminobenzothiazole
Sahoo, Santosh K.,Khatun, Nilufa,Gogoi, Anupal,Deb, Arghya,Patel, Bhisma K.
, p. 438 - 446 (2013/04/10)
2-Haloaryl-sec-alkyl unsymmetrical thioureas (Tu) (halo = -F, -Cl) with a catalytic amount of Cu(ii) salt get oxidised in situ to their disulfide intermediates followed by an imine-disulfide rearrangement to give thioamidoguanidino (Tag) moieties at room temperature. During this process Cu(ii) gets reduced to Cu(i) and forms a complex with the Tag moiety from which Tag moiety can be isolated upon treatment with ammonia. However, when the same reaction was performed at an elevated temperature with a catalytic quantity of Cu(ii) salt, Tu bearing o-halogens (-F, -Cl) gave 2-aminobenzothiazoles via a dehalogenative heteroarylation path and not by the Hugerschoff path involving an electrophilic substitution reaction. For thioureas containing reactive ortho halogens (such as -Br, -I) the reaction proceeds at room temperature giving 2-aminobenzothiazoles via a dehalogenative path requiring a catalytic quantity of Cu(ii). No transformation of thiourea (Tu) to Tag was observed with Cu(i) salts suggesting the requirement of an oxidising Cu(ii) salt for this oxidative transformation. Mild reaction conditions, environmentally benign reagents and solvent, high yields, tolerance of various functional groups are some of the essential features of this methodology.
Arylthioureas with bromine or its equivalents gives no 'Hugerschoff' reaction product
Yella, Ramesh,Murru, Siva,Ali, Abdur Rezzak,Patel, Bhisma K.
experimental part, p. 3389 - 3393 (2010/08/22)
The in situ generated aryl-alkyl unsymmetrical thiourea obtained by the reaction of an aryl isothiocyanate with an aliphatic secondary amine on treatment with bromine or its equivalent gave exclusively a product having a thioamido guanidino moiety and not the expected Hugerschoff product 2-aminobenzothiazole. A plausible reaction mechanism has been proposed for this unprecedented transformation and the scope has been extended to various substrates. The Royal Society of Chemistry 2010.
