107167-60-2

Upstream product

• 110-91-8 morpholine 
• 1985-12-2 4-Bromophenyl isothiocyanate 
• 622-59-3 1-isothiocyanato-4-methylbenzene 
• 106-40-1 4-bromo-aniline 
• 463-71-8 thiophosgene 
• 107167-54-4 N-(p-bromophenyl)-N',N-dicarbomethoxyguanidine 

Downstream Products

• 1237747-28-2 N-((E)-(4-bromophenylimino)(morpholino)methyl)-N-(4-bromophenyl)morpholine-4-carbothioamide 
• 863001-17-6 4-(6-bromobenzo[d]thiazol-2-yl)morpholine 
• 1421761-47-8 C₂₂H₂₄Br₂N₄O₂S 

Relevant academic research and scientific papers

Cu(ii) catalysed chemoselective oxidative transformation of thiourea to thioamidoguanidine/2-aminobenzothiazole

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.

A ligand free copper(II) catalyst is as effective as a ligand assisted Pd(II) catalyst towards intramolecular C-S bond formation via C-H functionalization

Copper(I) catalysts are usually ineffective on the other hand Pd(II) catalysts are quite effective in promoting intramolecular sp2 C-H functionalization (C-S bond formation). Herein, we have developed a ligand assisted Pd(II) catalyzed C-S bond formation via C-H activation from arylthioureas leading to the formation of 2-aminobenzothiazoles for substrates bearing electron donating (EDG) groups in the aryl ring. However without the assistance of ligand this Pd(II) catalyzed reaction is quite unproductive particularly for thioureas possessing strongly electron donating groups in the aryl rings. Interestingly, the ligand free Cu(II) catalyzed oxidative cyclization of arylthioureas are equally effective both for arylthioureas possessing electron donating as well as electron withdrawing groups in the aryl rings.

Tandem regioselective synthesis of tetrazoles and related heterocycles using iodine

A one-pot, tandem process has been developed for the synthesis of a library of tetrazoles from aryl isothiocyanates. Condensation of aryl isothiocyanates with ammonia, and aryl amines (R-NH2) provided mono, 1,3-disubstituted symmetrical and unsymmetrical thioureas, which on desulfurization with molecular iodine (I2) led to formation of the corresponding heterocumulene (cyanamides or carbodiimides). The in situ generated heterocumulene on subsequent treatment with sodium azide at room temperature gave corresponding tetrazoles. The product regioselectivity for unsymmetrical 1,3-disubstituted thioureas was found to be correlated with the basicities (pKa's) of the parent amines attached to the thiourea. Aryl-sec-alkyl unsymmetrical thioureas gave thioamido guanidino products rather than the 5-aminotetrazoles produced by HgCl2 mediation of the reaction. Bis-thioureas derived from aryl isothiocyanates and hydrazine gave thiadiazoles exclusively.

Arylthioureas with bromine or its equivalents gives no 'Hugerschoff' reaction product

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.

Fragmentation of N-aryl- and N-Aralkyl-N',N"-dicarbomethoxyguanidines with Thiophosgene

N-Aryl- and N-aralkyl-N',N"-dicarbomethoxyguanidines (3) on treatment with thiophosgene undergo fragmentation to yield N,N'-dicarbomethoxyurea (5) and the isothiocyanates.