13142-04-6

Upstream product

• 65423-89-4 triphenylarsazo-p-tolyl 
• 1985-12-2 4-Bromophenyl isothiocyanate 
• 7647-01-0 hydrogenchloride 
• 861312-74-5 (4-bromo-phenyl)-p-tolyl-carbodiimide 
• 622-58-2 p-Tolylisocyanate 
• 106-40-1 4-bromo-aniline 
• 59046-28-5 p-toluoyl-1H-1,2,3-benzotriazole 
• 106-49-0 p-toluidine 
• 2493-02-9 4-bromophenyl isocyanate 
• 99-99-0 1-methyl-4-nitrobenzene 
• 14917-59-0 p-bromobenzoyl azide 
• 51625-31-1 p-Amino-phenylisocyanat 

Relevant academic research and scientific papers

Nitroarenes as versatile building blocks for the synthesis of unsymmetrical urea derivatives and N-Arylmethyl-2-substituted benzimidazoles

In this contribution, a fast and simple method for the synthesis of unsymmetrical urea derivatives and N-arylmethyl-2-substituted benzimidazoles was developed starting from nitroarenes. The reaction of nitroarenes and phenyl isocyanate or phenyl isothiocyanate in tin (II) chloride dihydrate/choline chloride eutectic mixture afforded the expected urea and thiourea derivatives, while the reaction of different aldehydes with o-nitroaniline or 4-methoxy-2-nitroaniline shows a markedly high preference for the obtention of N-arylmethyl-2-substituted benzimidazoles over the 2-substituted analogues. This method offers a straightforward alternative to obtain the target compounds in good to excellent yields with short reaction times employing an operationally simple experimental set-up. Graphic abstract: [Figure not available: see fulltext.] A series of unsymmetrical urea and thiourea derivatives together with 1,2-disubstituted benzimidazoles are easily obtained in good yields starting from nitroarenes employing the eutectic mixture tin (II) chloride dihydrate/choline chloride as reductive reaction media.

An Improved Synthesis of Urea Derivatives from N -Acylbenzotriazole via Curtius Rearrangement

The good leaving tendency of the benzotriazole moiety has been exploited for the synthesis of symmetric, unsymmetric, N -acyl, and cyclic ureas in good yields from N -acylbenzotriazoles by treating the latter with various amines in the presence of TMSN 3 /Et 3 N in a sealed tube. The salient features of the devised protocol includes the high-yield, mild, metal-free, one-pot reaction conditions, and short reaction time. Furthermore, in many cases, no column chromatography is required for the purification.

N - (4 - (3 - amino - 1 H - indazole - 4 - yl) phenyl) - N' - (2 - fluoro - 5 - methylphenyl) urea intermediate preparation method

The invention provides a preparation method of N-(4-(3-amino-1H-indazol-4-yl) phenyl)-N'-(2-fluoro-5-methylphenyl) urea and an intermediate thereof. Specifically, the invention provides a preparation method of a borate ester compound as shown in a formula I, and the preparation method comprises the following steps: enabling a compound as shown in a formula III to react with a compound as shown in a formula IV to generate a compound as shown in a formula V, and enabling the compound as shown in the formula V to react with a boron reagent to generate the compound as shown in the formula I. The method has the characteristics of convenience in reaction, easiness in obtainment of the intermediate, high yield, high product purity of above 98.5%, low cost of raw materials and the like, and is suitable for industrial application.

SYNTHESIS AND REACTIONS OF TRIPHENYLARSINIMINES

Triphenylarsinimines formed in situ from isocyanates and triphenylarsine oxide have been found to react smoothly with carbonyl compounds like aldehydes, quinones and aromatic ketones giving the corresponding Schiff's bases in high yields.In the case of aldehydes, quinones or activated ketones, e.g., α-diketones, only a catalytic amount of triphenylarsine oxide is necessary for the reaction to proceed to completion.Quinones react with particular ease.Thus the previously unknown 9,10-phenanthrenequinone N-phenylimine 12 (R = Ph, Scheme IV) can be prepared in high yield from 9,10-phenanthrenequinone and phenyl isocyanate under catalytic influence of triphenylarsine oxide.Orthoquinones like 9,10-phenanthrenequinone react with vinylic isocyanates, forming monoimines 13 which rearrange to 1,4-oxazines 14 (Scheme V).Diisocyanates react under the catalytic action of triphenylarsine oxide with dialdehydes under mild conditions, forming some interesting new polymers 25, 26 in high yields.Reactions with aliphatic isocyanates give N-alkyl-N'-arylcarbodiimides, whereas reactions with isothiocyanates proceed through intermediates 20 and 21 to mixed carbodiimides 16, 24 and 25. Key words: Triphenylarsinimines; synthesis; reactions; Schiff's bases; unsymmetrical carbodiimides; polymers.