3201-53-4

Upstream product

• 16486-25-2 1-benzoyl-3-methyl-thiourea 
• 74-89-5 methylamine 
• 4461-33-0 benzoyl isocyanate 
• 98-88-4 benzoyl chloride 
• 598-50-5 N-Methylurea 
• 89879-85-6 2-methyl-5-phenyl-1,2,4-thiadiazol-3(2H)-one 
• 108-86-1 bromobenzene 
• 201230-82-2 carbon monoxide 
• 1622923-36-7 (ethylthiotrifluoroborate)methane dimethyliminium zwitterion 
• 98-80-6 phenylboronic acid 
• 532-55-8 Benzoyl isothiocyanate 
• 5378-17-6 3-hydroxy-5-phenyl-1,2,4-thiadiazole 
• 7746-72-7 N¹-benzoyl-N³-cyanoguanidine 
• 27182-54-3 5-phenyl-1,2,4-thiadiazol-3-amine 

Relevant academic research and scientific papers

Catalytic Synthesis of Potassium Acyltrifluoroborates (KATs) from Boronic Acids and the Thioimidate KAT Transfer Reagent

We report the synthesis of potassium acyltrifluoroborates (KATs) by a palladium-catalyzed cross-coupling of boronic acids and the thioimidate KAT transfer reagent. The combination of widely available aryl- and vinylboronic acids with commercially available thioimidate 1 using catalytic PdII and a CuII additive enables the preparation of KATs in high yields and with good functional group tolerance. This formal insertion of CO into organoboronic acids can also be applied to boronic acid pinacol esters and potassium organotrifluoroborates using a slightly modified procedure. The cross-coupling can be telescoped into the one-pot synthesis of amides and α-aminotrifluoroborates by exploiting the unique chemistry of KATs and their trifluoroborate iminium (TIM) derivatives.

New synthesis of aryl and heteroaryl N-acylureas via microwave-assisted palladium-catalysed carbonylation

A new, practical synthesis of aryl and heteroaryl N-acylureas has been developed via palladium-catalysed carbonylation of aryl or heteroaryl halides in the presence of urea nucleophiles. A range of reactions illustrating the wide scope of this reaction was carried out under microwave irradiation, using either carbon monoxide gas in a vessel equipped with a gas inlet adapter, or molybdenum hexacarbonyl as the carbon monoxide source in standard microwave vials. The reactions proceeded in good to excellent yields. To illustrate the usefulness of this method a one-step synthesis of the important insecticide diflubenzuron is reported.

Decomposition of N′-benzoyl-N-nitrosoureas in aqueous media

The decomposition of N′-benzoyl-N-methyl-N-nitrosourea (BMNU) in aqueous media over the 0-14 pH range has been studied. In basic and neutral media (6 a = 7.8) and subsequent decomposition of the conjugate base of the thus formed nitrosourea, via an intermediate benzoyl isocyanate. Support for this mechanism is provided by the presence of N,N′-dibenzoylurea in the final reaction mixtures, as the result of the trapping of benzoyl isocyanate with benzamide generated from hydrolysis of the former. The hydrolysis of BMNU takes place through three competitive pathways: spontaneous decomposition of the conjugate base of BMNU, and buffer-catalyzed and hydroxide ion catalyzed water addition to the carbonyl group of the deprotonated nitrosourea. N′-Benzoyl-N,N′-dimethyl-N-nitrosourea (BDMNU), a benzoyl nitrosourea lacking the acidic proton of BMNU, is hydrolyzed in basic media by attack of hydroxide ion on the carbonyl group of the urea. In acid media (0 pH 6), BMNU gives only deamination products, differing from the reported behavior of other N-nitroso compounds and of the isoster nitrosoguanidine, in which denitrosation is almost quantitative. The reaction is acid-catalyzed in the 0-2.5 pH range and pH-independent in the 3-5 pH range. The presence of general acid catalysis (a = 0.60), the absence of nucleophilic catalysis, and the thermodynamic activation parameters for the reaction support the mechanism proposed in the literature for the deamination of N-nitrosoureas in acidic media. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.

1,3-Dipolar cycloadditions to (5Z)-1-Acyl-5-(cyanomethylidene)-imidazolidine-2,4-diones: Synthesis and transformations of spirohydantoin derivatives

Cycloadditions of various 1,3-dipoles to (5Z)-1-acyl-5-(cyanomethylidene)-3-methylimidazolidine-2,4-diones 8 or 9, prepared in 3 steps from hydantoin (1) (Schemes 1 and 2), were studied. In all cases, reactions proceeded regio- and stereoselectively. The type of product depended on the 1,3-dipole and/or dipolarophile employed as well as on reaction conditions. Thus, with stable dipoles under neutral conditions, spirohydantoin derivatives 12-16 were obtained (Scheme 2), while under basic or acidic conditions, pyrazole- or isoxazole-5-carboxamides 18 and 23-26 and carboxylate 27 were formed via aromatization of the newly formed dihydroazole ring, followed by the simultaneous cleavage of the hydantoin ring (Schemes 3-5).

Cyclic Meso-ionic Compounds. Part 23. Novel Chemistry of 1,2,4-Thiadiazoles and Their Transformation into Meso-ionic 1,2,4-Thiadiazolium Derivatives

Representatives of two new classes of meso-ionic heterocycles have been synthesised, the 1,2,4-thiadiazolium-3-olate (8) and the 1,2,4-thiadiazolium-3-tosylaminide (25).The reactions of 1,2,4-thiadiazoles and nucleophiles follow two general pathways: (i) reductive transformation to N-thiobenzoyl derivatives and (ii) elimination of elemental sulphur and the formation of N-benzoyl derivatives.A mechanistic rationale is proposed for the operation of pathways (i) and (ii).Earlier views on the oxidative formation of certain 1,2,4-thiadiazoles are corrected.A novel synthetic route to heterocycles containing sulphur-nitrogen bonds is described. 1,2,4-Thiadiazoles are formed by oxidation of N-thiobezoylureas and N-thiobenzoylguanidines by bis(4-methoxyphenyl) telluroxide.