Aryl isothiocyanates, synthesis from

The synthesis of 987 from 985 via 986 has been reported (83S759) by reaction of 985 with aryl isothiocyanates under neutral conditions. The reaction of 4-amino-6-anilino[l,2,4]triazine 988 with methyl iodide and then carbon disulfide gave 989 (90MI3, 90MI9). 

Glutaconaldehyde anion serves as an interesting intermediate for the synthesis of heterocyclic compounds. The parent pyrylium perchlorate has been prepared from glutaconaldehyde and 70% perchloric acid in ether at -55°.° The reaction of glutaconaldehyde anion with alkyl and aryl isothiocyanates and... 

In primary synthesis 2-perimidinamines (660) can be prepared from the naphthalene diamine with bromocyanogen or cyanamide (Scheme 106). 2-Anilino derivatives have been obtained in reactions with aryl isothiocyanates. 2-iV,7V-Dimethylamino derivatives (662) have been obtained via the alkylated amine (661) using dimethylamino(trichloro)methane. Nucleophilic substitution by amine readily occurs in the 2-position when carrying a halo, sulfenyl, or sulfonyl substituent <81RCR816>. 

A general method of synthesis of carbonimidoyl difluorides from alkyl and aryl isothiocyanates was recently described by Sheppard Thus, upon reaction of isothiocyanates with mercuric fluoride, the corresponding carbonimidoyl difluorides were obtained in good yield. The reaction may... 

The combination of alkyl- or aryl-sulphenyl chlorides and trimethylsilyl cyanide in acetonitrile results in complete conversion into the corresponding thiocyanates within one hour at room temperature. This procedure then represents a new synthesis of alkyl or aryl thiocyanates free from isomeric isothiocyanates, from thiols, or from disulphides (Scheme 56). 

Diazo(trimethylsilyl)methyl lithium (3) was found to be the reagent of choice for the synthesis of azoles from heterocumulenes (Scheme 8.43). The reaction is typically carried out in ether at 0-20 °C. Thus, alkyl- (or aryl-)substituted keteni-mines are transformed into 1,2,3-triazoles 188 (246), while C-acceptor-substituted ketenimines yield either 4-aminopyrazoles 189 or 1,2,3-triazoles, depending on the substituents (247). Isocyanates are converted into 5-hydroxy-1,2,3-triazoles 190 (248). Reaction of 3 with isothiocyanates are strongly solvent dependent. 

A one-step procedure for the synthesis of 5-arylimino-l,2,4-thiadiazolin-3-ones (273) from a mixture of alkyl azide, substituted phenyl isothiocyanate and aryl or alkyl isocyanate has been reported (76AG(E)489). Evidence was presented to support the proposal that a... 

N3-Substituted hydantoins and 2-thiohydantoins (9) are prepared by acid-catalyzed cyclization of the substituted ureido or thioureido acids (8) obtained from a reaction of a-amino acids with alkyl or aryl isocyanates and isothiocyanates.1 3,12 This method has been applied to prepare 2-selenohy-dantoins,13 and also in the stereospecific synthesis of (S)-(+)-l,5-cyclotrimethylene-3-phenyl-2-thiohydantoin.14... 

Drach and co-workers described a general synthesis of 2-alkyl(aryl)-5-hydrazino-4-phosphorylated-oxazoles 1640 from 1639 or 1641 (Scheme 1.421). Reactions of 1640 analogs with p-tolualdehyde, p-toluic chloride, and phenyl isothiocyanate gave the expected products. 

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