Hinsberg synthesis

The Hinsberg synthesis of thiophene derivatives describes the original condensation of diethyl thiodiglycolate and a-diketones under basic conditions which provides 3,4-disubstituted-thiophene-2,5-dicarboxylic acids upon hydrolysis of the crude ester product with aqueous acid. ... 

Finally, the Hinsberg synthesis has been extended to the use of a-aryl-a-carboethoxydimethyl sulfide in conjunction with a series of 1,2-dicarbonyl compounds. Specifically, the 4-nitroaryl substituent provides for sufficient activation of the a-proton to allow condensation and ring closure. These examples appear general and suggest future opportunities for the Hinsberg thiophene protocol. 

Hinsberg synthesis and 1,3-dipolar cycloaddition of thiocarbonyl ylides with dipolatophiles are typical thiophene syntheses in this class (Equation 37). 

Hinsberg synthesis of thiophene derivatives. Formation of thiophene carboxylic acids from a-diketones and dialkyl thiodiacetate. 

Dicarbonyl compounds can be made to cyclize with esters of 3-thiapentanedioic acid 21 under base catalysis (Hinsberg synthesis). This widely applicable and high-yield synthesis leads to substituted thiophene dicarboxylic esters 22 via a double aldol condensation, with the two CH2 groups of 21. Hydrolysis and decarboxylation of the esters yield 3,4-disubstituted thiophenes 23 [23] ... 

The classical Hinsberg synthesis of thiophenes has been applied to the preparation of 2,5-dicarbonylselenophenes (68) <87H(26)909> as shown in Equation (22). 

Mullins, R. J. Williams, D. R. Hinsberg Synthesis of Thiophene Derivatives. InName Reactions in Heterocyclic Chemistry, Li, J. J., Corey, E. J., Eds. Wiley Sons Hoboken, NJ, 2005, pp 199-206. (Review). 

Hinsberg Synthesis of Thiophene Derivatives Hiyama (see Nozaki-Hiyama Coupling Reaction) Hoch-Campbell Aziridine Synthesis Hoesch (see Houben-Hoesch Reaction)... 

A similar conception underlies the Hinsberg synthesis of secondary amines in which the anion of a sulphonamide is alkylated , and the amine obtained by hydrolysis (reaction 50). Mono- and dialkylation... 

Hammick reaction 705 Hinsberg synthesis of amines 54 Hofmann elimination, eis elimination 415... 

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