Dithioformic acid synthesis

The formamides 16 are intermediates. Formamide (Bredereck variant of the Traube synthesis [149]), formamidine, orthoformic ester, diethoxymethyl acetate, Vilsmeier reagent (fi om DMF and POCI3) and dithioformic acid are used as formic acid derivatives. 4,5-Diaminopyrimidines can be obtained from 4-aminopyrimidines 17 by nitrosation with HNO2 followed by reduction of the nitroso compounds 18 ... 

Synthesis.— In an attempt to synthesize dithioformic acid by the action of dilute hydrochloric acid on potassium dithioformate (the product of the reaction between chloroform and potassium sulphide ), Gattow and Engler obtained a material consisting mainly of trimeric dithioformic acid. Recently, the same workers have also shown that the polymer of monothioformic acid in aqueous potassium hydroxide may undergo disproportionation, yielding equal amounts of formate and dithioformate anions. 

Amino-4-naphthyl-5(p-aminophenyl) thiazoles, synthesis of, 230 orAminonitriles, condensation, with salts or esters of dithioformic and dithio-phenacetic acids, 284... 

Two further reactions might be included here, since they involve modification at both carbon and sulphur. In the first reaction, dehydration of the sulphoxides 388 (R = Me or aryl R = H, Me, ethenyl or Ph) to the diethyl [(l-alkylthio)alk-l-enyl]phosphonates 389 is said to result following the action of trimethylsilyl trifluoromethanesulphonate The second reaction constitutes a new and improved synthesis of an ester of (mercap-tomethyl)phosphonic acid, and consists in the treatment of methyl (diisopropylphosphi-noyl)dithioformate with NaBH4. ... 

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