Chemistry of 2,4-Diaminothiopyranylium Iodides Syntheses of α,β,γ,δ-Unsaturated Thiocarboxamides

Article abstract of DOI:10.1007/BF00798954

Aminolyses of 4-dialkylamino- and 4-alkylamino-2-methylthiothiopyranyliden iodids 2 resp. under various reaction conditions leads to assymmetrically or symmetrically substituted 2,4-bisamino- or 2,4-bisdialkylamino- and 2-alkylamino-4-dialkylamino- or 2-dialkylamino-4-alkylamino- or 2-amino-4-dialkylaminodihydrothiopyranylium iodides 3, 4, 5, 6 resp.On treatment with alkali 4-alkylamino- and 4-dialkylamino-2-alkylaminothiopyranylium iodides 3, 4 are hydrolysed to the 2-alkylimino-2H-thiopyranes 7. 4-Alkylamino-2-dialkylaminothiopyranylium iodides 5 react with alkali to give three products: the two stereoisomeres 2-dialkylamino-4-alkylimino-4H-thiopyranes 9 A,B and the N,N-substituted α,β,γ,δ-unsaturated thiocarboxamide 10.The hydrolysis of 2,4-bisdialkylaminothiopyranylium iodide 6a leads to the 2-dialkylamino-4H-thiopyran-4-one 11a, the 4-dialkylamino-2H-thiopyrane-2-one 12 and the N,N-substituted unsaturated thiocarboxamide 10d. α,β,γ,δ-unsaturated thiocarboxamides 10 a-c are formed by the reaction of 2-amino-4-dialkylaminothiopyranylium iodides 3 a-c with diluted alkali.By heating with acids 10 a-c are cyclisized to the 2-aminothiopyranylium derivates 3. - Keywords: Alkylaminothiopyranylium iodides; 2-Alkylimino-2H-thiopyranes; 4-Alkylimino-4H-thiopyranes; 2,4-Diaminothiopyranylium iodides; Thiocarboxamides, α,β,γ,δ-unsaturated