Alkylation of 3-substituted 5-(2-hydroxyphenyl)-1H-1,2,4-triazoles with chloroacetonitrile gave hitherto unknown N-cyanomethyl derivatives whose structure was determined by X-ray analysis and 1 H and 13 C NMR spectroscopy. Condensation of substituted [3-(2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl]acetonitriles at the activated methylene group with acetone led to the formation of new 3-methyl-2-triazolylbut-2-enenitrile derivatives.Scheme 1.

A two-step approach towards the synthesis of imidazo[1,2-a]indoles from 2-chloroindole-3-carbaldehyde has been developed. It comprises the N-alkylation of indole ring by 2-bromo-1,1-diethoxyethane followed by a treatment with aromatic amine hydrochlorides. The reaction proceeds as a nucleophilic substitution of the chlorine atom at position 2 of the indole ring followed by cyclization along with the condensation at the aldehyde group. Imidazo[1,2-a]indoles were isolated as protonated Schiff bases. Their structure was proved by 1 H and 13 C NMR spectroscopy and X-ray structural analysis.

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The structures of new oxaindane spiropyrans derived from 7-hydroxy-3',3'-dimethyl-3'H-spiro[chromene-2,1'-isobenzofuran]-8-carbaldehyde (SP1), namely N-benzyl-2-[(7-hydroxy-3',3'-dimethyl-3'H-spiro[chromene-2,1'-isobenzofuran]-8-yl)methylidene]hydrazinecarbothioamide, C(27)H(25)N(3)O(3)S, (I), at 120 (2) K, and N'-[(7-hydroxy-3',3'-dimethyl-3'H-spiro[chromene-2,1'-isobenzofuran]-8-yl)methylidene]-4-methylbenzohydrazide acetone monosolvate, C(27)H(24)N(2)O(4)·C(3)H(6)O, (II), at 100 (2) K, are reported. The photochromically active C(spiro)-O bond length in (I) is close to that in the parent compound (SP1), and in (II) it is shorter. In (I), centrosymmetric pairs of molecules are bound by two equivalent N-H...S hydrogen bonds, forming an eight-membered ring with two donors and two acceptors.

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