Spiropyrans and spirooxazines 5. Synthesis of photochromic 8-(4,5-diphenyl-1,3-oxazol-2-y1)-substituted spiro[indoline-benzopyrans]

Photochromic spiro[indoline-benzopyrans] containing 4,5-diphenyloxazolyl group at position 8 of the benzopyran fragment have been obtained. New diphenyloxazolyl-substituted spiropyrans manifest considerably higher thermal stability of the merocyanine isomers than their naphthopyran analogs.     

Spiropyrans and spirooxazines

The Duff formylation of 5-bromo- or 5-chloro-8-hydroxyquinoline leads to the corresponding 7-formyl derivatives, condensation of which with 2-methyleneindolines or 3H-indolium halides in the presence of a base afforded new photochromic 6′-halo-substituted spiro[indoline-2,2′-2H- pyrano[3,2-h]quinolines]. Thermal and photo-induced isomerization of compounds obtained have been investigated by 1H NMR and UV spectroscopy.     

Spiropyrans and spirooxazines 9. Photochromism of novel cationic spirooxazines

Novel photochromic spirooxazinoquinolines, their cationic derivatives, and cationic spirooxazine containing pyridinium cation in the aliphatic side chain of the oxazine moiety of the molecule were synthesized. Quaternization of the quinoline fragment leads to a substantial increase in the thermal stability of the merocyanine isomers of cationic spirooxazines and a decrease in the efficiency of photocoloration. Pyridinium cation in the aliphatic side chain of the spirooxazine does not exert a substantial effect on the kinetics of photocoloration and thermal bleaching.     

Spiropyrans and spirooxazines 7. Novel spirobipyrans and their cationic derivatives

Novel photochromic spirobipyrans containing the dimethylamino group in position 7 of the benzopyran moiety and their cationic derivatives with the trimethylammonium substituent exhibiting no photochromic properties were synthesized.     

Spiropyrans and spirooxazines. 2. Synthesis,structures, and photochromic properties of 6"-cyano-substituted spironaphthooxazines

A series of 6"-cyano-substituted spiro[indoline-2,3"-naphtho[2,1-b]oxazines] containing substituents with carbon chains of different lengths in the indoline fragment were synthesized. The structure of one of these spironaphthooxazines was established by X-ray diffraction analysis. The influence of substituents on the photochromic properties of the resulting compounds in solutions and polymeric films was studied.     

Spiropyrans and spirooxazines. 1. Synthesis and photochromic properties of 9"-hydroxy- and 9"-alkoxy-substituted spironaphthooxazines

A procedure was developed for phase-transfer catalyzed alkylation of 5-hydroxyindolenine and 9"-hydroxy-substituted spiro[indoline-2,3"-naphtho[2,1-b]oxazines] by alkyl halides. New 9"-hydroxy- and 9"-alkoxy-substituted spironaphthooxazines, spirooxazinyloxyacetic acids, and their esters containing substituents with different length of the carbon chain in the indoline moiety were synthesized. The influence of the substituents on the spectroscopic properties of the starting and colored forms and the kinetic characteristics of photochromic transformations of 9"-substituted spironaphthooxazines in solutions and polymeric films was investigated. The bipolar merocyanine forms of spirooxazines were found to produce H-aggregates.     

Synthesis of spiro[benzopyrazolonaphthyridine-indoline]-diones and spiro[chromenopyrazolopyridine-indoline]-diones by one-pot, three-component methods in water

The synthesis of spiro[benzo[h]pyrazolo[3,4-b][1,6]naphthyridine-7,3′-indoline]-2′,6(5H)-diones and spiro[chromeno[4,3-b]pyrazolo[4,3-e]pyridine-7,3′-indoline]-2′,6(6aH,10H)-diones via a one-pot, three-component reaction of 4-hydroxycoumarin or 4-hydroxy-1-methylquinolin-2(1H)-one, isatins and 1H-pyrazol-5-amines in water is reported.     

Synthesis of spiro thiopyrano[2,3-d]thiazolidines

Spiro thiazolidine rings 3a,b are obtained in excellent yields by one-pot reaction of 1a,b with Lawesson reagent via [4 + 2] cycloaddition; the X-ray crystallography structure for compound 3a was determined and documented     

Synthesis of acenaphtho[1,2-x]heterocycles and spiro[acenaphthylene 1-isoxazoles]

Methyl (Z)-(1,2-dihydro-2-oxo-1-acenaphthylenylidene)acetate 1 gives with hydroxylamine the oximes 2 and the pyrrole derivative 4 , whereas with hydrazines affords the pyridazinones 5 and 6 . A pyridazine derivative 8 is also isolated from the reaction of (1,2-dihydro-2-oxo-1-acenaphthylenylidene)acetone 7 with hydrazine hydrate. Reaction between the spiro-derivative 9 and hydroxylamine hydrochloride gives oxime 10 , whereas Wittig olefination of 9 with ylide 11 yields compound 12 which by reaction with 2,4,6-trimethylbenzonitrile oxide ( 13 ) affords the dispiro-derivatives 14 . Finally from the reaction of acenaphthylene-1,2-quinone ( 17 ) with the bisylide 16 the acenaphtho[1,2-c]thiophene ( 18 ) is formed.     

Synthesis and cation complexation of calix[4]azacrowns and a spirobiscalix[4]azacrown

The synthesis and complexation properties of three new derivatives, one spirobiscalix[4]azacrown (1) and two calix[4]azacrown (2 and 3), are reported. Complexation studies of the three ligands toward transition and heavy metal cations have been carried out and monitored by UV absorption spectrophotometry in acetonitrile. Mononuclear complexes were detected for all complexes, whereas binuclear species (M₂L) were also formed in the case of ligand 1 with Cu²⁺ and Pb²⁺. The extraction properties of 1, 2 and 3 toward Cu²⁺, Zn²⁺, Pb²⁺, Ag²⁺ and Cd²⁺ are also reported. The results showed that complexation is the main factor affecting extraction with ligands 2 and 3, while with ligand 1 it is not.     

Synthesis of homochiral spiro[4.4] nonane-1,6-diols

Homochiral cis,cis-; cis,trans- and trans,trans-spiro[4.4]nonane-1,6-diols were prepared via diastereoselective reduction of enantiomerically pure spiro[4.4]nonane-1,6-dione (1) with the corresponding reducing agents: lithium n-butyldiisobutylaluminium hydride for cis,cis-diol (2) with 88% yield; BH3·THF for cis, trans-diol (3) with 91% yield; LiAlH4 for trans,trans-diol (4) with 15% yield.     

Synthesis of spiro[indole-3,3′-[1,3,4]thiadiazino[3,2-a]benzimidazoles] and spiro[indole-3,6′-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines]

A method for annulation of the tetrahydrothiadiazine ring to benzimidazoles and 1,2,4-tri-azoles was developed. A number of earlier unknown [1,3,4]thiadiazino[3,2-a]benzimidazoles and triazolo[3,4-b][1,3,4]thiadiazines were obtained as spiro compounds with the oxindole fragment. According to NMR and X-ray diffraction data, the formation of the tetrahydrothiadiazine ring is a diastereospecific process.     

Studies in spiroheterocycles. Part XVII. synthesis of novel fluorine containing spiro[indole-pyranobenzopyran] and spiro[indenopyran-indole] derivatives

An elegant one-step synthesis of two novel spiro ring systems viz: spiro[3H-indole-3,4′-(2′-amino-3′-carbonitrile-[4′H]-pyrano[3,2-c]benzopyran)]-2,5′(1H)-dione8 and spiro[(2-amino-3-carbonitrile-indeno[1,2-b]pyran)-4(5H)>3′-[3H]indole]-2′,5(1′H)-diones in 80–85% yields is described. The spiro heterocycles were prepared by the reactions of fluorine containing 3-dicyanomethylene-2H-indol-2-ones with 4-hydroxy-2H-1-benzopyran-2-one and 1H-indene-1,3(2H)-dione respectively. The synthesized compounds have been characterized on the basis of elemental analyses, ir, pmr, ¹⁹F nmr and mass spectral data.     

Studies in alkylation. I. Synthesis and reactions of spiro[oxirane-2,4-piperidines]

Spiro[oxirane-2, 4′-piperidines] have been prepared by the action of dimethyloxosulfonium methylide on 4-piperidones. The spiro[oxirane-2,4′-piperidines] act as alkylating agents to introduce (4-hydroxy-4-piperidyl) methyl moieties onto heteroaromatic compounds such as 4(3H)-quinazolone.     

Synthesis of homochiral spiro [4.4]nonane-l,6-diols

Homochiral cis, cis-; cis,trans and trans,trans-spiro[4,4]-nonane-1,6-diols were prepared via diastereoselective reduction of enantiomerically pure spiro[4.4]nonane-l,6-dione (1) with the corresponding reducing agents: lithium n-butyldiisobutylaluminium hydride for cis,cis-diol (2) with 88% yield; BH₃·THF for cis, trans-diol (8) with 91% yield; LiAlH₄ for trans,trans-diol (4) with 15% yield.