The reaction between 3,3-bis(methoxyphenyl)-3H-naphtho[2,1-b]pyran and 1,3-bis(methoxyphenyl)-1H-naphtho[2,1-b]pyran, 2,2-diphenyl-2H-chromen and 2,4-diphenyl-4H-chromen,and related compounds

The reaction between 3,3-bis(methoxyphenyl)-3H-naphtho[2,1-b]pyran and 1,3-bis(methoxyphenyl)-1H-naphtho[2,1-b]pyran under acid conditions gives a 7a,15a-dihydro-7a,15-bis(methoxyphenyl)-16-[2,2-bis(methoxyphenyl)-l-vinyl]dinaphtho-[2,1-b:2,1-g]-4H,5H-pyrano[2,3-b]-pyran.     

Ring-opened Crystal Structure and Photochromism of 2,2-Bis（4-tertiary butyl phenyl）-3H-naphtho[2,1-b]pyran

The title compound, 2,2-bis（4-tertial butyl phenyl） naphthopyran, has been prepared and characterized by means of IR, ^1H NMR and elemental analysis, and its crystal structure was determined with X-ray diffraction in the ring-opened form after hydrolyzation. It belongs to monoclinic, space group P21/c, with a = 14.358（3）, b = 7.6725（15）, c = 24.470（5） А, β= 97.147（4）°, C_33H_36O2, Mr=464.62, V= 2674.8（9）А^3, Z = 4, Dc = 1.154 g/cm^3,μ= 0.070 mm^-1, F（000） = 1000, the final R = 0.0514 and wR = 0.1272 for 5444 observed reflections （I 〉 2σ（I））. X-ray analysis revealed that the C（13）-O（1） bond of the title compound cracks after UV irradiation, the six-membered heterocycles are destroyed, and zwitterionic intermediates come into being. The molecular structure in the ring-opened form is obtained after hydrolyzation. It is infrequent that the single-crystal structure is determined in a ring-opened form. A two-dimensional framework is formed by O-H…O and CAr-H…O hydrogen bonds. The UV-vis spectra show that the title compound exhibits excellent photochromic properties in solutions and polymers.     

A novel 2-C reactivity studies of 1-aroyl-1,2-dihydro-3H-naphtho[2,1-b]pyran-3-ones

The 2-C, methylene group of 1-aroyl-1,2-dihydro-3H-naphtho[2,1-b]pyran-3-ones (2) have been showed to possess a superior reactivity towards many of organic reagents. The naphthopyrones (2) condensed with aromatic aldehydes to give the 2-arylidine derivatives (3). Bromination of 2 gave 1,2-dibromo (4) or 5-bromo (5) derivatives depending on the reaction conditions. The base catalyzed addition or cycloaddition of naphthopyrones (2) to 4-methoxy benzalacetophenone gave the expected Michael adduct (6) or the cyclic adducts (7–9) depending on the type of catalytic base and reaction conditions. Structures of the products have been established by elemental analyses, IR and ¹H NMR spectroscopic methods.     

Transient absorption studies of the photochromic behavior of 3H-naphtho[2,1-b]pyrans linked to thiophene oligomers via an acetylenic junction

The photophysical and photochemical properties of four 3,3-diphenyl-3H-naphtho[2,1- b]pyrans substituted, via an acetylenic junction, to (thiophene) n oligomers (n = 0-3 units) were investigated by transient absorption in the femtosecond to microsecond time domain and by stationary absorption and fluorescence. The decay of the initially produced excited S1(pi pi*) state is found to occur via three competing processes: fluorescence, intersystem crossing, and a ring-opening reaction leading to a colored merocyanine product, with relative yields varying drastically with n. Whereas ultrafast (sub-picosecond) reaction dynamics and high product quantum yield are observed for n = 0 and 1, the reaction is considerably slowed down on going to the n = 2 (105 ps) compound and does not occur for n = 3. A reaction scheme that accounts for this behavior is proposed and the effect of the oligothiophenic chain length on the photoinduced properties is discussed. It is suggested that increasing the chain length from 1 to 3 thiophene units stabilizes the S1(pi pi*) state by pi conjugation and induces an excited-state potential barrier along the reaction pathway.     

Studies on the photochromic mechanism of 1,2-dimethyl-5-phenyl-3-pyrryl succinic anhydride

Photochromism of 1,2-dimethyl-5-phenyl-3-pyrryl fulgide (compound I) has been investigated in various solvents. The photocyclization process of I has been examined by means of nanosecond time resolved absorption spectroscopy; a new transient species was found on the nanosecond time scale. Oxygen can severely quench the new transient species. The photocyclization process is shown to be complicated. Both the excited singlet state and the excited triplet state are involved in the photochromic process.     

Synthesis of 2-phenyl-3-(2-furyl) — and 2-phenyl-3-[β-(2-furyl)vinyl]-1,2-dihydro-naphtho[1,2-d]-1,2,4-triazines

The corresponding 2-phenyl-3-(2-furyl)- and 2-phenyl-3-[-(2-furyl)vinyl]-1,2-dihydronaphtho-[1,2-d]-1,2,4-triazines were obtained by heating Schiff bases [prepared by reaction of 1-(phenyl-azo)-2-aminonaphthalene with furfural, -(2-furyl)acrolein, and their 5-bromo and 5-nitro derivatives] in glacial acetic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 158–160, February, 1973.     

Synthesis of 3a,6,6,9a-tetramethyl-trans-perhydronaphtho [2,1-b]furan and 4a,7,7,10a-tetramethyl-trans-perhydronaphtho [2,1-b]pyran

The compounds 3a,6,6,9a-tetramethyl-trans-perhydronaphtho[2,1-b]furan (ambrox or ambroxide) and 4a,7,7,10a-tetramethyl-trans-perhydronaphtho[2,1-b]pyran (homofixator) — substances important in the perfume industry — have been synthesized by superacid cyclization of E,E-homofarnesol and E,E-bishomofarnesol or mixtures of the isomeric bicyclohomofarnesenes or bicyclobishomofarnesenols. Superacid cyclization of these alcohols was shown to be an effective structurally selective and stereospecific method of obtaining ambroxide and homofixator.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 896–901, July, 1990.     

Pyrylation of 1,2-diphenylbenzo[b]cyclopenta[e]pyran

1,2-Diphenylbenzo[b]cyclopenta[e]pyran was pyrylated with 2,6-diphenylpyrylium perchlorate. The structures of the singly and doubly charged 2,6-diphenyl-4-(1,2-di-phenylbenzo[b]cyclopenta[e]-3-pyrania)pyrylium cations are confirmed by data from the electronic absorption spectra. A radical mechanism for the pyrylation is proposed on the basis of the ESR spectrum.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 459–461, April, 1978.     

cis-3-芳脲基-2-苯基-2-氧代萘并[1,2-d]-1,2-氧膦杂环戊烷合成

利用2-羟基-1-萘甲醛、芳基脲、苯基二氯化膦作为起始原料,在无水甲苯中反应合成cis-3-芳脲基-2-苯基-2-氧代萘并[1,2-d]-1,2-氧膦杂环戊烷.产物结构经IR,1HNMR,31PNMR和元素分析等进行了表征.     

A facile synthesis of 1-alkylthio and acylthio-2,3-dihydro-1H-naphtho[2,1-b]thiopyrans and 4-alkylthio and acylthio-3,4-dihydro-2H-naphtho[1,2-b]thiopyrans

The reaction of 3-(2-naphthylthio)propionaldehyde ( 3 )and its (1-naphthylthio)isomer (7)with a variety of thiols and thio acids in the presence of sulfuric acid at room temperature afforded 1-alkylthio and acylthio-2,3-dihydro-1H-naphtho[2,1-b]thiopyrans 5 and 4-alkylthio and acylthio-3,4-dihydro-2H-naphtho[1,2-b]thiopyrans 9 in excellent yield.     

Iron-mediated [3 + 2] or [3 + 3] annulation of 2-(2-(ethynyl)phenoxy)-1-arylethanones: selective synthesis of indeno[1,2-c]chromenes and 5H-naphtho[1,2-c]chromenes

An iron-mediated tandem annulation strategy has been developed for the synthesis of numerous functional indeno[1,2-c]chromenes and 5H-naphtho[1,2-c]chromenes. This work is the first to disclose an iron-mediated method through sequential electrophilic addition of a ketone to an alkyne and annulation tandem reaction. Importantly, a halide is introduced into the products by a ring-opening process among the annulation of alkynylcyclopropanes, which makes the methodology more attractive for organic synthesis.     

Synthesis of 2-aryl-3H-naphtho[1,2-d]imidazoles containing an adamantane fragment

N ²-[1-(1-Adamantyl)alkyl]naphthalene-1,2-diamines reacted with benzoyl chlorides in chloroform in the presence of triethylamine to give N-{2-[1-(1-adamantyl)alkylamino]naphthalen-1-yl}benzamides which underwent intramolecular cyclization to 2-aryl-3H-naphtho[1,2-d]imidazoles on heating in toluene in the presence of p-toluenesulfonic acid. 3-[(1-Adamantyl)methyl]-2-(3-nitrophenyl)-3H-naphtho[1,2-d]imidazole was synthesized from N ²-[(1-adamantyl)methyl]naphthalene-1,2-diamine and 3-nitrobenzaldehyde.     

2-氨基-3-氰基-4-芳基-6-甲氧基-1,4,9,10-四氢萘并[2,1-b]吡喃衍生物的一步合成

以芳醛、丙二腈和7-甲氧基-1,2,3,4-四氢萘-2-酮为原料,在六氢吡啶催化下以乙醇为溶剂,在室温合成了一系列新的2-氨基-3-氰基-4-芳基-6-甲氧基-1,4,9,10-四氢萘并[2,1-b]吡喃衍生物,反应条件温和,产率较高,并通过IR,1H NMR和元素分析表征产物的结构,还通过单晶X射线衍射分析确证产物的构象.     

Symthesis of 3-[1-(p-Fluorophemyl)-Pyrazol-3-YL]-Quimoxalimomes

Abstract

3-[1-(p-Fluorophenylhydrazono)-L-threo-2,3,4-tri hydroxybutyl1-2-quinoxalinowe was prepared and trarrsformed to 3-[5-acetoxymetnyl-1-(p-fluorophenyl)-pyrazol-3-yl]-2-quinoxalinone. N-methylation, followed oy dehydrative cyclisation, gave the M-methyl-derivative of the latter pyrazole. Periodate oxidation gave a glyoxalyl derivative whose aldehyde functionality was confirmed by reduction and oximation.     

Room temperature photochromic liquid crystal [3H]-naphtho[2,1-b]pyrans-photochromism in the mesomorphic state

Photochromic liquid crystals based on [2H]-chromenes functionalised in the 3,3[prime or minute]-positions by phenyl groups linked to 4-cyano-4[prime or minute]-hydroxybiphenyl groups via alkyl and siloxane spacers as chromophore were synthesised and the photochromic and mesomorphic behaviour was investigated.     

DDQ induced oxidative cyclisations of 1,2-dihydronaptho[2,1-b]furans

The DDQ mediated oxidative cyclisation reactions of a series of dihydronaptho[2,1-b]furans were examined. In the presence of an acid catalyst, the reaction yielded polycyclic ethers and lactones in good to excellent yields.