Indan-1,3-dione, reaction with

In this reaction, k0 for benzylidene-substituted Meldrum s acid is higher than for benzylidenemalononitrile log [fc0(CN)2/fc0XY] —0.7, while for benzylidene-l,3-indandione, k0 is about the same as for the malononitrile derivative (19). This finding contrasts with the normal behavior where k0 for benzylidene-substituted Meldrum s acid and benzylidene-l,3-indan-dione should be much lower than that for benzylidenemalononitrile (Table III). 

The second approach B has also emerged as competent way to build the spiro system. As a typical example, Julia s approach [60] has been discussed. The coupling reaction of indene with 2,3-his(bromomethyl)-l,4-dimethoxyben-zene followed by oxidation gave rise to the spiro derivative 72. The inherent drawback of this approach is five step sequence necessitated for transforming 71 into 72 (Scheme 10). A similar protocol was used for the coupling reaction by Ayyangar et al. [61] with the exception that phthalylchloride was used which directly provided the 1,3-indane dione system (Scheme 11). 

Ninhydrin (also named 1 2 3-triketoindane or 1 2 3-triketohydrindene hydrate) is prepared most simply from the inexpensive phthahc anhydride (I). The latter is condensed with acetic anhydride In the presence of potassium acetate to give phthalylacetlc acid (II) reaction of the latter with sodium methoxide in methanol yields 1 3-indanedionecarboxyhc acid, which is decomposed upon warming with dilute hydrochloric or sulphuric acid to indane-1 3-dione (or 1 3-diketohydrindene) (HI). Selenium dioxide oxidation of (III) afibrds indane-1 2 3-trione hydrate (ninhydrin) (IV). 

Reaction of 2,3-dichloro-1,4-naphthoquinone with one equivalent of the anion of indane-1,3-dione at room temperature gave an excellent yield of the expected substitution product. Brief exposure of this product to ethanolic potassium hydroxide solution resulted in smooth, high yield substitution of the remaining chlorine atom. Monobromination of this latter product with... 

Isatins fail to yield Knoevenagel condensation products with malonic acid419. However, malonic acid can be condensed with isatin in a mixture of ethanol and pyridine, in which the initial condensation product suffers decarboxylation, furnishing an acetic acid derivative. This can be converted to the acid chloride and submitted to a Friedel-Crafts acylation reaction, yielding acetophenone derivatives420. Alternatively the oxoindolinylidene acetic acid derivative can be treated with an arene in the presence of AICI3 to yield. sy />o[indoline-3,3 -indan]-2,l-dione derivatives. ... 

The reactive 1 1 intermediate formed in the initial reaction between trialkyl phosphite and dialkyl acetylenedicarboxylates can be trapped. Thns, reaction of dialkyl acetylenedicarboxylates with trimethyl phosphite in the presence of indane-1,3-dione leads to dimethyl 2-(3-methoxy-l-oxoindenyl)-l,2-fczXalkoxycarbonyl)ethylphosphonate in high yields. Treatment of trialkyl phosphites with Cgo and dimethyl acetylenedicarboxylate at 80°C give fullerenecyclopropyl phosphite ylides, which, on hydrolysis at ambient temperature, give the corresponding phosphonates. ... 

After an early report in the 1960 s on some reactions of alkynylphenyliodonium salts,the chemistry of these species laid dormant until the mid 1980 s. Since then, this field has experienced an intense development. In 1965, Beringer and Galton reported the alkynylation of 2-substituted indane-1,3-dione in good yield, by reaction of the sodium salt of indanedione with phenyl(phenylalkynyl) iodonium chloride (80). 77... 

Condensation of primary dimedone enaminones with formaldehyde according to Greenhill and coworkers " give, in neutral medium, methylenbisenaminones, whereas acidic conditions produce spirocompounds. Structure A is given by Greenhill for the spiro-product, but structure B (equation 20) also seems reasonable. Modem spectroscopic methods should be used to solve this problem. Similar products are obtained in the Mannich reaction of enaminones derived from indan-l,3-dione . 

Hydrogenation of Knoevenagel products of 2,4-alkanediones over Raney nickel provides a simple route to 3-substituted 2.4-diones. Alternatively, reductive deacetylation can be accomplished using tetracarbonylhydridoferrate(0) in ethanol to prepare alkyl ketones. If the reaction is carried out in THF or acetone, exclusive reduction of the a,p-unsaturated double bond is observed. - Reactions of aldehydes with cyclic 1,3-diketones generally lead to the formation of Michael adducts under standard conditions. Indane-l,3-dione (103) yields Knoevenagel products with different aldehydes, ketones and ketimines, whereas perinaphthindane-l,3-dione (KM) gives the Michael adducts. ... 

The reactivity of pyridazine-3- and 4-carbaldehydes towards active methylene reagents under the conditions of Knoevenagel, Wittig, and Hantzsch-type reactions has been examined. The 4-aldehyde reacts readily with malononitrile and methyl cyanoacetate, and less readily with triethyl phos-phonoacetate, indane-l,3-dione and alkyl acetoacetates/ammonia (e.g.. Scheme 52). Condensation with nitroethane is successful, but nitromethane gives an unstable intermediate which decomposes. The 3-aldehyde has similar reactivity to the 4-aldehyde, but some reactions are unsuccessful due to reduced reactivity, or instability of the products <90JHC1313>. 

The reaction of tosyl azide with indane-l,3-dione (143, R = H), carried out in HMPA or in diethyl ether in the presence of NEt3, fails to afford the expected diazo transfer indan-l,3-dione.67 However, the 2-phenylsulfanylindan-l,3-dione (151) in the presence ofNEt3 gives diazo diketone (152) in 36% yield.49,67... 

A novel electrophile substitution, based on the reaction of ninhydrin in refluxing acetic acid over 2 hours with 2-methylphenol, afford 2-hydroxy-2-(2-hydroxy-3-methylphenyl)indane-1,3-dione in 78% yield. With 4-methylaniline in refluxing acetic acid for 12 hours, 3- 2-hydroxy-3-methyl-... 

Additional modifications to the Hantzsch 1,4-dihydropyridine synthesis generally involve the use of activated methylene compounds such as 1,3-diketones, co-cyanoacetophenone, co-phenylacetophenone, a, P-unsaturated ketones, and indane-l,3-diones. A number of efforts to improve reaction yields using eatalysts have also been reported, including the use of hydrotalcite materials, triphenylphosphine copper II triflate, and covalently anchored sulfonic acid on silica gel. Dihydropyridine synthesis has also recently been studied with high success using microwave and solvent-free" reaction conditions. 

Non-aqueous Solvent Mixtures.— The kinetic pattern for reaction between nickel(ii) and murexide in mixtures consisting of the co-ordinating solvent DMSO and the non-co-ordinating solvent nitromethane fit an la but not a D mechanism. Rate-limiting ring closure is not expected in this system, but may be a complicating factor in the reactions of nickel(n) with 4-(2-pyridylazo)resorcinol and with 2,2 -nitrilodi-indane-l,3-dione in pyridine-nitromethane mixtures. Trends and extrema in the kinetic parameters for reaction of copper(ii) with chlorophyllic acid in pentanol-acetic acid and in methanol-acetic acid mixtures are explained in terms of solvent structural properties. ... 

Photoinduced reactions of cyclic a-diketones with different alkenes takes place via [2 + 2], [4 + 2] or [4 + 4] photocycloaddition pathways. Photoaddition of electron deficient silyl ketene acetals to 2-, 3- and 4-acetylpyridine generates oxetanes as major products. The reaction is favoured in non polar solvents. The photoreaction between silyl enol ethers and henzil affords [2 + 2] cycloaddition products, while in the case of 9,10-phenanthrenequinone [4 + 2] cycloacidition predominates. Photocycloaddition of p-henzoquinones to hicyclopropylidene affords spirooxetanes (21) as the primacy products further irradiation leads to rearranged spiro[4.5]deca-6,9-diene-2,8-diones. With 9,10-anthraqui-none, in addition to the spirooxetane, a spiro[indan-l,l -phthalan]-3 -one is also obtained. ... 

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