Homophthalate

Homophthalic acid. This is a four-stage preparation with phthalic anhydride as the starting material ... 

Homophthalic acid. Place a mixture of 25 g. of o-carboxyphenylacetonitrile and 25 g. of 50 per cent, sulphuric acid in a 100 ml. flask, heat... 

Homofolic acid, 5,11-methenyl-tetrahydro-biological activity, 3, 327 Homofolic acid, tetrahydro-biological activity, 3, 327 Homoisoflavanones occurrence, 3, 722 thermoisomerization, 3, 722 thermolysis, 3, 728 Homolytic reactions heterocyclic compounds reviews, 1, 74 Homophthalic acid isocoumarins synthesis from, 3, 830 synthesis, 3, 830 Homophthalic anhydride isochroman-l-one synthesis from, 3, 860 20a-Homoporphyrin nomenclature, 1, 30 Homopterocarpin isolation, 4, 998 ( )- D- Homotestosterone synthesis, 1, 453 Homer-Emmons reaction chromene synthesis by, 3, 749 Hortiacine isolation, 3, 149 Hortiamine isolation, 3, 149... 

The first direct approach to a pentacyclic system, based on the condensation product 101 of tryptamine with a homophthalic acid or anhydride, was introduced by Clemo and Swan and extended to reduced and substituted homophthalates. Esterification of... 

Homophthalic anhydride (5.0 g, 31 mmol) was added to a solution of 85% hydrazine hydrate (1.8 mL, 31 mmol) in EtOH (40 mL) and the mixture was heated under reflux for 6 h. The resulting precipitate was filtered off and washed with HOAc the product crystallized (EtOH) as colorless flakes yield 4.3 g (65 %) mp 298-300 JC. 

In a facile and rapid stereoselective, three-component, one-pot reaction, a series of cis-isoquinolonic acids 132 were synthesized using silica supported sulfuric acid to catalyze the reaction between homophthalic anhydride 133 with different aldehydes 134 and amines 135. This three-component cyclocondensation offers a variety of advantages including high yields, easy experimental work-up, and the use an inexpensive, non-toxic, readily available, and recyclable catalyst <06JHC187>. 

Ten grams (0.056 mole) of 2u-thiohomophthalimide 2-and a solution of 30 g. of potassium hydroxide in 125 ml. of water are placed in a 300-ml., one-necked, round-bottomed flask (Note 1). The mixture is refluxed for 48 hours, filtered, and acidified with 122V hydrochloric acid. The solid that forms on cooling is collected by filtration and recrystallized from a mixture of 25 ml. of water and as much acetic acid (about 7 ml.) as necessary to dissolve the solid in the boiling solution, with addition of a little activated carbon. The yield of homophthalic acid, m.p. 181° (Note 2), is 6.1-7.5 g. (60-73%) (Note 3). 

Homophthalic acid may be obtained by the oxidation of in-dene,3-4 the reduction of phthalonic acid,6-6 and the hydrolysis of o-carboxyphenylacetonitrile.7 Other methods are listed in an earlier volume.3... 

This is a general method for converting 2a-thiohomophthaIim-ides to homophthalic acids. Since 2a-thiohomophthalimides are readily obtained from phenylacetyl chlorides,2 this is a convenient method for preparing homophthalic acids. 

The thioimides can be hydrolyzed to the corresponding di-carboxylic acids. The thioimides can be converted to the corresponding imides, and thiohomophthalimides can be converted to phthalimides both conversions are one-step processes.4 Thus a variety of substituted phthalic and homophthalic acids and their derivatives are available from these thioimides. 

Allene-l,3-dicarboxylates no are also useful dienophiles for [4+ 2]-cycloadditions. They react with 1,3-dienes to give 4-methylenecyclohexene derivatives 111. The aro-matization shown produced homophthalic derivatives 112 and 113 [96]. 

The observed ambient organic aerosol formation rates are also consistent with those estimated by extrapolation of smog-chamber kinetic data. Other heavy unsaturates, such as styrene and indene, are present in the atmosphere and may contribute, in part, to the formation of benzoic acid and homophthalic acid, respectively. Diesel exhaust and industrial emission are possible sources of such heavy unsaturates. Diolefins of C6+ are not present in gasolines and exhaust gases and have not been found in the atmosphere, and their possible role as precursors of the Cs-7 difiinctional acidic compounds is seriously challenged. Lower diolefins are emitted in automobile exhaust. Examination of vapor-pressure data indicates that the bulk of their expected photooxidation products remains in the gas phase, including most of the less volatile C3-4 dicarboxylic acids. 

The achiral ionic liquid [bmim][BF ] was able to catalyze the three component reaction of benzaldehyde, aniline and homophthalic anhydride in 90% yield. Next to the major ciT-isomer, 10% tran.f-isomer was isolated after 3 h (Scheme 74) [196]. Control reactions in CH Cl with 10 mol% [bmim][BF ] and without catalyst showed that in the presence of the ionic hquid a high conversion in a short time was observed. Application of polar solvents like methanol or acetonitrile made it necessary to increase the reaction temperature to 70-80 °C, and the product was obtained in only 45-60% yield in a prolonged reaction time of 8-15 h. Further control reactions with [nBu NllCl] or [bmim] [Cl] showed that the anion played a comparable important role as the cation, since no product was formed. The author could demonstrate the generality of the reaction by the application of a broad variety of benzaldehyde and anihne derivatives. 

The ionic liquid [BMIM]BF4 was found to efficiently catalyze the three-component coupling reactions of aldehydes, amines, and homophthalic anhydride under ambient conditions to give the corresponding c/ -isoquinolonic acids in excellent yields with... 

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