Phthalaldehyde acid

Submitted by J. H. Gardner and C. A. Naylor, Ir. Checked by C. R. Noller and Carl Limn. 

The filtrate is acidified with 150 cc. (r.8 moles) of concentrated hydrochloric add (sp. gr. 1.18), evaporated to 500 cc., cooled, and filtered. The filtrate is neutralized with 30 per cent sodium hydroxide solution (150-160 cc.), 50 g. (0.48 mole) of sodium bisulfite is added, and the mixture is evaporated to dryness on a steam bath. The residue is stirred with 100 cc. of concentrated hydrochloric acid and evaporated to dryness on a steam bath. The hydrochloric acid treatment and evaporation are repeated (Note 2). 

The residue is extracted thoroughly with benzene in a large Soxhlet extractor (Note 3), and the benzene extract is evaporated to dryness. The crude product is dissolved in 50 cc. of hot water, the solution filtered, and the filtrate cooled in an ice bath with stirring (Note 4). The crystals are filtered with suction and dried in the air. The yield of slightly colored product melting at 94-95° is 15-15.5 g- (40 41 per cent of the theoretical amount). 

When this material is recrystallized from 40 cc. of water with 1 g. of decolorizing carbon, and the filtrate cooled to o°, there is obtained 14-14.5 g. of white crystals melting at 96-96.5°. 

During the addition of the hot permanganate solution no external heat is applied. From time to time steam is passed through the condenser jacket to return the sublimed naphthalene to the reaction flask. 

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Dich1oromethy1)-2-(trichioromethy1)henzene [2741-57-3] the end product of exhaustive side-chain chlorination of o-xylene (80) is an iatermediate ia the manufacture of phthalaldehydic acid [119-67-5]. 

In a similar manner, phthalazine or its alkyl- or aryl-substituted derivatives are obtainable from 1,2-diacylarenes (Scheme 76). Phthalaldehydic acid and its analogs are transformed by hydrazines into the corresponding phthalazin-l(2//)-ones. Phthalazin-l(2iT)-one itself is prepared from naphthalene by oxidation, subsequent treatment with hydrazine and decarboxylation as shown in Scheme 77 (55YZ1423,64FRP1335759). 4-Substituted phthalazin-l(2iT)-ones are prepared in a similar way from 2-acylbenzoic acids. 3-Hydroxyphthalides,... 

Phthalaldehydic acid (o-formylbenzoic acid) gives the NMR spectra set 32. In what form does the compound actually exist ... 

Phthalaldehyde Acid (16, 68) By chlorination of phthalide, followe by hydrolysis with boiling water and crystallization from benzene. Austin and Bousquet, U. S. pat. 2,047,946 [C. A. 30,6on (rg36)]. 

B) Phthalaldehydic Acid.—The entire distillate is placed in a 500-cc. flask and covered with 230 cc. of water. The flask is equipped with a mechanical stirrer and is heated on a steam cone. The hydrolysis is complete when the layer of 2-bromophthalide has disappeared (about thirty minutes). The reaction mixture is then placed in a refrigerator overnight, during which time the entire mass solidifies. The product is filtered, washed with two 50-cc. portions of ice water, and dried in the air. The yield of crude product melting at 60-65° (Note 5) is 140-160 g. 

Phenyl thiocarbamide, pi58 a-Phenyl-o-tohiic acid, b84 Phenyl m-tolyl ether, p76 Phloroglucinol, t318 Phorone, d613 Phthalaldehydic acid, 37... 

A variety of cyclic products have been prepared from educts containing carbonyl as well as carboxylic groups. Thus, Hanusch-Kompa and Ugi prepared a large number of five-membered cyclic gamma-lactam compounds like 44 from levulinic acid. Other carbonylic acids can lead to compounds like 45, which is made from phthalaldehyde acid, valine methylester, and tert-butylisocyanide. The products like 46 and 47 can result from the U-4CR and further cyclization. 

Diphenylbenzo[( ]furan has been observed in a number of other reactions. When benzocyclobutadienequinone (172), monothiophthalic anhydride (173), chlorophthalide (the chloride of o-phthalaldehydic acid, 174),and 2-cyanobenzaldehyde (175) are treated with phenylmagne-sium bromide, 138 could be obtained. This last reaction, which yields an imine in the primary stage, has also been conducted with p-methoxy-phenylmagnesium bromide. ... 

Dihydroisoindolo[2,l-a]quinazoline (e.g. 82) was claimed (54JCS2354 80AP729) to be the product of the reaction between 2-aminobenzylamine and phthalaldehyde (80AP729) or phthalaldehydic acid (54JCS2354). The... 

The 13C NMR spectrum of phthalic dichloride shows additional signals for a five-membered cyclic pseudo halide, characterized by an sp3 carbon shift of 104 ppm. This shift value is also observed for laevulic acid chloride, which exists in the cyclic form only. Similarly, phthalaldehyde acid (o-formylbenzoic acid) turns out to be hydroxyphthalide, as indicated by a hemiacetal carbon shift of 98.4 ppm. 

Phthalaldehydic acid - [CHLOROCARBONS ANDCHLOROHYDROCARBONS - BENZYL CHLORIDE, BENZAL CHLORIDE AND BENZOTRICHLORIDE] (Vol 6)... 

Phloroglucinol, t305 Phorone, d529 Phthalaldehydic acid, f33 m-Phthalic acid, bl6 p-Phthalic acid, bl7 Phthalonitrile, d236... 

Crounse and Desai29 showed further that 2-(/>-tolyl)benzo[6]furan with Schiff s base derived from terephthalaldehydic acid and aniline gives, on treatment with excess potassium r-butoxide, the corresponding stilbene carboxylic acid. Schiff s base derived from phthalaldehydic acid and aniline exists30 as the 3-anilinophthalide (40). Nevertheless, this also reacts similarly with, for example, the naphthofuran (39) to form 2-(2 -carboxystilben-4-yl)naphtho [ 1,2-6]furan (41).29 Analogous car-... 

During the synthesis of the isocoumarin moiety of heliquinomycin, diethyl bromomalonate and phthalaldehydic acid 1137 condense to form the dihydroisocoumarin 1138 in excellent yield (Equation 442) <2000TL29>. 

Photoflood lamps, 20, 84, 104 Phthalaldehydic acid, 23, 74 Phthalic acid, 24, 45 Phthalic anhydride, 20, 70 27, 78 Phthalic anhydride, tetraiodo-, 27, 78... 

On treatment with acids or bases, both the monomethoxy and the dimethoxy six-membered ring peroxide are converted into the methyl ester of o-phthalaldehydic acid or into o-phthalaldehydic acid, depending on the reaction conditions. Oxidation with hydrogen peroxide yields o-phthalic acid.87 The hydrogenation of 135 in the presence of a Lindlar catalyst leads to o-phthaldialdehyde (yield =... 

This strategy has been used to convert o-bn mobcnzaldehydes into phthalaldehydic acids (equation I). 

Finally, four different examples of solvent-dependent ringichain tautomerism should be mentioned [77, 210]. The equilibrium between phthalaldehydic acid / 18a) and phthalide (18b), which in decalin lies in favor of (18b) (90 cmol/mol phthalide at 20 °C), is strongly shifted towards the open-chain form (18a) in the hydrogen-bond accepting solvent dimethyl sulfoxide (only 5 cmol/mol phthalide) [78]. 

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