5-Chloroanthranilic acid

As a structure proof, the compound was prepared by an alternate route 5-chloroanthranilic acid, prepared by the chlorination of anthranilic acid, according to J. Am. Chem.Soc. 68, 1303 (1946) was converted into 5-chloro-2-mercaptobenzoic acid by the method described in J. Org. Chem., 18, 1380 (1953), and the latter was condensed with benzene by means of sulfuric acid to yield 10-(2-chloro)thiaxanthenone, identical with that obtained by the first method. 

Some isatoic acid anhydrides are readily hydrolyzed during oxidation so that the corresponding A -(2-hydroxyphenyl)oxamidic acids are isolated as products [260], With 7-chloroisatin, treatment with 30% hydrogen peroxide in 5% aqueous sodium hydroxide for 40 min at 65 °C produces chloroanthranilic acid in 78% yield (equation 395) [1168]. 

Ca. 1M ethyl-MgBr added at 8 during 22 min. to a stirred suspension of N-(4-methoxyphenyl)-4-chloroanthranilic acid in dry ether, warmed to 45°, stirred for an additional 40 min., cooled in ice, treated with a soln. of acetic anhydride in dry ether, refluxed 80 min., then mechanically shaken for 12 hrs. - N-acetyl-N-(4-methoxyphenyl)-4-chloroanthranilic acid. Y 53-60%. (L. J. Sargent, J. Org. Chem. 14, 285 (1949).)... 

Pyrrolnitrin.—Pyrrolnitrin (109) is a metabolite of Pseudomonas aureofaciens and is derived from tryptophan. The amino-compound (108) is naturally occurring, and (107) has now also been isolated." This, taken together with evidence from feeding experiments (cf. ref. 4, p. 28), indicates the pathway shown in Scheme 4.3-Chloroanthranilic acid and 7-chloroindoleacetic acid have also been isolated from P. aureofaciens ... 

To a solution of NaOEt prepared from 0.11 g sodium (4.7 mmol) and 10 mL absolute ethanol, cooled in an ice bath, was added in rapid succession 0.88 g methyl 2-chloro-6-hydroxybenzoate (4.7 mmol) and a solution of 1.14 g A-4-methoxyphenylbenzimidyl chloride (4.7 mmol) in 30 mL dry ether. The reaction mixture was shaken vigorously, whereupon a precipitate of sodium chloride began to form. The mixture was allowed to stand at room temperature for 48 h, the solvent was evaporated, and the residue was diluted with water. The resulting oily solid was removed by extraction with ether, the ethereal solution was dried, and the ether was distilled. The crude imido ester was heated in a nitrogen atmosphere at 210-215 C for 70 min, then dissolved in 10.8 mL ethanol the alcoholic solution was diluted with 5.4 mL water and 5.4 mL of a 1 M ethanolic sodium ethoxide. The solution was refluxed for 1.5 h, the alcohol was evaporated on a steam bath, and the aqueous solution was acidified with dilute HCl. The dark oil that formed was separated by decantation, and the crude benzoate of the substituted anthranilic acid was dissolved in 22 mL ethanol. A solution of 7.2 g sodium hydroxide in 7.2 mL water was added, and the mixture was refluxed for 1 h. The alcohol was evaporated, and the solution was then acidified. The brown solid was extracted exhaustively with boiling water to remove the benzoic acid, and the remaining brown solid was recrystallized from aqueous ethanol. The yellow needle-like crystals of A-(4 -methoxyphenyl)-6-chloroanthranilic acid, in a total amount of 0.36 g, was obtained, in a yield of 27.7%, m.p., 139.5-140.5°C (dec). 

Benzene ring synthesis 6-Chloroanthranilic acid esters... 

The products obtained from esters of anthranilic acid and substituted anthranilic acids are of interest because fluorenones can be prepared from them. From diazotized methyl anthranilate and benzene, 2-carbometh-oxybiphenyl is obtained in 24% yield. Hydrolysis affords 2-biphenylcar-boxylic acid, which can be cyclized to fluorenone. By this procedure, a number of 2- and 3-substituted fluorenones have been prepared.16 Thus, 3-chlorofluorenone was prepared from methyl 4-chloroanthranilate and benzene through the following steps. 

Arya et al. prepared the pyrrolo[l,2-a]quinazoline 94 directly from anthranilamide and butyrolactone, in a yield of 45%, by reaction in acetic acid in the presence of boron trifluoride etherate. The 7-chloro and 8-chloro derivatives of 94 were prepared similarly. The 8-chloro derivative of 94 was also synthesized from methyl 4-chloroanthranilate and y-chlorobutyroni-trile. ... 

Potassium cyanate and methyl 3-methoxyanthranilate, left in cold, acidified aqueous solution overnight, deposited methyl 2-ureido-3-methoxy-benzoate, which, when boiled with water, cyclized to 8-methoxyquinazo-line-2,4-dione methyl 5-chloroanthranilate behaved similarly (no yields stated).257 2-Amino-3-ethoxycarbonyl-JV-methylpyridinium iodide, refluxed for 24 hr with potassium cyanate in dilute acetic acid, was converted in good yield to 8-methylpyrido[2,3-rf]pyrimidine (183).344... 

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