1520 HAYASHI A NEW ISOMERISM OF CXCII1.-A New Isomerism of Halogenohydroxybenzoyl-toluic Acids. Part III. 2-(3'-Chloro-4'-hydroxy-benxoyl)-3(or 6)-methylbenzoic Acid. By MOSUKEHAYASHI. THEauthor has reported in preceding papers (J.,1927 2516; this vol. p. 1513) that the action of concentrated sulphuric acid on halogenohydroxybenzoyltoluic acids which have the halogen in the pposition to the hydroxyl group gave rise to an isomeric change. He now submits the results of analogous studies with halogeno- hydroxybenzoyltoluic aoids which have the halogen in the o-position to the hydroxyl group. When 3-methylphthalic anhydride was condensed with o-chloro- phenol or with o-chloroanisole in the presence of anhydrous alumin- ium chloride only one chlorohydroxybenzoyltoluicacid (A),m.p. 198-199" (anhydrous) was obtained. On treatment of this pcid with concentrated sulphuric acid at room temperature an isomeric change occurred and chlorohydroxybenzoyltoluic acid (A'),m. p. 188.5-189" was obtained. The (A) acid may have any of the formulae (I) (11) (111) and (IV),in harmony with the rule which has been already mentioned in a previous paper (Part I Zoc. cit.). Me Me However when phthdic anhydride was condensed with o-chloro- phenol or with o-chloroanisole in the presence of anhydrous alumin- ium chloride 2-(3'-cRZoro-4'-hydroz~~e~~o~Z)~e~zoic acid only was obtained and 2-(3'-chloro-2'-hydroxybenzoyl)benzoicacid could not be isolated. The constitutional formula of the (A) acid may there- fore be either (11) or (IV).The isomeric change should be the transformation of (11)into (IV) or vice versa since it is improbable that the carboxytoluoyl group would migrate into the o-position to the hydroxyl group. This view receives important support from the great similarity of the ultra-violet absorption curves of the acids (A) and (A') and of the 2-(3'-chloro-4'-hydroxybenzoyl)-benzoic acid. HALOGENOHYDROXPBENZOYLTOLUIC ACIDS. PART III. 1521 A definite allocation of formuh to the acids (A) and (A') is not feasible but taking cognisance of the known influence of the methyl group in analogous reactions it is highly probable that 2-(3'-chloro- 4'-hydroxybenzoyl)-3-methylbenzoicacid (11) would be produced more easily than 2-(3'-chloro-4'-hydroxybenzoyl)-6-methylbenzoic acid (IV) when 3-methylphthalic anhydride is condensed with o-chlorophenol.Therefore it seems probable that the chloro-hydroxybenzoyltoluic acid (A) is 2-(3'-chZoro-4'-hydroxybenxoyZ) -3-rnethylbenxoic acid (11) and the chlorohydroxybenzopltoluic acid (A') is 2- (3'-chEoro-4'-hydroxybenxoyZ) -6-methylbenxoic acid (IV). When phthalic anhydride was condensed with o-chlorophenol or with o-chloroanisole in acetylene tetrachloride solution in the presence of aluminium chloride a chlorohydroxybenzoylbenzoic acid m. p. 219.5-220" was obtained (V or VI). When the chlorohydroxybenzoylbenzoic acid m. p. 219-5-220" was heated at 195" with a solution of boric acid in concentrated sulphuric acid 2 -chloro-3 -hydroxyanthraquinone (VIII) was ob-tained (compare Tanaka Proc.Imp. Acard. Tokyo 1927 3,82; or Bull. Agr. Chern. SOC.Japan 1927 3,17). Therefore the chloro- hydroxybenzoylbenzoic acid m. p. 219.5-220" is probably 2-(3'- chloro-4'-hydroxybenzoyl)benzoicacid (VI). EXPERIMENTAL. Condensation of 3-Methylphthdic Anhydride with o-Chlorophenol or with o-Chloroanisole. 2- (3'-Chloro-4'-hydroxybenxo yl)-3(or 6) methyl- benxoic Acid (A).-Powdered aluminium chloride (25 9.) was gradu- ally added with frequent shaking to a solution of 3-methylphthalic anhydride (10 g.) and o-chlorophenol (9 g.) in acetylene tetrachloride (50 c.c.). The mixture was then heated at 125-135" (oil-bath) and the product was mixed with ice-water and an excess of hydro- chloric acid and distilled in steam.An ammoniacal extract of the residue was Concentrated and then again diluted with water; the greyish-brown precipitate (4g.) that separated was removed [m. p. 110-140" (decomp.); unidentified] and the filtrate on acidification afforded the crude acid (15 g.) m. p. 194-197" in 83.6% yield. 3~2 1522 HAYASHI A NEW ISOMEBCISM OF After several recrystallisafions from acetic acid colourless micro- scopic needles were obtained (Found in air-dried material loss at 105" in a vacuum 5.9. Cl,H1,O,Cl,H,O requires H,O 5-Sy0. Found in anhydrous material C 61.9; H,4.0; C1 12.15. C1,Hl1O,C1 requires C,61.95; H,3.8 ; C1 12-20/). The anhydrous acid melts at 198-199". It is easily soluble in alcohol and hot acetic acid but very sparingly soluble in benzene or light petroleum.The solution in concentrated sulphuric acid is at &st yellow but gradually develops a red colour. The ultra-violet absorption curve of an alcoholic solution of this acid shows a band with head at A 2840 8. 2-(3'-ChEoro-4'-fiydroxybenzoyl)-6(or3)-methyZbenxoic Acid (A').-After a solution of 2-(3'-chloro-4'-hydroxybenzoyl)-3(or6)-methyl-benzoic acid (A) (1 g.) in 98% sulphuric acid (6 c.c.) had been kept for one day at room temperature the isolated product dissolved completely in aqueous sodium carbonate and on acidification of the solution an almost colourless substance was precipitated (0.95 g.) m. p. 187-189". On crystallisation from acetic acid colourless microscopic needles m. p. 188.5-189" were obtained (Found C 62.1; H 4.1; C1 12-25.C1,H1,O,C1 requires C 61.95; H,3-8; C1 12.2%). This acid closely resembles t,he isomeride (A) and the ultra-violet absorption curve of its alcoholic solution shows 8 band with head at A 2850 A. When the acid (A)(1 g.) was heated with concentratted sulphuric acid (98% 6 c.c.) at 120-130" for 1 hour crude acid (A')(0.9g.) m. p. 186-188" was obtained. And also when a solution of the acid (A) in concentrated sulphuric acid was heated at 140" or 150-160" for 1 hour crude acid (A') only was obtained; no anthra- quinone derivative could be isolated. 3-Methylphthalic anhydride (5 g.) was condensed with o-chloro- anisole (5g.) (acetylene tetrachloride 25 C.C.; anhydrous aluminium chloride 12.5 g.) under the same conditions as in the case of o-chloro-phenol.In this case crude 2-(3'-chloro-4'-hydroxybe~~zoyl)-3jor 6)- methylbenzoic acid (A)(7.2g. ; 80.5y0),m. p. 194-196" (anhydrous) wits obtained and no other substance was isolated. 2-(3'-ChZoro-4'-hydroxybenxoyl)henxoic Acid.-Pht halic anhydride (5 9.) and o-chlorophenol (5 g.) were dissolved in acetylene tetra- chloride (25 c.c.) powdered aluminium chloride (12.5 g.) was gradually added with shaking and the mixture heated slowly. After 2 hours' heat>ing at 120-130" the product was cooled mixed with ice-water and after the addition of an excess of hydrochloric acid distilled in steam. The residue was extracted with ether the extract washed with sodium carbonate solution and the acid HALOGENOHYDROXYBENZOYLTOLUICACIDS.PART m. 1523 regenerated (m. p. 219-220"; 9 g. 96.3%); it separated from glacial acetic acid in colourless crystals m. p. 219-5-220" (Found C,60.7; H,3.5; C1 12.8. C,,H,OpCl requires C 60.75; H 3.3; C1 12.8%). This acid exhibited the usual properties of its class and showed an absorption band with a head at A 2840 A. (solvent alcohol). When a solution of this acid in concentrated sulphuric acid (98-25y0 6 vols.) was kept over-night at room temperature the whole of the substance could be recovered unchanged. Aluminium chloride (12-5 g.) was gradually added to a solution of phthalic anhydride (5 g.) and o-chloroanisole (5 g.) in acetylene tetrachloride (25 c.c.) and the subsequent treatment and the separation of the reaction product were carried out as in the case of o-chlorophenol.Crude 2-(3'-chloro-4'-hydroxybenzoyl)benzoic acid m. p. 212-216" only was obtained in 97% yield (9.1 g.). 2-(3'-Chbro-4'-methoxybenxoyb)benxoic Acid .-2 -(3'-Chlor0-4' -h y dr -oxybenzoy1)benzoic acid (3 g.) was converted into its potassium salt which was thoroughly dried and suspended in toluene (50 c.c.) methyl sulphate (6 g.) introduced and the mixture gradually heated. After 2 hours' boiling the product was mixed with 25% potassium hydroxide solution (20 c.c.) and dist'illed in steam. The residue was an almost colourless substance (3 g. 9550/) m. p. 160-166" which crystallised from acetic acid in microscopic pillars m. p. 179-180" (Found C 62-25; H 4.1; C1 12-2. C,,H,,O,Cl requires C 61.95; H 3-8; C1 12.2%).The solubility and other properties were normal and the alcoholic solution exhibited an absorption band with a head at A 2810 a. 2-Chloro-3-hydroxyanthraquinone.-The anthraquinone derivative was not obtained when 2-(3'-chloro-4'-hydroxybenzoyl)benzoic acid was heated even with lOOyosulphuric acid at 195" for 1.5hours. 2-(3'-Chloro-4'-hydroxybenzoyl) benzoic acid (1 g.) was heated with a solution of boric acid (1.59.) in 100% sulphuric acid (16c.c.) at 195" for 1.5 hours and the product poured into ice-water. The yellow precipitate was washed with boiling water and crystallised from alcohol (0.5 g.; 53.5%). The substance was purified by solution in and recovery from aqueous sodium carbonate and crystallised from acetic acid in yellow feathery needles m. p. 266.5-267" (Tanaka Zoc. cit. gives m. p. 258') (Found C 65.0 ; H 2.9; C1 13.7. Calc. for C,,H,O,Cl C 65-0; H 2-7; C1 13.7:/,). This chlorohydroxyanthraquinone exhibits two absorption bands with heads at A 3120 and 2730 A. (solvent alcohol). TOHOKU UNIVERSITY, IMPERIAL SENDAI,JAPAN. [Received August 27th 1929.1