Dichlor-a-naphthol, CH,Cl2 OH [OH: Cl2 = 1: 2: 4], is the first product which can be isolated of the action of chlorine on a-naphthol in glacial acetic acid solution; it is also formed by the reduction of tri- and penta-chloroketonaphthalene (see below). It crystallises from glacial acetic acid in thick, transparent needles, which lose acetic acid, become dull, and disintegrate on exposure to the air; it crystallises from benzene and alcohol in slender, shining needles, which melt at 107-108°, dissolve readily in ether, benzene, and absolute alcohol, and also in sodium carbonate with evolution of carbonic anhydride. It is readily oxidised by chlorine or bromine with formation of an insoluble, blue substance, which, on further treatment with the halogen, becomes yellow. This blue compound is also formed by the action of trichloro ketonaphthalene. By careful oxidation with nitric acid, dichlor-z-naphthol yields chlor-a-naphthaquinone. The acetylderivative, CH,Cl2OAc, is readily soluble in glacial acetic acid and alcohol, and crystallises from the latter in thick, colourless needles, melting at 74—76°.

Trichlor-a-naphthol, [Cl, 2:3: 4], is obtained by reducing pentachloroketonaphthalene with alkaline sulphites; it crystallises from glacial acetic acid or benzene in long, colourless, silky needles, melts at 159-160°, is readily soluble in ether, less readily in warm, sparingly in cold alcohol or glacial acetic acid. The acetylderivative forms long, white, shining needles, which are moderately soluble, and melt at 123-124°. Trichlora-naphthol yields dichloro-ẞ-naphthaquinone, and a small quantity of dichlor-a-naphthaquinone, when carefully oxidised with nitric acid in acetic acid solution, but with chromic acid the chief product is dichlor-a-naphthaquinone.

CCICH

Trichlor-a-ketonaphthalene, C.H.<COCC> or C.H.CO, CH (chlor-a-naphthaquinone chloride), is the second product of the action of chlorine on a-naphthol in glacial acetic acid solution; it crystallises in large, characteristic, transparent, flat, monoclinic prisms, melting at 120-121°, is very readily soluble in benzene, less so in glacial acetic acid, and sparingly in alcohol. This compound can also be obtained by the action of chlorine on dichlor-a-naphthol. When boiled with dilute alcohol or dilute acetic acid, it yields chlor-anaphthaquinone, C.H.CO.CC This crystallises from alcohol and dilute acetic acid in shining, yellow needles, which melt at 117–118°, and are readily soluble in benzene, sparingly in ether. When treated with chlorine in glacial acetic acid solution, it is converted into dichlor-a-naphthaquinone, and alkalis transform it slowly, with partial decomposition, into chlorohydroxynaphthaquinone. Treated with aniline, it yields chloranilido-a-naphthaquinone, which can also be obtained from dichloronaphthaquinone.

Trichloroketonaphthalene can be readily reduced to dichlor-anaphthol, and when treated with aniline it yields anilidonaphthaquinonanilide. By the action of hydroxylamine hydrochloride on trichloroketonaphthalene, three different nitrogenous products are formed, two of which are insoluble in sodium carbonate; one of these

is probably a true nitroso-compound, CH,Cl2 NO [NO: Cl2 = 1:2:4]. The product which is soluble in sodium carbonate appears to be a monoxime; it melts at 146-149°, and decomposes at 170°. The third product is sparingly soluble, and melts at 205°.

Tetrachlor-a-ketonaphthalene, C«H<

-CO.CCI2

(or dichlor-a-naph

thaquinone chloride, C.HCC, CCI), was obtained in two different modifications, which perhaps have different constitutions as expressed by the above formula. Both compounds are formed by treating trichlor-a-naphthol with chlorine. The a-modification crystallises from glacial acetic acid in small, transparent rhombohedra, which, when taken from the solution, become yellow, and keep their colour when recrystallised from ether; it is rather easily soluble in hot alcohol or hot glacial acetic acid, and melts at 104-105°.

The B-modification crystallises from ether in shining, colourless, transparent, rhombic forms, which are combinations of prisms and pyramids; it melts at 93-94°, and becomes amethyst-coloured on exposure to light.

The B-modification can also be obtained by treating an alcoholic solution of the pentachloride (see below) with dilute alkali, or by boiling an alcoholic solution of the a-modification; in the latter case, dichlor-a-naphthaquinone is also formed.

These two modifications of tetrachlor-a-ketonapthalene are very similar in their general behaviour; they are both converted into dichlor-a-naphthaquinone when boiled with dilute alcohol or dilute acetic acid; when warmed with dilute alcoholic potash, they yield chlorhydroxynaphthaquinone, and when treated with concentrated potash and a few drops of alcohol, they are converted into dichlorindenehydroxycarboxylic acid, which can be recognised by transforming it into dichloroketoindene, C.H.CCCCI.

CO

When potash is gradually added to a solution of the tetrachloride in absolute alcohol, long, orange-red shining needles, melting at 148-149°, are obtained. This compound, which can also be obtained from the pentachloride, appears to be the ethyl-derivative CO― CO.

of chlorhydroxynaphthaquinone, C.HC(OEt):CCI; it yields B-B-chlorhydroxy-B-naphthaquinone anilide when treated with aniline, and is converted into chlorhydroxynaphthaquinone by the action of alkalis.

The corresponding propyl-derivative is obtained by treating a propyl-alcoholic solution of the tetrachloride with potash in a similar manner; it is a yellowish-red, crystalline compound, which melts at 190°, and gives B-B-chlorhydroxynaphthaquinoneanilide when treated with aniline.

Tetrachloroketonaphthalene is converted into trichlor-a-naphthol by reducing agents; when treated with potassium iodide, iodine is liberated, amorphous insoluble compounds are obtained, and dichlorhydronaphthaquinone appears to be formed. It yields a mixture of various nitrogenous compounds when treated with hydroxylamine

hydrochloride, and combines with aniline to form chloranilidonaphthaquinoneanilide (see below). CO — CCI2 Pentachloroketohydronaphthalene, C.H.<CC CHCI>, is obtained by saturating a glacial acetic acid solution of 2-naphthol with chlorine in the cold. It is readily soluble in hot benzene, from which it crystallises in colourless, almost right-angled, monoclinic plates, melting at 156-157°; it is very sparingly soluble in ether, sparingly in alcohol, but more readily in hot glacial acetic acid, from which it crystallises in hard, thick forms. When heated above its melting point, it becomes slightly coloured, and at about 200-220° evolution of hydrogen chloride commences. It is readily converted into tetrachloroketonaphthalene, and yields, therefore, with various reagents the same products as the two tetrachloroketones. Stannous chloride transforms it into trichloroketone, which on further reduction gives a-B-dichlor-a-naphthol. Alkaline sulphites, in acetic acid solution, and phenylhydrazine, convert it into trichlor-a-naphthol; potassium iodide acts similarly, tetrachloroketone being first formed. By continued boiling with alcohol, it yields small quantities of tetrachloroketonaphthalene, part of which is further transformed into dichlora-naphthaquinone. This last-named compound is obtained almost quantitatively on heating the pentachloride in sealed tubes at 120130° with dilute alcohol or dilute acetic acid. When the pentachloride is treated with alkalis, the products, which vary according to the conditions of the experiment, are the same as those produced from tetrachloroketonaphthalene.

B-B-Chloranilidonaphthaquinone anilide, CH<-C(NPh) CCI, is COC(NHPh)

formed when aniline is added to an alcoholic solution of the pentachloroketone; it crystallises from benzene in dark-red, shining needles, which melt at 157°, and are only sparingly soluble in alcohol and glacial acetic acid. The salts of this base are bluish-black, and are readily decomposed by alcohol or water. The platinochloride, (C22H1CIN2O)2, H2PtCle, crystallises in small black-violet leaves with a metallic lustre. The anilide yields chloranilidonaphthaquinone when boiled with alcoholic hydrochloric acid.

Hexachloroketohydronaphthalene, C.H.<CCC, is obtained by heating the tetrachloride with manganese dioxide and hydrochloric acid; when crystallised slowly from glacial acetic acid, it forms thick, hard, seemingly monoclinic forms, but when crystallisation proceeds slowly, long striated needles are obtained. It is readily soluble in benzene and hot alcohol, sparingly soluble in ether, and melts at 130°; when heated above this temperature, it loses chlorine. This compound is tolerably stable, it liberates iodine from potassium iodide only slowly, and does not react with aniline; it is converted into trichlor-a-naphthol by the action of reducing agents. When treated

with alkalis in alcoholic solution, the ring is split, and an acid, COOH CH, CO-CCI:CCl2, is obtained, which is identical with that produced from tetrachlorodiketonaphthalene (this vol., p. 490). This acid crystallises from dilute alcohol, or dilute acetic acid, in colour

less, acute-angled rhombohedra, or in leaves which melt at 127-128°. When heated with concentrated sulphuric acid, it loses hydrochloric acid, and is converted into a compound which 's probably a substituted hydrindenecarboxylic acid. F. S. K.

B-Tetrahydronaphthylamine. By E. BAMBERGER and R. MÜLLER (Ber., 21, 1112—1125; compare this vol., pp. 159, 599).—In its behaviour towards diazobenzene chloride, B-tetrahydronaphthylamine resembles the non-aromatic amines, and yields a diazoamiduderivative, CoH NH N2Ph, which combines with picric acid in ethereal solution to form a picrate crystallising in lustrous, ruby-red needles and melting at 118°. Diazoamidotetrahydro-ß-naphthylamine is explosive, is volatile with steam, and when heated with dilute acids is decomposed for the most part into nitrogen, aniline, and dihydronaphthalene, a small quantity of B-tetrahydronaphthylamine and, probably, phenol being also formed. The tetrahydro-base is not attacked when boiled even for a day with hydrobromic acid (containing 47 8 per cent. of hydrogen bromide), but when heated with the acid at 150-160° is slowly decomposed into naphthalene, ammonia, and hydrogen; a similar result is also obtained by heating the base in sealed tubes at 80-100° above its boiling point for several days. The nitrite does not decompose below 160°, but when heated at 180190° is converted into nitrogen, water, and dihydronaphthalene, together with some ammonia formed by a secondary reaction. The aqueous solution of a mixture of the tetrahydro-base and nitrous acid in molecular proportion is not affected by prolonged boiling, and only suffers decomposition to a slight extent when heated at 120-130° for 20 hours, naphthalene being formed; the solution of a similar mixture in dilute sulphuric acid (1 : 10) is, however, less stable, and decomposes on warming with the production of naphthalene and a small quantity of an oil. The formation of naphthalene, taken in conjunction with the fact that a certain proportion of the tetrahydro-base remains unchanged in these decompositions, renders it probable that the reaction proceeds normally with the formation of nitrogen, water, and a hydronaphthol, which then decomposes into water and dihydronaphthalene, the latter being finally oxidised to naphthalene at the expense of a portion of the nitrous acid. To avoid if possible this secondary reaction, amyl nitrite was employed as the diazotising agent instead of nitrous acid, with the result that dihydronaphthalene, amyl alcohol, nitrogen, and water were obtained.

Acetyltetrahydro-ß-naphthylamine does not react with bromine in chloroform solution at 0°, from which the authors conclude that one of the two benzene nuclei is completely hydrogenated. To determine which, the tetrahydro-base was oxidised by suspending 3 grams in 250 c.c. of water containing a small quantity of sodium carbonate in solution, cooling to 10-12°, and adding in small quantities at a time 9 to 10 grams of a 4 per cent. permanganate solution; much ammonia escaped, and phthalic acid, together with Gabriel and Michael's hydrocinnamorthocarboxylic acid, COOH·CH, CH, CH, COOH (Abstr., 1878, 426; this vol., p. 150), which constitutes the chief product

.

:

:

under these conditions, were obtained, hence B-tetrahydronaphthylamine has the constitution [H, H2: H,NH, H2 = 12:34]. Valeryl-B-naphthylamine, CH, NH.CO.C,H,, is formed in small quantity by the action of sodium on a boiling solution of B-naphthylamine in valeric acid; it crystallises in long, vitreous prisms, and melts at 138.5°. W. P. W.

10

Derivatives of Diamido-a-naphthol. By S. MEERSON (Ber., 21, 1195-1199).-Diamido-a-naphthol hydrochloride, OH C10H5(NH2,HCl)2, can be prepared from the staunochloride obtained when Martius' yellow is reduced with tin and hydrochloric acid, by suspending it in water, precipitating the tin with hydrogen sulphide, evaporating the filtrate in a vacuum, and treating the residue with concentrated hydrochloric acid. It crystallises in colourless, microscopic tables, and is fairly stable in the dry state. When treated with anhydrous sodium acetate and acetic anhydride, it is converted into triacetyldiamido-a-naphthol, CoHs(OAc) (NHAc)2, which crystallises from acetic acid in white, microscopic needles, melts at 280° with decomposition, and is insoluble in water, sparingly soluble in boiling alcohol. It dissolves also in dilute aqueous potash with a red colour, and is oxidised to acetamidonaphthaquinone, CHO NHAc, when the solution is acidified with hydrochloric acid and treated with ferric chloride. The quinone crystallises from alcohol in lustrous, goldenyellow scales, and melts at 198° with decomposition.

Nitrotriacetyldiamido-a-naphthol, NO2 CH,(OAc) (NHAc)2, is obtained when triacetyldiamido-a-naphthol suspended in acetic acid is treated in the cold with nitric acid (sp. gr. = 148) until solution occurs. It is a yellow, granular powder, melts at 235° with decomposition, and on oxidation with potassium permanganate yields phthalic acid. Fuming hydrochloric acid dissolves it on warming with the formation of nitrodiamidoethenyl-a-naphthol hydrochloride, CMe<>C1H ̧(NO2)·NH2,HC1 [O : N : NO2 : NH2 = 1 : 2 : 3 : 4], which crystallises in long, slender, lustrous, citron-yellow needles, and yields a platinochloride, (C12H9N3O3)2,H2PtCle, crystallising in dark-yellow needles. On treatment with water, the hydrochloride decomposes, yielding the base, which has a beautiful scarlet colour, and is only sparingly soluble in alcohol; by boiling with very dilute aqueous potash, it is converted into hydroxynitroethenylamido-a-naphthol,

>CH.(NO2) OH; this crystallises in slender, brown needles,

and melts at 163° with decomposition.

Acetamidonaphthaquinoneacetimide, NAC CHO NHAc, is prepared by the action of anhydrous sodium acetate and acetic anhydride on diimido-a-naphthol hydrochloride. It crystallises from alcohol in thick, dark-yellow prisms, and melts at 178° with decomposition. On oxidation with nitric acid (sp. gr. = 148), it yields the acetamidonaphthaquinone already described, and on treatment with bromine (1 mol.) in acetic acid solution is converted into bromacetamidonaphthaquinone, CoHO2Br.NHAc, which crystallises from alcohol in lustrous, golden-yellow needles, and melts at 205° with decomposition.

W. P. W.