DD238611A1 - PROCESS FOR PREPARING SPIROBENZO-1,4-2H-OXAZINES AND THEIR COLOR SALTS - Google Patents

Abstract

The invention relates to a process for the preparation of spirobenzo-1,4-oxazines and their color salts of the general formulas IV and VI, which are significant as dyes or Farbstoffprecursoren for the long-wavelength spectral range. The invention has the object of finding a simple process for the preparation of the hitherto unknown spirobenzo-1,4-2H-oxazines and their color salts. The object is achieved in accordance with the invention by condensing 2-nitrosophenols of the formula I with activated methylene bases or their salts of the formula II or III in the presence of acidic or basic catalysts and precipitating the polymethine salt of the formula IV with perchloric acid or a hydrohalic acid. The spirobenzo-1,4-2H-oxazines of the formula V can be obtained either from the polymethine salts by reaction with a base or directly from the condensation products by treatment with a digested caustic.

Description

with activated methyl bases of the general formula II,

or in a mixture with these can be reacted, wherein

R ^{1 is} one or more alkyl groups, halogen, nitrile, nitro, O-alkyl or O-acyl,

R ² , R ^{3 may be the} same or different and are hydrogen, alkyl or together cycloalkyl or cycloheteroalkyl,

R ⁴ , R ^{5 may be the} same or different and are hydrogen, alkyl, alkylsulfonate or aryl,

R ^{6 is} one or more alkyl, O-alkyl, O-acyl, nitro or nitrile,

X is dialkylmethylene, oxygen, sulfur or selenium and.

Z "an acid radical anion, for example CIOj;. Cl", Br ", ZnClJ, CH ₃ SOJ, p-toluenesulfonate or FeClJ

can mean.

The condensation reaction can be carried out in any organic solvent, preferably in ethanol or glacial acetic acid

be performed. Suitable catalysts are organic bases, such as piperidine, pyridine or triethylamine, acids, for example glacial acetic acid, hydrogen chloride, perchloric acid or tetrafluoroboric acid or Lewis acids, for example aluminum chloride,

Zinc chloride or ferric chloride, suitable.

The condensation proceeds in high yield, and the obtained Polymethinfarbsalze or spirobenzo-1,4-2H-oxazines are easily obtained by recrystallization from ethanol, chloroform, glacial acetic acid, nitromethane or acetonitrile in high purity.

The spirobenzo-1,4-2H-oxazines are soluble in common organic solvents, optionally in solution form an equilibrium between the ring-closed spiro form and the ring-open polymethine form and are therefore more or less colored.

The Polymethinfarbsalze absorb in the long-wavelength spectral range with high extinction coefficients. With the

Spirobenzo-1,4-2H-oxazines or their polymethine salt salts can be prepared for the first time in a simple manner with high yields and high purity in a single reaction stage.

embodiments

The process according to the invention for the preparation of spirobenzo-1,4-2H-oxazines or the polymethine salt salts is explained below without restricting its utility in any way.

example 1

0.025 mol of 2-nitroso-5-diethylaminophenol and 0.04 mol of 1,3,3-trimethyl-2-methylenindoline are dissolved in 100 ml of ethanol and boiled for 5 hours after addition of 1 ml of glacial acetic acid at reflux.

After cooling, 1 ml of perchloric acid (75%) was added, the precipitate was filtered off with suction and from acetonitrile

recrystallized.

Dark blue to black crystals are obtained whose elemental analysis corresponds to the color salt of type IV (Z = CIOJ; R ¹ = R ⁵ = R ⁶ = H; R ² = R ³ = C ₂ H ₅ ; R ⁴ = CH ₃ and X = I) > C (CH ₃ J ₂ ) j.

Example 2

The procedure is analogous to Example 1, instead of the 1.3.3-trimethyl-methylenindoline 2-methyl-3-ethylbenzthiazoliumjodid is used.

According to the results of the elemental analyzes, a type IV color salt (Z = J ~; R ¹ = R ⁵ = R ⁶ = H; R ² = R ³ = R ⁴ = C ₂ H ₅ and X = S) is formed.

Example 3

An ethanolic solution of the dye according to embodiment no. 1 is treated with 1 N aqueous NaOH. After concentration of the solution, the mixture is extracted with benzene, washed with dil. NaOH and then with dist. Water. After the organic phase has been dried with CaCl ₂ , it is concentrated and the soon to be precipitated end product is filtered off with suction

The resulting pale yellow crystals correspond in their elemental analysis and the photochemical behavior spiropyranes of the type V (R ¹ = R ⁵ = R ⁶ = H; R ² = R ³ = C ₂ H ₅ ; R ⁴ = "CH ₃ and X = I> C (CH ₃ T ₂ ) T

Claims (3)

Invention claim: R ³ 17 R ¹ may be the same or different alkyl, halogen, nitrile, nitro, O-alkyl or O-acyl, R ² , R ³ and hydrogen, alkyl or together cycloalkyl or cycloheteroalkyl, R ⁴ , R ^{5 be the} same or different and hydrogen, alkyl, alkylsulfonate or aryl, R ^{6 is} one or more alkyl, O-alkyl, O-acyl, nitro or nitrile, X dialkylmethylene, oxygen, sulfur or selenium and Z "an acid residue anion eg CIOJ, CHBr", BF ^ , ZnCIJ, CH ₃ SOY, FeClI or p-toluenesulfonate
may mean, characterized in that active methylene bases of the general formula II II or their salts of the general formula Ml III in the presence of acidic or basic catalysts with 2-nitroso-4-amino-phenols of general formula I. -3- Ζ3ΒΟΊΊ II Λ Rl .. or their salts of general formula I. "CH ₂ -R ⁵ Ζ" condensed in the presence of acidic or basic catalysts and optionally with an acid HZ Polymethinfarbsalze the general formula IV IR ² R ³ IV be precipitated, or that the condensation products by treatment with a dilute base, optionally without previously isolating them, directly to the spirobenzo-1,4-2H-oxazines of the general formula ^ /, optionally also in the ring-opened form of the general formula Vl NR ² R ³ 2. A process for the preparation of spirobenzo-1,4-2H-oxazines and their color salts according to item 1, characterized in that c is any organic solvent, preferably alcohol or glacial acetic acid, is used. -2- 238 6 R ¹ condensed and with an acid HY, the Polymethinfarbsalze the general formula IV are precipitated, or that the condensation products by treatment with a dilute liquor directly, without first isolating to Spirobenzo-1 2H-oxazine of the general formula V are reacted, or the Spirobenzo 1,4-2H-oxazines of the general formula V ai the Polymethinfarbsalzen of the general formula IV are represented by reaction with a base. 3. A process for the preparation of spirobenzo-1,4-2H-oxazines and their color salts according to item 1 and 2, characterized dadui that as catalysts, organic bases, preferably piperidine, or acids, preferably glacial acetic or chlorinated or else Lewis acids, preferably aluminum chloride, iron -lll-chloride or zinc chloride can be used. Field of application of the invention The invention relates to a process for the preparation of spirobenzo-1,4-2H-oxazines and their color salts. Spirobenzo-1,4-2r oxazines represent in their ring-opened form, deep-colored polymethine dyes or polymethine salt salts which absorb in the long wavelength spectral range with high extinction coefficients and which can therefore be used in manifold ways as dyes or dye precursors. Characteristic of the known technical solutions. Spirobenzo-1,4-2H-oxazines and their color salts represent a hitherto unknown class of substance. With the method according to the invention, the class of compounds can be presented for the first time. Object of the invention The aim of the invention is to find a simple synthetic route for the preparation of spirobenzo-1,4-2H-oxazines and their color salts. Explanation of the essence of the invention It is the object of the invention to find a simple process for the preparation of spirobenzo-1,4-2H-oxazines and their Farbsa. The object is achieved in that 2-NitrosQ-4-aminophenols of the general formula I.