DD274826A1 - PROCESS FOR THE PREPARATION OF 4-ALKYL-BZW. 4-ARYLMERCAPTOSUBSTITUATED 1-ARYLAZO NAPHTHALENE - Google Patents

Abstract

The invention relates to a process for the preparation of 4-alkyl or 4-arylmercaptosubstituted 1-arylazo-naphthalenes. Such compounds can be used as dyes for Anfaerben of fibers and plastics. With the invention is to be achieved, the technically hitherto difficult to produce 4-alkyl or 4-arylmercaptosubstituierten 1-Arylazonaphthalene synthesize in a simple manner. This is done according to the invention in such a way that 1-arylazo-4-chloro-naphthalenes with a mercaptan at elevated temperature and possibly in the presence of a preferably aprotic dipolar solvent to 4-alkyl or 4-arylmercaptosubstituierten 1-arylazo-naphthalenes of the general formula type III, be implemented. Formula III

Description

Ar-N = N-f> SR

IiI,

wherein Ar and R! as the same as in formula I and II, are reacted.

Ausfuhrungibelsplele

The invention will be explained in more detail below with reference to the compounds synthesized in Table 1 and synthesized according to the illustration below.

0.1 mo! of 4-chloro-1-3-yl azo-naphthalene are mixed in 1 COmI DMF with 20 ml of mercaptan and boiled under reflux. The course of the reaction is monitored by thin-layer chromatography until no more eutergangsvefuindung is detectable. At this time, the reaction solution is allowed to cool and placed in 100 ml of dilute acetic acid. The precipitate is then filtered off with suction and recrystallized from methanol for purification.

Table I

4-alkyl or. 4-arylmercapto-substituted 1-arylazonaphthalene

arylazo 4-alkyl or Fp ⁰ C yield 4-arylmercapto % 4-NO ₇ -C ₆ H ₄ - Ci ₂ H ₂ S- 312 48.5 4-NO ₂ -C ₆ H ₄ - C ₆ H ₅ - 322-24 51.0 4-NO ₂ -C ₈ H ₄ - C ₄ H ₈ - 275-78 54.0 4-NO ₂ -C ₆ H ₄ - C ₆ Hg-CH ₂ - 298-300 56.5 2-CN-4-NOr-C _e Hr- CijH ₂ g 263 55.0 2-CN-4-nor-CeHj- C ₆ H ₆ - 299-301 56.0 2-CN-4-NOr-C _e Hr- C ₄ HjT 261 61.0 2-CN - ^ - NO ₂ -C ₈ H ₃ - C ₆ H ₆ -CH ₂ - 299 59.5 2,4 (NO ₂ J ₂ -C ₈ H ₃ - Ci ₂ H ₂₆ - 271 61.0 2.4 (NO ₁ Jr-C ₈ Hj- C ₆ H ₆ - 249 57.5 2,4 (NO ₂ J ₂ -C ₆ H ₃ - C ₄ Hg- 301-03 56.0 2,4 (NO ₂ Jr-C ₈ H ₁ - C ₆ H ₆ -CH ₂ - 305 57.0 4-CI-C ₆ H ₄ - Ci ₂ H ₂₆ - 312 59.5 4-CI-C ₆ H ₄ - C ₆ H ₆ - 267 60.0 4-CI-C ₆ H ₄ - C ₄ Hg- 317-19 62.0 4-Cl-C ₆ H ₄ - C ₆ H ₆ -CH ₂ - 249-51 61.5 benzothiazole Ci ₂ H ₂₆ - 251-53 61.5 benzothiazole C ₆ H ₅ - 283-85 55.0 benzothiazole C ₄ Hg- 291-95 57.0 Renzthiazol- C ₆ H ₆ -CH ₂ - " 322 59.5

Claims (1)

A process for the preparation of 4-alkyl- or 4-arylmercapto-substituted 1-arylazo-naphthalenes, characterized in that 4-chloro-arylazo-naphthalenes of the type I, which are relatively easily prepared from technically readily available 4-arylazo-1 naphthols can be prepared by reaction with POCl3 / DMF, wherein Ar is a simple unsubstituted or by any, but preferably by electron acceptor moieties such as NO ₂ or CN substituted aryl or heteroaryl, which may be modified by condensation of one or more benzo radicals, optionally with a Mercaptan of the general formula II, wherein R can represent any aliphatic or aromatic radical, at temperatures between 80 and 150 ⁰ C using a preferably dipolar aprotic solvent, such as DMF, DMSO, HMPT or CHaCN to compounds of the general type III reacted wherein Ar and R have the same meaning as in the formulas I u nd II. Field of application of the invention The invention relates to a process for the preparation of 4-alkyl or 4-aryl-substituted 1-arylazo-naphthalenes. Such compounds are important as dyes for dyeing fibers and plastics. Characteristic of the known technical solution It is known that 4-alkyl or 4-aryl-substituted 1-arylazo-naphthalenes are accessible by condensation according to mercapto-substituted aromatic amines with nitrosobenzene (WATSOW, DUTT, J. Chem. Soc. 1940,121). However, the said process has the disadvantage that the mercapto-substituted amines required for this purpose are technically not easy to prepare and in the required purity and a z.T. have considerable adverse health effects aio which practically precludes their use in the art. In addition, the preparation of nitrosobenzene necessary for the condensation is also associated with difficulties, which presumably consist in the fact that these compounds are usually obtained from the difficult-to-access N-aryl-hydroxybenzenes. Object of the invention The aim of the invention is to make the technically hitherto difficult to prepare and usable as dyes for dyeing fibers and plastics 4-aryl- or 4-alkylmercaptosubstituierten 1-arylazo-naphthalenes accessible in a simple manner. Explanation of the essence of invention The object of the invention is to make the previously not easily representable 4-alkyl- or 4-arylmercaptosubstituierten 1 Arylazonaphthalene accessible in a simple manner from readily available and easily manageable starting materials in high purity and good yields. According to the invention the object is achieved in that the easily and conveniently produced according to DD155986 from technically readily available starting materials 4-chloro-substituted 1-arylazo-naphthalene of the formula I, wherein Ar is a simple unsubstituiorten or by any, but preferably by Elektronenakzeptorgruppierungen such as NO ₂ or CN substituted aryl or heteroaryl radical, which may optionally be modified by the condensation of one or more benzo radicals, Ar-N-N-fVa with a mercaptan of the formula II R-SH Il wherein R is any aliphatic or aromatic radical which may in the former case consist of simple unbranched or branched carbon chains of one to eighteen atoms and in the latter case any simple unsubstituted phenyl radicals, in a preferably aprotic dipolar solvent such as DMF, DMSO, HMPTor acetonitrile, at temperatures between 80 and 15O ⁰ Czu compounds of the general formula III