Patent GB-268830-A (GB)
Title: Manufacture of benzanthrones
IPC: C09B3/04
Filed: 1927-04-04
Abstract: 268,830. I. G. Farbenindustrie Akt.- Ges. April 3, 1926, [Convention date]. Samples furnished. Bz-Substituted-Lenzanthrones are produced by condensing, in presence of an acid condensing agent, a reduction product of anthraquinone, or of a substituted anthraquinone, containing oxygen in the meso-position, such as anthrone, anthranol, or oxanthranol, with a compound of the general formula where R=alkyl or aryl; R1=any monovalent residue such as hydrogen, alkyl, aryl, acyl, aroyl, or carboxylic ester group; R2=hydrogen, hydroxy, alkoxy, alkyl, or aryl; these compounds may be replaced by the corresponding compounds in which the double linkage is replaced by a single linkage with simultaneous addition of the elements of water or hydrogen halide; thus methylene-acetone CH3-CO-CH=CH2 may be replaced by ketobutanol CH3-CO-CH2-CH2OH and phenylvinylketone C6H5-CO-CH=CH2 by #-chlorpropiophenone C6H5-CO-CH2-CH2Cl : further, if in the compound Rand R2 are either hydroxy or alkoxy groups the condensation takes place readily even in the absence of an acid condensing agent. According to examples the following benzanthrone derivatives are obtained :-(1) Bz1- methylbenzanthrone from anthrone and methyleneacetone or ketobutanol CH3-CO-CH2-CH2OH, or from anthrone and sodium-hydroxymethyleneacetone or ethoxymethyleneacetylacetone, or from anthrone and ethoxymethyleneacetoaceticester by heating in quinoline; (2) phenylbenzanthrone from anthranol and methyleneacetophenone (phenylvinylketone,) or phenylketopropanol C6H5- CO-CH2-CH2OH, or from oxanthranol and #- chlorpropiophenone; (3) Bz1: Bz2-dimethylbenzanthrone from anthrone, and sodium (hydroxymethylene-ethyl)-methylketone CH3-CO-C(CH3) =CHONa. (4) Bz1-ethyl-Bb2-methylbenzanthrone from anthrone and sodium (hydroxymethyleneethyl)-ethyl ketone CH3-CH2-CO-C(CH3)= CHONa; (5) a Bz-diphenylbenzanthrone from anthrone and benzylideneacetophenone; (6) two isomeric Bz-methylphenylbenzanthrones from anthrone and benzylideneacetone and ethylideneacetophenone or 2-benzoylisopropylalcohol C6H5- CO-CH2-CHOH-CH3 respectively; (7) Bz1 : Bz3- dimethylbenzanthrone from anthrone and ethylideneacetone or hydracetylacetone CH3-CO-CH2- CHOH-CH3 ; (8) Bz1-p-methoxyphenylbenzanthrone by heating anthrone with p-methoxy-#- chloropropiophenone and then heating the intermediate product so produced with sulphuric acid; (9) Bz1-hydroxy-Bz2-acetylbenzanthrone or Bz1- hydroxy-Bz2-benzoylbenzanthrone from anthrone and hydroxymethyleneacetoacetic ester or hydroxymethylenebenzoylacetic ester respectively; (10) Bz1-hydroxy-Bz2-benzanthrone-carboxylic ester by heating anthrone with ethoxymethylenemalonic acid diethyl ester in quinoline; (11) Bz1-hydroxy-Bx2-phenylbenzanthrone from anthrone, and hydroxymethylenepbenylacetic ester. The condensations are effected, except where otherwise indicated, in solution in sulphuric acid or a mixture of sulphuric and glacial acetic acids. In place of reduction products of anthraquinone there may be used reduction products of substituted anthraquinones such as 2-methylanthrone or chloranthrone. The Specification, as open to inspection under Sect. 91 (3) (a) mentions also halogen, hydroxy, alkoxy, and aralkyl groups in the position R,. This Subject-matter does not appear in the Specification as accepted. Methyleneacetone is obtained by elimination of water from ketobutanol by the process described in Specification 19088/09. p-Methoxy-#-chlorpropiophenone is obtained by condensing #-chlorpropionylchloride with anisole in presence of aluminium chloride.