GB1324571A - Thallium salts of hydroxy-chromones and the preparation of bis- chromones therefrom - Google Patents

Abstract

1324571 Chromones FISONS Ltd 3 Jan 1972 [22 Jan 1971] 2924/71 Heading C2C Novel chromones of Formula (II) in which R<SP>1</SP>, R<SP>2</SP> and R<SP>3</SP> may each be H, halo, alkyl, hydroxy, alkoxy or substituted alkyl or alkoxy, D is a carboxylic acid group or a group which may be hydrolysed thereto, e.g. an ester, may be obtained by reaction of a thallous alkoxide, e.g. thallous ethoxide, with a compound of Formula (IV) preferably in a solvent in which (II) is sparingly soluble and from which it is precipitated during the reaction, e.g. chloroform. Bis-chromones of the Formula (I) in which R<SP>1</SP>, R<SP>2</SP>, R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP> and R<SP>6</SP> may have any of the values defined for R<SP>1</SP> to R<SP>3</SP> above, X is a saturated or unsaturated, substituted or unsubstituted hydrocarbon chain which may be interrupted by a carbocyclic or heterocyclic ring or one or more oxygen atoms or carbonyl groups, may be obtained by reacting (II) with a compound of Formula (III) in which X<SP>1</SP>Y is such that on reaction with the T1 in (II) it leaves an X residue, Y being an anion forming group (e.g. halogen or p-toluenesulphonate or methane sulphonate) or together with X<SP>1</SP> forms an epoxide group. The compounds (I) are useful in the treatment of allergic asthma. Intermediate (III) may be obtained by reacting (II) with a compound Y<SP>1</SP>X<SP>2</SP>Y<SP>1</SP> in which X<SP>2</SP>Y<SP>1</SP> is such that on reaction with T1 it leaves a residue X<SP>1</SP>, Y<SP>1</SP> being an anion forming group or together with X<SP>2</SP> forming an epoxide group. (Thus Y<SP>1</SP>X<SP>2</SP>Y<SP>1</SP> may, for example, be dibromopentane or epichlorohydrin).