IL28825A - 9,10-dihydro-4h-benzo(4,5)cyclohepta(1,2-b)thiophen-(4)-one - Google Patents

Description

The present invention relates to a new thiophene derivative and to a process for its new thiophene derivative of the invention is has the formula This can serve as a starting material for the production of pharmaceutically active those described in Israel fatent Specification which compounds have the formulae prepared via the compounds in which and are hydrogen or lower radicals and are lower alkyl radicals or together a t methylene or pentamethylene the proviso that when is may form together with a or and when is may form together a dimethylene or trimethylene The invention also consists in a process for the preparation of the above acid is reduced to acid which latter is subjected to intramolecular ring Sodium amalgam in an a alcohol for example be used as reducing The ring closure is effected in the presence of a condensation agent such as sulfuric acid or a hosphoric the ring closure is effected by heating the acid with phosphoric acid into which phosphorus pentoxide has been The thie acid can be prepared in that is condensed with acid in an anhydrous solvent and in the presence of an alkaline condensation The invention is illustrated by the following Example g of chloride ram are o of heated to then phosphite is slowly added with stirring at the same and the mixture is heated for a further two hours at with The reaction mixture then distilled in a high phosphonate distils at mm acid 30 g of well dried sodium h e are added to a of g of phonate in 200 cc of freshly distilled dimethyl in a The temperature of the solution rises to in the course of the dissolving The flask is then placed in an ice bath a solution of 80 g of acid in 200 cc of dimethyl formamide is added dropwise with stirring at such a rate that the temperature remains between 35 and 40 and the stirring is then continued minutes at room 1600 cc of water are then added to the reaction solution whilst the latter is cooled a red oil The material is then made alkaline with potassium upon the oil the solution is extracted three times with benzene and the aqueous phase is carefully adjusted to a value of 4 at with hydrochloric The mixture is left to stand for several hours in a then the precipitated acid is filtered dried and from Its melting point is then The mother liquor is extracted three times with methylene the organic phase is dried over sodium sulphate and evaporated at 15 The residue is crystallized from whereby a further portion of the above acid is g of sodium are melted anhydrous thereafter 375 g of pure mercury added dropwise whilst the mixture is shaken at frequent By the developing heat the toluene is made to The mixture is then heated o to C with and as soon as the toluene has tilled is cooled to a temperature of The homogeneous amalgam is then covered with a solution of 20 g of acid in 150 cc of ethanol and the mixture is shaken for The mercury is then separated and washed twice with and the combined ethanolic solutions are diluted with 00 cc of The solution is filtered through highly purified diatomaceous acidified with hydrochloric acid and cooled to After acid is filtered off recrystallized from Melting point 59 cc of 8 phosphoric acid and 86 g of phosphorus pentoxide are stirred for 30 at then 20 g of powdered acid are introduced in the course of minutes at this The reaction mixture is stirred for a further two hours at 1 then poured into cc of the solution is filtered through highly purified diatomaceous earth and extracted three times methylene The organic phase is washed with 2 aqueous sodium dried over magnesium the methylene chloride is removed by evaporation and the residue ia distilled in a high The product is which distils as a green oil at insufficientOCRQuality

Claims (1)

1. particularly described and ascertained the nature of our said invention and in what the same is to he we declare that what we claim 4 28th July A process for the production of benzo which comprises subjecting to molecular ring 28th A process according to Glaim wherein the ring closure is effected with aid of a condensation A process according to wherein the condensatio agent is sulphuric acid or a polyphosphoric 28th A process for the production of benzo whieh comprises reducing acid to form aeid and subjecting the latter to intramolecular ring 29th July A process for the production of benzo substantially as herein described with reference the 29th July Dated this 24th day of For the Applicants insufficientOCRQuality