IL27281A - Substituted benzonitriles and their preparation - Google Patents

Description

2 2 The present invention consists in new of the general ON in which is an alkoxy radical of from 1 to 5 carbon is a or amino group and X is Examples of the moiety of the alkoxy group are Examples of the halogen are chlorine and e also consists in a process for the preparation of compounds of I by the dehydration of the corresponding or of the general in which and have the same meaning as in formula The dehydration reaction is preferably carried out at elevated The starting material may be heated by The dehydration may be promoted by contacting the vapours of the starting material at a high temperature with aluminium or the Or the starting material may also be heated together with a dehydrating such as phosphorus phosphorus oxyhalide phorus oxychloride or phosphorus thionyl dicyclohexylcarbodiimide catechuylphosphorus molecular sieves and the The dehydrating agent may instead be a mixture of a such as dimethylaniline and the with phosphorus chlorocarbonic acid trifluoroacetic phosgene and the dehydration by means of a dehydrating agent may be effected in an inert solvent such as petroleum carbon tetrachloride and the Where a of formula II is dehydrated with the aid of a dehydrating which duces an acyl radical amino group in the and as may happen with phosphorus oxyhalide a carboxylic acid chlorocarbonic acid alkyl phosgene and the the resultant compound is hydrolyzed with an such as hydrochloric sulfuric acid and the or with a such as sodium sodium and the The benzamides of formula serving as materials in the above process can be prepared by known by reacting an ester of alkanoylamino or acid with 3y another process the new benzonitriles of the formula I in ich is may be prepared in that a is reacted with a nitrite salt in the presence of an the resulting salt is converted into the corresponding the latter is alkylated and the t hus formed first two stages of this process are described in Israel Patent Specifications 26949 The last of the process can be represented by the in which and X have the same meaning as in In the last stage of this the nitric acid ma replaced by a substance which produces nitric acid by reaction with such dinitrogen pentoxide or dinitrogen or by reaction with an such as sodium potassium nitrate or calcium In these the reaction ture has to contain water or an The new compounds of this invention are useful as intermediates in production of compounds possessing valuable pharmacological and antiemetic for example The invention is illustrated by the following Examples to which it is not EXAMPLE 1 10 g of and 25 ml in a of nitric acid are steel The vessel is sealed and heated at for 13 hours when the reaction is The reaction mixture is then discharged from the nd the filter residue is washed with 20 ml of The washed material is crushed in a During this operation it is extracted four times with 25 ml of aqueous sodium and each time The last filter residue is washed well with After this is dissolved in 80 ml of heated with 1 of active carbon on water the carbon is filtered off and the solution is evaporated to From g of the residue a sample of g is chromatographed on a column of silica and el ted with The starting is contained in the initial fraction of 50 From the subsequent in an amount 105 is in the form of crystals melting at 173 to yield on the yield the chromatographed g for 2 15 of acid methyl ester and 75 ml of ammonia were heated in a pressure tube at for reaction mixture was the crystals thereby formed were collected by washed with water and recrystallized from and the yield was of melting at 3 100 ml of phosphorus oxychloride was added to g of mixture was stirred at for when the reaction was Then an of phosphorus oxychloride was removed by distillation The ethyl acetate was distilled off and the residue was extracted with aqueous sodium the extract was removed fey the residue was washed with water and in a mixture of 60 ml of hydrochloric acid and 120 ml of The solution was refluxed on a water for 3 Upon distillation of the ethanol there remained hydrochloride which was kneaded well in a mortar and treated with aqueous sodium The undissolved free base was collected by washed with water and The of crude melting at was 12 g This was from Analysis Calculated 4 A mixture of 20 ml of phosphorus oxychloride and g of was stirred at for After the excess of phosphorus oxychloride was distilled off under reduced 20 ml o was whereupon crystals which collected by washed with water and dried to give g of melting at Analysis Calculated for insufficientOCRQuality

Claims (1)

1. CLAIMS Benzonitriles of the general in which is an alkoxy radical of from 1 to 5 carbon is a nitro or amino and X is a halogen A process for the preparation of benzonitriles of the general formula I in wherein a of the general in which X have the same meaning as in Claim is A proeess the preparation of benzonitriles of the general I in Claim 1 in which is a nitro wherein a compound of the general is heated with nitric acid under elevated For the Applicants OOH PARTNERS J insufficientOCRQuality