GB658413A - Improvements in or relating to aldehydo compounds and methods of preparing the same - Google Patents

Abstract

Aldehydes of the formula <FORM:0658413/IV (b)/1> where R is a substituted amino group from which the free amino group may be regenerated, R1 is CN or COOalk, and "alk" is an alkyl group of 1-4 carbon atoms, are obtained by treating a compound of the formula CHRR1.COOalk with an allyl halide in the presence of an alkaline catalyst to give CH2=CH-CH2-CRR1-COOalk, converting this into the ozonide by treatment with ozone, and reducing the ozonide by known methods. The aldehydes may then be converted into their acetals. R may be phthalimido, acylamino or diacylamino, e.g. acetamido, benzamido or benzene sulphonamido. Details are given of the reaction between ethyl acetamido-malonate and allyl bromide in alcohol (to which sodium has been added) to give ethyl 2 - acetamido - 2 - carbethoxy - 4 - pentenoate. This is ozonized and catalytically hydrogenated with palladium on charcoal to give beta-acetamido-beta-beta-di-carbethoxy-propionaldehyde which is isolated as its 2 : 4-dinitrophenylhydrazone. Other reactants mentioned are allyl chloride, allyl iodide and ethyl acetamido-cyanacetate. Amino-acids.-The aldehydes produced as above may be used in the synthesis of amino-acids as follows: The product of the example is (1) condensed with ethyl cyanacetate and hydrogenated to give CH3COHN-C(COOEt)2-CH2-CH2-CH(CN) -COOEt, which is hydrolysed to alpha-acetamido-delta-cyano-valeric acid; the latter is reduced to the delta-amino-methyl compound and hydrolysed to yield lysine; (2) converted into its cyanhydrin and dehydrated to give CH3CONH-C(COOEt)2-CH : CH-CN which is (a) hydrogenated and hydrolysed to glutatic acid; or (b) reduced to the saturated aminomethyl compound and hydrolysed to ornithine; (3) oxidized to the corresponding carboxylic acid and hydrolysed to aspartic acid; (4) condensed with phenylhydrazine and ring-closed to ethyl alpha-acetamido-alpha-carbethoxy-3-indolyl-acetate which is hydrolysed to alpha-amino-3-indolyl-acetic acid. The Specification as open to inspection under Sect. 91 refers to the preparation by the above method of aldehydes CRR1R2-CH2-CHO, where R and R1 are hydrogen, carboxylic acid or ester, CONH2, CONHR or CN (but not both hydrogen), and R2 is substituted amino, e.g. methylamino, phenylamino and N-carbobenzoxy in addition to the groups specified above. The esterifying group in the carboxyl group and the substituent in CONHR may be methyl, ethyl, propyl, phenyl, benzyl, toluyl or other hydrocarbon radicals. These aldehydes may be converted into acetals, after which the group R may be converted to H by decarboxylation and the acetal then hydrolysed back to the aldehyde. Similarly R in the acetal may be converted into an amide or nitrile group before hydrolysis. This subject-matter does not appear in the Specification as accepted.