GB660350A - Improvements in or relating to aldehydo compounds and processes of producing the same - Google Patents

Abstract

Aldehydes of the formula <FORM:0660350/IV (b)/1> where R is an N-acyl group attached via its nitrogen atom, R1 is alkyl of 1-4 carbon atoms, R2 is CN or COOR1 and R3 is H or methyl, are obtained (1) by reacting CHRR2. COOR1 with R3.CH : CH.CHO in the presence of an alkaline catalyst, preferably at a low temperature, and subsequently neutralizing before isolating the aldehyde; (2) when R2 is COOR1 and R3 is H, by reducing R.C(COOR1)2 CH2.CH2.CN with stannous halide and hydrogen halide to give an aldimine complex which is then hydrolysed; (3) when R3 is H, by treating CRR2X.COOR1 with Hal.CH2.CH2. CH(OR4)2 and hydrolysing the resultant acetal; X is an alkali metal and R4 is alkyl of 1-4 carbon atoms; or (4) when R3 is H, by treating CRR2X.COOR1 with a compound having the grouping Hal-CH2.CH2.CH : CH- to give CRR2(COOR1).CH2.CH2.CH : CH- which is then ozonized. The acyl group in R is derived from a carboxylic acid, e.g. acetic acid, or R may be phthalimido. The starting material for method (2) may be obtained from R.CH(COOR1)2 and acrylonitrile. The alkaline catalyst for method (1) may be sodium ethoxide or other alkali alkoxide, alkali oxide or hydroxide, piperidine or a quaternary ammonium hydroxide. The aldehydes may be isolated as their phenylhydrazones or 2 : 4-dinitrophenylhydrazones. Examples are given of the various processes. Amino-acids may be obtained from the aldehydes as follows: (1) condensation with phenylhydrazine and ring-closure with boron trifluoride, zinc chloride or sulphuric acid to give <FORM:0660350/IV (b)/2> which is then hydrolysed to the dibasic acid and decarboxylated to N-acyl-tryptophane which is finally hydrolysed to tryptophane; (2) conversion to cyanhydrin, dehydration to unsaturated nitrile, hydrogenation to <FORM:0660350/IV (b)/3> and hydrolysis to lysine; (3) reduction to the corresponding alcohol, conversion into cyanide via halide, hydrogenation to the compound specified in (2) and hydrolysis to lysine; (4) oxidation to the corresponding acid, hydrolysis to yield N-acyl-glutamic acid and finally glutamic acid; (5) hydrolysis of the N-acyl group with simultaneous ring closure to D 1-pyrroline-5-carboxylic acid or 5 : 5-dicarboxylic acid which is reduced (and decarboxylated if necessary) to give proline; (6) conversion into oxime, aldimine, phenylhydrazone or semi-carbazone, reduction to amine and hydrolysis with decarboxylation to yield ornithine. The Specification as open to inspection under Sect. 91 refers to the production of compounds to the formula CRR1R2-CH2-CH2-Y, where R and R1 are H, carboxyl, ester, amide or nitrile (but not both H or amide), R2 is substituted amino and Y is an aldehyde or acetal group. They are made by the above methods with certain restrictions as to R and R1, viz; no H or free carboxyl in method (1), not nitrile in method (2) and not free carboxyl in methods (3) and (4). In method (1), substituted compounds of the general formula <FORM:0660350/IV (b)/4> may be obtained by using the appropriate unsaturated aldehydes and ketones, e.g. methyl vinyl ketone. When R and/or R1 is ester, the esterifying group may be methyl, ethyl, propyl, phenyl, benzyl, toluyl or other organic group. R2 may be any substituted amino group, e.g. methylamino, phenylamino, benzmido, abenzene sulphonamido, N-carbobenzoxy or RCONH where R is as specified for the ester group above, including diacylamino groups. The aldehyde group in the products may be converted into an acetal group. This subject-matter does not appear in the Specification as accepted.