ES266636A1 - Procedure for preparing new amino acid compounds (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Procedure for preparing new amino acid compounds of the formula: ** (See formula) ** wherein R1 is a lower alkyl, R2 is selected from the group consisting of hydrogen and alkyl, R3 and R4 are selected from the group consisting of hydrogen and lower alkanoyl, X is selected from the group consisting of hydrogen, halogen, alkyl and trifluoromethyl , X being in the para position, with respect to the amino acid side chain, when it is other than hydrogen, and n is a positive integer less than 4, said compound being in the absolute spatial configuration L (left) and substantially free of the enantiomorph of absolute configuration D (right), which consists of (a) reacting a compound of the formula: ** (See formula) ** wherein m is 0 or 1, with a water soluble cyanide salt and ammonium carbonate or an ammonium halide, heating the reactants in aqueous solution to form an intermediate product selected from the group consisting of compounds of structure: ** (See formula) ** and compounds of formula: ** (See formula) ** (b) in the case of the compounds of the formula II, treat with an aqueous acid to form a structure compound; ** (See formula) ** and heating this amide with aqueous halohydrate under pressure to form a structure compound ** (See formula) ** (c) in the case of the compounds of the formula III, heating said compound with a reagent selected from the group consisting of aqueous bases and aqueous concentrated hydrohalic acids, the product of aqueous bases being a compound of the formula: ** (See formula) ** and heating said compound VI with aqueous hydrohalic acid to form, as in the case of direct heating of the compounds of formula III with aqueous halohydric acid, compounds of formula V. ** (See formula) ** (d) if desired, form compounds of the formula from the compounds of formula V: ** (See formula) ** heating said compounds of formula V with an alkanol in the presence of a mineral acid (e) If it is desired to form from the compounds of formula V, the compounds of formula, ** (See formula) ** heating the compounds of formula V with a lower alkanoic anhydride in the presence of a proton acceptor; Y (f) effecting the resolution, by any desired method, in its optically active compounds of one of the compounds of formulas II, III, IV, V, VI, VII, or VIII and completing, when necessary, the synthesis of the compound desired by the preceding routes or carry out the hydrolysis, when necessary, by heating with aqueous caustic, using the isolated compound of the absolute configuration L (left). (Machine-translation by Google Translate, not legally binding)