Patent ID: RE38796

Claim:
A process for producing a 3-amino-2-oxo-1-halogenopropane derivative represented by formula (V) wherein R s represents hydrogen, an optionally substituted alkyl group having from 1 to 10 carbon atoms, an optionally substituted aryl group having from 6 to 15 carbon atoms, an optionally substituted aralkyl group having from 7 to 20 carbon atoms, or the above-mentioned groups containing a hetero atom in the carbon skeleton; P 1 and P 2 , independently from each other, represent hydrogen or an amino-protecting group, or P 1 and P 2 together form a difunctional amino-protecting group, and at least one of P 1 and P 2 is not hydrogen; and X represents a halogen atom other than fluorine or its salt, which comprises: (i) reacting a compound represented by formula (I) wherein R s , P 1 , and P 2 are as defined above, and E 1 represents an alkoxy ester residue having from 1 to 10 carbon atoms, a phenoxy or benzyloxy group, which may have a substituent in the ring, an ester residue of N-oxysuccinimide or 1-oxybenzotriazole, an active thioester residue, an imidazolyl group or a residue capable of forming an acid halide, an acid anhydride or an acid azido, with an alkali metal enolate of an acetate to obtain a compound represented by formula (II) wherein R s , P 1 , and P 2 are as defined above, and R 1 represents an optionally substituted alkyl group having from 1 to 10 carbon atoms, an optionally substituted aryl group having from 6 to 15 carbon atoms, an optionally substituted aralkyl group having from 7 to 20 carbon atoms, a trialkylsilyl group having from 4 to 10 carbon atoms, a phenyldialkylsilyl group having 8 to 10 carbon atoms or a diphenylalkylsilyl group having 13 to 15 carbon atoms; (ii) reacting the compound of formula (II) with a halogenating agent for halogenation of the 2-position to form a 4-amino-3-oxo-2-halogenobutanoic acid ester derivative represented by formula (III) wherein R s , P 1 , P 2 , R 1 and X are as defined above; (iii) further hydrolyzing the resulting compound of formula (III), to obtain a hydrolyzate; and (iv) decarboxylating said hydrolyzate, to obtain said compound of formula (V).