| abstract |
The invention relates to a method for the production of β-ketocarboxylic acid derivatives of formula (I) or the salts thereof, where X = NR', O or S, R, R', R1-R4 independently = H, alkyl, alkenyl, aryl or heteroaryl, by reaction of a diketene of formula (II) with a compound comprising an active hydrogen of formula ROH, NHRR' or RSH, characterised in that the reaction is continuously carried out in a microreactor. |