abstract |
A method for producing a compound of formula (I) is provided, where R1, R2, R3, R4, R5 and R6 have the meanings defined in the description, which includes the step of reacting the acrylic acid chloride of formula (II '), where R1, R2, R3, R4, R5 and R6 have the meanings as defined herein, with aqueous hydroxylamine and possibly converting the resulting compound into its acid addition salt. |