| abstract |
Novel intermediates of the formula <IMAGE> where R1 and R2 are each (C1-C4)alkyl or taken together are (C2-C4)alkylene, and their use in a process for preparation of compounds of the formula <IMAGE> (I) where R is (C1-C6)alkyl or (CH2)nAr, Ar is phenyl or phenyl monosubstituted by Cl, Br, F, CH3 or OCH3 and n is 2 to 4; which comprises contacting one of said intermediates with an amidine of formula <IMAGE> in the presence of reaction inert solvent and base; and a process for preparing a further intermediate, 1,2-dichloro-1-buten-3-one. |