Herbicidal acylated di:ketonic cpds. prodn. - by rearrangement of corresp. enol ester in the presence of cyanide source

摘要

In the prodn. of an acylated cyclical diketonic cpd. (I) by rearrangement of the corresp. enol ester (II), the rearrangement is conducted in the presence of a cyanide source. Pref. either a catalytic amt. of cyanide source and a molar excess, w.r.t. (II) of a moderate base or a stoichiometric amt., w.r.t. (II) of KCN or LiCN, and a catalytic amt. of cyclical crown ether or acyclic analogue, is employed. (I) are pref. of formula (Ia), where R1 - R6 = H or 1-6C alkyl; or R1, R2 or R3 = RaOCO; or R1 + R2 or R3 + R4 = 3-6C alkylene; Ra = 1-4C alkyl or phenyl (opt. substd. by 2-5 Me gps.); R7 = halo, CN, 1-4C alkyl, 1-4C haloalkyl, RkD(O)n, 1-4C alkoxy or NO2; Rk = 1-4C alkyl; n = 0-2; R8-R10 = H, halo, 1-4C alkyl, 1-4C alkoxy, trifluoromethoxy, CN, NO2, 1-4C haloalkyl, 1-4C alkylthio, phenoxy or substd. phenoxy (substd. by halo and/or halomethyl), RbS(O)n, RcCONH, NRdRe, RfC(O) or SO2NRgRh; Rb = 1-4C alkyl, 1-4C haloalkyl, phenyl or benzyl; Rc = 1-4C alkyl; Rd, Re = H or 1-4C alkyl; Rf + H, 1-4C alkyl, 1-4C haloalkyl or 1-4C alkoxy; Rg and Rh = H or 1-4C alkyl; or R8 + R9 = a ring strcture with 2 adjacent C atoms of the phenyl ring to which they are attached.