Preparation of essentially isomerically pure methyl E-2-(2-aryloxymethylenephenyl)crotonates, and intermediates therefor.

    公开(公告)号:ZA963497B

    公开(公告)日:1997-11-03

    申请号:ZA963497

    申请日:1996-05-03

    Applicant: BASF AG

    Abstract: PCT No. PCT/EP96/01689 Sec. 371 Date Oct. 9, 1997 Sec. 102(e) Date Oct. 9, 1997 PCT Filed Apr. 23, 1996 PCT Pub. No. WO96/34847 PCT Pub. Date Nov. 7, 1996A process for the preparation of essentially isomerically pure methyl E-2-(2-aryloxymethylenephenyl)crotonates of the formula Ia Ia where R is an aromatic radical and R' is a C1-C3-alkyl group, which comprises first converting a suitable methyl 2-(2-aryloxymethylenephenyl)- alpha -ketoacetate with an alkyl metal compound of the formula IIIM-CH2-R'IIIwhere M is a metal ion equivalent into the corresponding methyl 2-(2-aryloxymethylenephenyl)- alpha -hydroxybutyrate of the formula IV, subsequently dehydrating IV in the presence of an acid to give a mixture of methyl E- and Z-2-(2-aryloxymethylenephenyl)crotonates and, subsequently, converting this mixture in the presence of a base in an inert polar solvent into the essentially isomerically pure methyl E-2-(2-aryloxymethylenephenyl)crotonate Ia.

    Methyl alpha-phenylbutenoates
    37.
    发明专利

    公开(公告)号:AU682963B2

    公开(公告)日:1997-10-23

    申请号:AU2448195

    申请日:1995-04-25

    Applicant: BASF AG

    Abstract: PCT No. PCT/EP95/01554 Sec. 371 Date Oct. 31, 1996 Sec. 102(e) Date Oct. 31, 1996 PCT Filed Apr. 25, 1995 PCT Pub. No. WO95/29896 PCT Pub. Date Nov. 9, 1995Methyl alpha -phenylbutenoates of the formula I I where +E,uns --+EE is a single or double bond and the index and the substituents have the following meanings: n is 0, 1, 2, 3 or 4; R1 is nitro, cyano, halogen, alkyl, haloalkyl or alkoxy; R2 is hydrogen, nitro, cyano, halogen, alkyl, haloalkyl, alkoxy, alkylthio or alkoxycarbonyl; R3 is unsubst. or subst. alkyl, alkenyl or alkynyl; an unsubst. or subst. saturated or mono-or diunsaturated ring which, in addition to carbon atoms, can contain one to three of the following heteroatoms as ring members: oxygen, sulfur and nitrogen, or an unsubst. or subst. mono- or binuclear aromatic radical which, in addition to carbon atoms, can contain one to four nitrogen atoms or one or two nitrogen atoms and an oxygen or sulfur atom or an oxygen or sulfur atom as ring members, processes for their preparation and their use are described.

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