Process for the preparation of 7-substituted 3-alkyl-3H-isobenzofuran-1-one derivatives
申请人:Syngenta Crop Protection, Inc.
公开号:US07307175B2
公开(公告)日:2007-12-11
Process for the preparation of compounds of formula (I) wherein R is halogen, R1O1R1S(O)n or (R1)2NC(X)O; R1 is C1-C8alkly, aryl-C1-C8alkyl, C1-C8haloalkyl or aryl; n is 0, 1, 2 or 3; X is O or S; and R2 is hydrogen, C1-C4alkyl or C1-C4haloalkyl, in which process, in a solvent, (1) an aniline derivative of formula (IV) wherein R is as defined above, and R3 is C1-C5alkyl or C1-C5haloalkyl, is diazotised in the presence of a mineral acid to form the corresponding diazonium salt of formul (II) wherein R and R3 are as defined above, Am− is an anion, and m is 1 or 2, (2) the resulting diazonium salt of formula (II) is carbonylated in the presence of a catalyst, CO and optionally a buffer, to form a benzoic acid derivative of formula (III) wherein R and R3 are as defined above, and (3) the benzoic acid derivative of formula (III) is then subjected to benzylic lactonisation in the ortho-position alkyl chain R3 in the presence of a free-radical initiator and a halogenating agent.
制备式(I)化合物的方法,其中R为卤素,R1O1R1S(O)n或(R1)2NC(X)O; R1为C1-C8烷基,芳基-C1-C8烷基,C1-C8卤代烷基或芳基; n为0、1、2或3; X为O或S; R2为氢、C1-C4烷基或C1-C4卤代烷基。在溶剂中,进行以下步骤:(1)在矿酸存在下,将式(IV)中的苯胺衍生物(其中R如上所述,R3为C1-C5烷基或C1-C5卤代烷基)重氮化,形成相应的重氮盐,其式为(II),其中R和R3如上所述,Am−为阴离子,m为1或2;(2)在催化剂、CO和可选的缓冲剂的存在下,将得到的式(II)的重氮盐羰基化,形成式(III)的苯甲酸衍生物,其中R和R3如上所述;(3)在自由基引发剂和卤化试剂的存在下,对式(III)的苯甲酸衍生物进行苯基内酯化反应,使其在正交位置的烷基链R3上发生。