申请人:Rack Michael
公开号:US20110245505A1
公开(公告)日:2011-10-06
A process for manufacturing a 5-formyl-pyridine-2,3-dicarboxylic acid ester (I) wherein Z is hydrogen or halogen; Z
1
is hydrogen, halogen, cyano or nitro and R
1
, R
2
are independently C
1
-C
10
-alkyl, comprising the steps of (i) reacting a compound of formula (II), wherein the symbols are as in formula (I), with a nitrosation agent (III) R
3
—O—N═O (III) wherein R
3
is C
1
-C
8
-alkyl, in the presence of an alkali metal or alkaline earth metal alcoholates or carbonates in a polar aprotic solvent at a temperature of from −45 to 40° C., to obtain an oxime compound (IV) where Z, Z
1
, R
1
and R
2
are as in formula (I), and (ii) reacting oxime compound (IV) with an aliphatic C
1
-C
10
-aldehyde in the presence of a Lewis acid at a temperature in the range of from 0 to 100° C. The compounds of formula (I) are useful intermediates in the synthesis of herbicidal imidazolinones, like imazamox.
一种制造5-甲酰基吡啶-2,3-二羧酸酯(I)的过程,其中Z为氢或卤素; Z1为氢,卤素,氰或硝基,R1,R2独立地为C1-C10烷基,包括以下步骤:(i)在极性无水溶剂中,在-45至40℃的温度下,将式(II)的化合物与亚硝酰化试剂(III)R3-O-N═O(III)反应,其中符号如式(I)中所示,存在碱金属或碱土金属醇盐或碳酸盐,以获得肟化合物(IV),其中Z,Z1,R1和R2如式(I)中所示,(ii)在0至100℃的温度下,在路易斯酸的存在下,将肟化合物(IV)与脂肪族C1-C10醛反应。式(I)的化合物是合成除草剂咪唑烷酮(如咪唑草胺)的有用中间体。