申请人:Hieronymi Antje
公开号:US20100217015A1
公开(公告)日:2010-08-26
A process is described for the preparation of substituted heteroaromatics of the general formula (I)
where
X is oxygen, sulphur or NR
5
where R
5
is hydrogen, C
1
-C
20
-alkyl or C
5
-C
6
-aryl and
R
4
is C
1
-C
20
-alkyl, C
5
-C
6
-aryl or heteroaryl,
R
1
, R
2
, R
3
is hydrogen, halogen, C
1
-C
20
-alkyl, C
5
-C
6
-aryl or heteroaryl, by reaction
A) of a halogenated heteroaromatic of the general formula (II)
where
X has the meaning given for formula (I) and
R
6
is bromine, iodine or chlorine and
R
1
, R
2
and R
3
have the meaning given for formula (I),
with a Grignard reagent of the general formula (III)
R
4
MgHal (III)
where
R
4
has the meaning given for formula (I) and
Hal is bromine, iodine or chlorine or
B) reaction of the halogenated heteroaromatics of the formula (II) with magnesium firstly to give a Grignard compound of the general formula (IIIa)
where
Hal is bromine, iodine or chlorine and
X and R
1
, R
2
and R
3
have the meaning given for formula (I),
and further reaction with a halogenated compound of the general formula (IV)
R
4
Hal (IV)
where
R
4
has the meaning given for formula (I) and
Hal is bromine, iodine or chlorine,
where the reactions A) or B) are in each case carried out in the presence of an Ni or Pd catalyst, characterized in that the process is carried out in the presence of cycloalkyl alkyl ether as solvent and optionally a further solvent.
Likewise described is the use of cycloalkyl alkyl ethers, in particular cyclopentyl methyl ether, in the Kumada reaction for the preparation of substituted heteroaromatics, in particular substituted thiophenes.
描述了一种制备通式(I)中的取代杂芳烃的过程,其中X是氧、硫或NR5,其中R5是氢、C1-C20-烷基或C5-C6-芳基,R4是C1-C20-烷基、C5-C6-芳基或杂芳基,R1、R2、R3是氢、卤素、C1-C20-烷基、C5-C6-芳基或杂芳基,通过以下反应实现:A)通式(II)的卤代杂芳烃与通式(III)的格氏试剂反应;B)将通式(II)的卤代杂芳烃首先与镁反应,形成通式(IIIa)的格氏化合物,然后再与通式(IV)的卤代化合物进一步反应。在每种情况下,反应A)或B)均在Ni或Pd催化剂存在下进行,其特点在于在环烷基烷基醚溶剂的存在下进行该过程,也可以使用其他溶剂。同时还描述了在Kumada反应中使用环烷基烷基醚,特别是环戊基甲醚,用于制备取代杂芳烃,特别是取代噻吩。