A process for the preparation of a compound of general formula I:
1
wherein:
R
1
is hydrogen or C
1
-C
6
alkyl, C
2
-C
6
alkenyl or C
2
-C
6
alkynyl (any of which may optionally be substituted with one or more substituents selected from halogen and OH) or COOH, COH, COOR
4
, COR
6
,CONR
4
R
5
or CONHSO
2
R
4
;
R
4
and R
5
are each independently hydrogen or C
1
-C
4
alkyl optionally substituted with one or more halogen atoms;
R
6
is a halogen atom or a group R
4
;
R
2
is hydrogen or halo;
R
3
is C
1
-C
4
alkyl, C
2
-C
4
alkenyl or C
2
-C
4
alkynyl, any of which may optionally be substituted with one or more halogen atoms, or halo;
the process comprising reacting a compound of general formula II:
2
wherein R
1
, R
2
and R
3
are as defined for general formula I;
with a nitrating agent comprising nitric acid or a mixture of nitric and sulphuric acids in the presence of an organic solvent and in the presence of acetic anhydride, characterised in that the molar ratio of acetic anhydride to compound of general formula I is from about 1:1 to 3:1.
一种通式 I 化合物的制备工艺:
1
其中
R
1
是氢或 C
1
-C
6
烷基,C
2
-C
6
烯基或 C
2
-C
6
炔基(其中任何一个可任选被一个或多个选自卤素和 OH 的取代基取代)或 COOH、COH、COOR
4
、COR
6
、CONR
4
R
5
或 CONHSO
2
R
4
;
R
4
和 R
5
各自独立地为氢或 C
1
-C
4
烷基,可任选被一个或多个卤素原子取代;
R
6
是卤素原子或基团 R
4
;
R
2
是氢原子或卤原子;
R
3
是 C
1
-C
4
烷基、C
2
-C
4
烯基或 C
2
-C
4
炔基,其中任何一个可任选被一个或多个卤素原子或卤素取代;
该工艺包括使通式 II 的化合物发生反应:
2
其中 R
1
, R
2
和 R
3
如通式 I 所定义;
在有机溶剂和
醋酸酐存在下,用硝化剂(包括
硝酸或
硝酸和
硫酸的混合物)硝化,其特征在于
醋酸酐与通式 I 化合物的摩尔比约为 1:1 至 3:1。