Process for preparing chlorinated biphenylanilides and biphenylanilines

Abstract

The present invention relates to a process for preparing substituted biphenylanilides of the formula (I). ##STR00001##

Claims

1. A process for preparing a halogenated biphenylanilide of formula (I) ##STR00022## in which X is selected from the group consisting of hydrogen, fluorine and chlorine; R.sup.1 is selected from the group consisting of NH(CO)R.sup.3, NCR.sup.4R.sup.5, NO.sub.2, NH.sub.2 and NHR.sup.3; R.sup.2 is chlorine; R.sup.3, R.sup.4, R.sup.5 are each independently selected from the group consisting of hydrogen, CH.sub.2(CO)CH.sub.3, C.sub.1-C.sub.8-alkyl, C.sub.1-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkynyl and C.sub.6-C.sub.18-aryl; or R.sup.4, R.sup.5, together with the carbon atom to which they are bonded, may form a 5- or 6-membered ring containing 1, 2 or 3 heteroatoms selected from N, O and S; n is selected from 1, 2 and 3, by reacting a compound of the formula (II) ##STR00023## in which Hal is selected from the group consisting of bromine and iodine; and R.sup.1 and X are each as defined above, in the presence of a base and a palladium catalyst selected from the group consisting of: a) a complex consisting of palladium in the 0 oxidation state and a phosphine ligand of the formula (V) or a salt thereof, b) a palladium salt in the presence of a phosphine ligand of the formula (V) or a salt thereof and c) metallic palladium, optionally applied to a support, in the presence of a phosphine ligand of the formula (V) or a salt thereof, where the phosphine ligand of the formula (V) is defined as follows: ##STR00024## wherein R.sup.6 is selected from the group consisting of hydrogen, C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 haloalkyl, phenyl, and NR.sup.7.sub.2 and R.sup.7 is a C.sub.1-C.sub.4 alkyl, or a salt thereof, wherein the phosphine ligand of formula (V) is di(tert-butyl)phenylphosphine, di-tert-butyl-p-[4-(trifluoromethyl)phenyl]phosphine, 4-(di-tert-butylphosphino)-p-N,N-dimethylaniline or di-tert-butyl-p-(4-methylphenyl)phosphine, or a salt thereof, in a solvent, with an organoboron compound of the formula (III) ##STR00025## selected from the group consisting of: (i) boronic acids of the formula (III) in which m is 2, p is 1, Q.sup.1 and Q.sup.2 are each hydroxyl groups, R.sup.2 and n are each as defined above, or the anhydrides, dimers or trimers formed from the boronic acids of the formula (III); (ii) boronic acid derivatives of the formula (III) in which m is 2, p is 1, Q.sup.1 and Q.sup.2 are each independently selected from the group consisting of F, Cl, Br, I, C.sub.1-4-alkyl-, C.sub.6-10-aryl-, C.sub.1-4-alkoxy- and C.sub.6-10-aryloxy, R.sup.2 and n are each as defined above; (iii) borinic acids of the formula (III) in which m is 1, p is 2, Q is selected from the group consisting of OH, F, Cl, Br, I, C.sub.1-4-alkyl, C.sub.6-10-aryl, C.sub.1-4-alkoxy and C.sub.6-10-aryloxy radicals, R.sup.2 and n are each as defined above; (iv) cyclic boronic esters of the formula (III) in which m is 2, p is 1, Q.sup.1 and Q.sup.2 are each independently a C.sub.1-4-alkoxy radical, which, R.sup.2 and n are each as defined above; (v) boronates of the formula (III) in which m is 3, p is 1, R.sup.2 and n are each as defined above, Q.sup.1 to Q.sup.3 are each independently selected from the group consisting of OH, F, Cl, Br, I, C.sub.1-4-alkyl, C.sub.6-10-aryl, C.sub.1-4-alkoxy and C.sub.6-10-aryloxy radicals, and in which the negative charge of the boronate anion is compensated for by a cation; (vi) triarylboranes of the formula (III) in which m is 0, p is 3, R.sup.2 and n are each as defined above; and (vii) tetraarylborates of the formula (III) in which m is 0, p is 4, R.sup.2 and n are each as defined above, and in which the negative charge of the boronate anion is compensated for by a cation.

2. The process according to claim 1, wherein the compound (II) is selected from the group consisting of N-(2-bromo-4-fluorophenyl)acetamide, N-(2-bromophenyl)acetamide, N-(2-bromophenyl)-3-oxobutanamide, N-(2-bromo-4-fluorophenyl)-3-oxobutanamide, 2-bromo-N-(propan-2-ylidene)aniline, 2-bromo-4-fluoro-N-(propan-2-ylidene)aniline, 2-bromo-4-fluoroaniline, and 2-bromoaniline.

3. The process according to claim 1, wherein the compound of the formula (III) is selected from the group consisting of bis(3,4-dichlorophenyl)borinic acid, bis(2,3-dichlorophenyl)borinic acid, bis(3-chlorophenyl)borinic acid, bis(4-chlorophenyl)borinic acid, 4-chlorophenylboronic acid, 3-chlorophenylboronic acid, 2-chlorophenylboronic acid, 3,4-dichlorophenylboronic acid and 2,3-dichlorophenylboronic acid.

4. The process according to claim 1 wherein the base is selected from the group consisting of alkali metal hydroxides, alkali metal carbonates and alkali metal hydrogencarbonates.

5. The process according to claim 1, wherein the palladium catalyst used is palladium catalyst a).

6. The process according to claim 1, wherein a palladium catalyst b) is used.

7. The process according to claim 1, wherein a palladium catalyst c) is used, and this palladium catalyst c) comprises or consists of metallic palladium on activated carbon in the presence of a phosphine ligand of formula (V) or a salt thereof.

8. The process according to claim 6, wherein the salt of the palladium catalyst b) is used and is selected from the group consisting of palladium chloride, palladium acetate, palladium acetylacetonate and bis(acetonitrile)palladium chloride.

9. The process according to claim 1, wherein a palladium catalyst b) is used, where the molar ratio of the palladium salt to the phosphine ligand of formula (V) or a salt thereof is 1:1 to 1:5.

10. The process according to claim 1, wherein 0.001 to 1.0 mol % of the palladium catalyst is used, based on the amount of the compound of the formula (II).

11. The process according to claim 1, wherein the reaction is conducted at a temperature of 20 C. to 100 C.

12. The process according to any claim 1, wherein the reaction is conducted in a mixture of water and an organic solvent.

13. The process according to claim 1, wherein the organoboron compound is (i).

14. The process according to claim 1, wherein the organoboron compound is (ii).

15. The process according to claim 1, wherein the organoboron compound is (iii).

16. The process according to claim 1, wherein the organoboron compound is (iv).

17. The process according to claim 1, wherein the organoboron compound is (v).

18. The process according to claim 1, wherein the organoboron compound is (vi).

19. The process according to claim 1, wherein the organoboron compound is (vii).

Description

EXAMPLE

Preparation of N-(3,4-dichloro-5-fluorobiphenyl-2-yl)acetamide

(1) Under argon, a mixture of N-(2-bromo-4-fluorophenyl)acetamide (1.00 g, 4.27 mmol), bis(3,4-dichlorophenyl)borinic acid (0.685 g, 2.14 mmol), potassium carbonate (1.03 g, 7.44 mmol), [(t-Bu).sub.2PhPH]BF.sub.4 (1.6 mg, 5.2 mol), Pd(acac).sub.2 (1.6 mg, 5.3 mol) was heated to 60 C. in 8 ml of water and 2 ml of 1-butanol. The reaction mixture was stirred at 60 C. for about 13 hours, cooled to room temperature and acidified with 1 N hydrochloric acid. After extracting the reaction mixture twice with ethyl acetate, the combined organic phases were dried over magnesium sulphate. The solvent was distilled off under reduced pressure. 1.21 g of crude product were obtained (90.8 area % HPLC, 86% yield).