Process for production of piperidine derivatives

1. A process of preparing a piperidine derivative compound of the formula I or II:

wherein

n is 0 or 1;

R 1 is hydrogen or hydroxy;

R 2 is hydrogen;

or, when n is 0, R 1 and R 2 taken together form a second bond between the carbon atoms bearing R 1 and R 2 , provided that when n is 1, R 1 and R 2 are each hydrogen;

R 3 is —COOH or —COOR 4 ;

R 4 is an alkyl or aryl moiety;

A, B, and D are the substituents of their rings, each of which may be different or the same, and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents;

said process comprising:

providing a regioisomer of the following formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ; and

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety and

converting the regioisomer to the piperidine derivative compound of formula I or II with a piperidine compound of formula III

2. A process according to claim 1 , wherein said providing the regioisomer comprises:

acylating an α-α-disubstituted-methylbenzene derivative having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

with a compound having the formula:

wherein

X 2 is a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

under conditions effective to produce the regioisomer.

3. A process according to claim 2 further comprising:

reacting an α-α-diunsubstituted-methylbenzene derivative having the formula:

with a methylating agent under conditions effective to produce the α-α-disubstituted-methylbenzene derivative.

4. A process according to claim 1 , wherein said providing the regioisomer comprises:

reacting a 4-(α-α-disubstituted)-toluic acid derivative having the formula:

wherein

X 2 is hydrogen; a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

with a compound having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

under conditions effective to produce the regioisomer.

5. A process according to claim 4 , further comprising:

reacting a 4-(α-α-diunsubstituted)-toluic acid derivative having the formula:

with a methylating agent under conditions effective to produce the 4-(α-α-disubstituted)-toluic acid derivative.

6. A process according to claim 1 , wherein said providing the regioisomer comprises:

providing an α-α-diunsubstituted regioisomer precursor having the formula:

and

methylating the α-α-diunsubstituted regioisomer precursor under conditions effective to produce the regioisomer.

7. A process according to claim 6 , wherein said providing the α-α-diunsubstituted regioisomer precursor comprises:

acylating an α-α-diunsubstituted-methylbenzene derivative having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

with a compound having the formula:

wherein

X 2 is a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

under conditions effective to produce the α-α-diunsubstituted regioisomer precursor.

8. A process according to claim 6 , wherein said providing the α-α-diunsubstituted regioisomer precursor comprises:

reacting a 4-(α-α-diunsubstituted)-toluic acid derivative having the formula:

wherein

X 2 is hydrogen; a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

with a compound having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

under conditions effective to produce the α-α-diunsubstituted regioisomer precursor.

9. A process according to claim 1 , further comprising:

reducing the piperidine derivative compound of formula I under conditions effective to form the piperidine derivative compound of formula II:

10. A process according to claim 9 , wherein the piperidine derivative compound of formula II is:

11. A process according to claim 9 , wherein the piperidine derivative compound of formula II is:

12. A process according to claim 1 , wherein the piperidine derivative compound of formula I is:

13. A process according to claim 1 , wherein the piperidine derivative compound of formula I is:

14. A process according to claim 1 , wherein said converting comprises:

halogenating the regioisomer of the formula:

under conditions effective to form a first intermediate compound of the formula:

wherein X 3 is a halogen or a hydroxy, alkoxy, or aryloxy moiety.

15. A process according to claim 14 , wherein said halogenating comprises sequentially:

decyclizing the regioisomer to produce an oxobutyl derivative having the formula:

and then

converting the oxobutyl derivative to the first intermediate compound.

16. A process according to claim 14 , wherein said converting further comprises:

reacting the first intermediate compound with the piperidine compound of formula III:

under conditions effective to form a piperidine derivative compound of formula IV:

17. A process according to claim 14 , wherein said converting further comprises:

esterifying the first intermediate compound to the ester thereof, having the formula:

and

reacting the ester with the piperidine compound of formula III:

under conditions effective to form a piperidine derivative compound of formula V:

18. A process according to claim 17 , further comprising:

hydrolyzing the piperidine derivative compound of formula V:

to the piperidine derivative compound of formula IV:

19. A process according to claim 14 , wherein n is 1 and wherein said converting further comprises:

reacting the first intermediate compound with 4-hydroxypiperidine under conditions effective to produce an N-substituted hydroxypiperidine having the formula:

and

reacting the N-substituted hydroxypiperidine with a diarylhalomethane having the formula:

wherein X 4 is a halogen

under conditions effective to form a piperidine compound derivative of formula VI:

20. A process according to claim 1 , wherein said converting comprises:

decyclizing the regioisomer of the formula:

under conditions effective to form an oxobutyl derivative of the formula:

wherein X 3 is a halogen or a hydroxy, alkoxy, or aryloxy moiety.

21. A process according to claim 20 , wherein said converting further comprises:

reacting the oxobutyl derivative with the piperidine compound of formula III:

under conditions effective to form the piperidine derivative precursor of the formula:

22. A process according to claim 21 , further comprising

converting the piperidine derivative precursor to the piperidine derivative compound of formula IV:

23. A process according to claim 21 , further comprising

reducing the piperidine derivative precursor under conditions effective to form a hydroxylated piperidine derivative precursor of the formula:

24. A process according to claim 23 , further comprising

converting the hydroxylated piperidine derivative precursor to a piperidine derivative compound of formula VII:

25. A process according to claim 20 , wherein n is 1 and wherein said converting further comprises:

reacting the oxobutyl derivative with 4-hydroxypiperidine under conditions effective to produce an N-substituted-hydroxypiperidine having the formula:

and

reacting the N-substituted hydroxypiperidine with a diarylhalomethane having the formula:

wherein X 4 is a halogen

under conditions effective to form the piperidine derivative precursor of the formula:

26. A process according to claim 25 , further comprising

converting the piperidine derivative precursor to the piperidine derivative compound of formula IV:

27. A process according to claim 25 , further comprising

reducing the piperidine derivative precursor under conditions effective to form a hydroxylated piperidine derivative precursor of the formula:

28. A process according to claim 27 , further comprising

converting the hydroxylated piperidine derivative precursor to the piperidine derivative compound of formula VIII:

29. A regioisomer having the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety; and

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents.

30. A process of preparing a regioisomer of the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety; and

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents,

said process comprising

acylating an α-α-disubstituted-methylbenzene derivative having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

with a compound having the formula:

wherein

X 2 is a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

under conditions effective to produce the regioisomer.

31. A process according to claim 30 further comprising:

reacting an α-α-diunsubstituted-methylbenzene derivative having the formula:

with a methylating agent under conditions effective to produce the α-α-disubstituted-methylbenzene derivative.

32. A process of preparing a regioisomer of the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety; and

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents,

said process comprising:

reacting a 4-(α-α-disubstituted)-toluic acid derivative having the formula:

wherein

X 2 is hydrogen; a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

with a compound having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

under conditions effective to produce the regioisomer.

33. A process according to claim 32 further comprising:

reacting a 4-(α-α-diunsubstituted)-toluic acid derivative having the formula:

with a methylating agent under conditions effective to produce the 4-(α-α-disubstituted)-toluic acid derivative.

34. A process of preparing a regioisomer of the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety; and

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents,

said process comprising:

providing an α-α-diunsubstituted regioisomer precursor having the formula:

and

methylating the α-α-diunsubstituted regioisomer precursor under conditions effective to produce the regioisomer.

35. A process according to claim 34 , wherein said providing the α-α-diunsubstituted regioisomer precursor comprises:

acylating an α-α-diunsubstituted-methylbenzene derivative having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

with a compound having the formula:

wherein

X 2 is a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

under conditions effective to produce the α-α-diunsubstituted regioisomer precursor.

36. A process according to claim 35 , wherein said providing the α-α-diunsubstituted regioisomer precursor comprises:

acylating a 4-(α-α-diunsubstituted)-toluic acid derivative having the formula:

wherein

X 2 is a halogen; an alkali metal oxide; a moiety having the formula —OR 10 ; a moiety having the formula —SR 10 ; or an amine; and

R 10 is selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety

with a compound having the formula:

wherein

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions

under conditions effective to produce the α-α-diunsubstituted regioisomer precursor.

37. An α-α-disubstituted-methylbenzene derivative having the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety,

with a proviso that when G 1 , G 2 , and G 3 are OR 8 , R 8 is not an alkyl moiety;

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents; and

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions.

38. An α-α-diunsubstituted-methylbenzene derivative having the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety,

with a proviso that when G 1 , G 2 , and G 3 are OR 8 , R 8 is not an alkyl moiety;

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents; and

X 1 is a halogen, trialkyl or triaryl tin, trialkyl or triaryl borate, trialkyl silicon, alkylhalo silicon, a substituted sulfonic ester, or substituents useful in organometallic coupling reactions.

39. An oxobutyl derivative having the formula:

wherein

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety,

with a proviso that when G 1 , G 2 , and G 3 are OR 8 , R 8 is not an alkyl moiety;

A is the substituents of its ring, each of which may be different or the same and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents; and

X 3 is a halogen or a hydroxy, alkoxy, or aryloxy moiety.

40. A piperidine derivative precursor having the formulae:

wherein

n is 0 or 1;

R 1 is hydrogen or hydroxy;

R 2 is hydrogen;

or, when n is 0, R 1 and R 2 taken together form a second bond between the carbon atoms bearing R 1 and R 2 , provided that when n is 1, R 1 and R 2 are each hydrogen;

Z is -CG 1 G 2 G 3 ,

G 1 , G 2 , and G 3 are the same or different and are selected from the group consisting of OR 8 , SR 8 , and NR 8 R 9 ;

R 8 and R 9 are the same or different and are selected from the group consisting of hydrogen, an alkyl moiety, and an aryl moiety; and

A, B, and D are the substituents of their rings, each of which may be different or the same, and are selected from the group consisting of hydrogen, halogens, alkyl, hydroxy, alkoxy, and other substituents.