Methods and intermediates for the preparation of bile acid derivatives

1. A method of preparing a compound of formula I

or a pharmaceutically acceptable salt, hydrate, solvate, or amino acid, sulfate or glucuronide conjugate, or prodrug thereof,

wherein:

R 1 is OH, alkoxy, or oxo;

R 2 is OH, OSO 3 H, OCOCH 3 , OPO 3 H 2 , halogen, or alkyl optionally substituted with one or more halogen;

R 3 is H; or R 2 and R 3 taken together with the carbon atom to which they are attached form a carbonyl;

R 5 is OH, OR 11 , OSO 3 H, OCOCH 3 , OPO 3 H 2 , halogen, or alkyl optionally substituted with one or more halogen;

R 6 is H; or R 5 and R 6 taken together with the carbon atom to which they are attached form a carbonyl;

R 4 is alkyl optionally substituted with one or more halogen or OH, alkenyl, or alkynyl;

R 7 is OH, OSO 3 H, SO 3 H, OSO 2 NH 2 , SO 2 NH 2 , OPO 3 H 2 , PO 3 H 2 , CO 2 H, C(O)NHOH, NH(CH 2 ) 2 SO 3 H, NHCH 2 CO 2 H or optionally substituted tetrazolyl, oxadiazolyl, thiadiazolyl, 5-oxo-1,2,4-oxadiazolyl, 5-oxo-1,2,4-thiadiazolyl, oxazolidine-dionyl, thiazolidine-dionyl, 3-hydroxyisoxazolyl, 3-hydroxyisothiazolyl, pyrimidine, 3,5-difluoro-4-hydroxyphenyl, or 2,4-difluoro-3-hydroxyphenyl;

R 8 , R 9 , and R 10 are each independently H, OH, halogen, or alkyl optionally substituted with one or more halogen or OH, or R 8 and R 9 taken together with the carbon atoms to which they are attached form a 3- to 6-membered carbocyclic or heterocyclic ring comprising 1 or 2 heteroatoms selected from N, O, and S, or R 9 and R 10 taken together with the carbon atoms to which they are attached form a 3- to 6-membered carbocyclic or heterocyclic ring comprising 1 or 2 heteroatoms selected from N, O, and S;

m is 0, 1, or 2;

n is 0 or 1; and

p is 0 or 1;

the method comprising the step of reacting a compound of formula I-4 with a halogenating reagent to provide a compound of formula I-5a

wherein X is —(CHR 8 ) m (CHR 9 ) n (CHR 10 ) p —R 7 , and R 7 , R 8 , R 9 , and R 10 may be protected by R 11 selected from acetyl, benzoyl, C(O)C 1 -C 4 alkyl, C 1 -C 6 alkoxycarbonyl, optionally substituted aryloxycarbonyl, benzyl, pivaloyl, tetrahydropyranyl ether, tetrahydrofuranyl, 2-methoxyethoxymethyl ether, methoxymethyl ether, ethoxyethyl ether, p-methoxybenzyl ether, methylthiomethyl ether, triphenylmethyl, dimethoxytrityl, methoxytrityl, and silyl ether.

2. The method of claim 1 , wherein the compound of formula I is a compound of formula I-9

or a pharmaceutically acceptable salt, hydrate, solvate, or amino acid, sulfate or glucuronide conjugate, or prodrug thereof.

3. The method of claim 1 , wherein the compound of formula I is a compound of formula II

or a pharmaceutically acceptable salt, hydrate, solvate, or amino acid, sulfate or glucuronide conjugate, or prodrug thereof.

4. The method of claim 1 , wherein the compound of formula I is a compound of formula III

or a pharmaceutically acceptable salt, hydrate, solvate, or amino acid, sulfate or glucuronide conjugate, or prodrug thereof.

5. The method of claim 1 , wherein the compound of formula I is compound 100

6. The method of claim 1 , wherein the halogenating agent is a brominating agent.

7. The method of claim 1 , wherein the halogenating reagent is an iodinating reagent.

8. The method of claim 1 , further comprising converting a compound of formula I-1 into the compound of formula I-4, comprising the steps of

1) protecting the compound of formula I-1 to provide compound of formula I-2;

2) forming a leaving group at C12 to provide a compound of formula I-3; and

3) eliminating the leaving group at C12 to provide the alkene compound of formula I-4

9. The method of claim 1 , further comprising converting the compound of formula I-5a into a compound of formula I-6a, comprising the step of

5) reacting the compound of formula I-5a with an oxidizing agent to prepare the compound of formula I-6a

10. The method of claim 9 , further comprising converting the compound of formula I-6a into a compound of formula I-7, comprising the step of

6) reacting the compound of formula I-6a with a reducing agent to prepare the compound of formula I-7

11. The method of claim 10 , further comprising converting the compound of formula I-7 into the compound of formula I, comprising the step of

8) reacting the compound of formula I-7 with a reducing agent to provide the compound of formula I.

12. The method of claim 2 , further comprising converting the compound of formula I-5a into the compound of formula I, wherein the compound of formula I-5a is a compound of formula I-5b and the compound of formula I is a compound of formula I-9, comprising the steps of:

1) reacting the compound of formula I-5b with a reducing agent to prepare the compound of formula I-5c

2) reacting the compound of formula I-5c with a reducing agent to provide the compound of formula I-5d

and deprotecting the compound of formula I-5d to provide the compound of formula I-9.

13. The method of claim 10 , further comprising converting the compound of formula I-7 into the compound of formula I, wherein the compound of formula I-7 is a compound of formula I-7a and the compound of formula I is a compound of formula I-9, comprising the steps of:

1) reacting the compound of formula I-7a with a reducing agent to provide a compound of formula I-8a; and

2) deprotecting the compound of formula I-8a to obtain the compound of formula I-9

14. The method of claim 6 , wherein the brominating agent is N-bromosuccinimide.

15. The method of claim 7 , wherein the iodinating agent is N-iodosuccinimide.

16. The method of claim 9 , wherein the oxidizing agent is RuCl 3 .

17. The method of claim 10 , wherein the reducing agent is zinc metal.

18. The method of claim 11 , wherein the reducing agent is sodium borohydride.

19. The method of claim 12 , wherein the compound of formula I-9 is compound 100

20. The method of claim 5 , further comprising converting the compound of formula I-5a into the compound of formula I, wherein the compound of formula I-5a is a compound of formula 21b and the compound of formula I is compound 100, comprising the steps of:

1) reacting the compound of formula 21b with a reducing agent to prepare a compound of formula 47b;

2) reacting the compound of formula 47b with a reducing agent to provide a compound of formula 49b; and

3) deprotecting the compound of formula 49b to provide compound 100

21. The method of claim 10 , further comprising converting the compound of formula I-7 to the compound formula I, wherein the compound of formula I-7 is a compound of formula C, and the compound of formula I is a compound of formula C2, comprising the steps of:

a) deprotecting the compound of formula C to prepare a compound of formula C1; and

b) reacting the compound of formula C1 with a reducing agent to prepare the compound of formula C2

22. The method of claim 21 , wherein the compound of formula C is compound 23a, the compound of formula C1 is compound 40, and the compound of formula C2 is compound 100