Process for preparing aminocyclohexyl ether compounds

1. A process for preparing compounds of Formula I:

where Y is selected from 3,4-dimethoxyphenyl, 3,4-dihydroxyphenyl or a 3,4-dihalophenyl, comprising the steps of:

a) Mixing a cyclohexyl amine (iv)

 with a malic acid derivative (v)

 where R 2 is selected from hydrogen, esters, carbonates, carbamates, silyl ethers, phosphates or sulfates and where X and Z are independently selected from OH, C 1 -C 6 alkoxy, esters, halides or O-acyl, said X and Z may ontionally be ioined to form a ring (v-a)

to obtain a hydroxy succinimide (vi)

b) isolating the hydroxy succinimide (vi) to provide an isolated hydroxy succinimide (vi); and

c) reducing the isolated hydroxy succinimide (vi) to obtain a compound of Formula I.

2. The process of claim 1 comprising the steps of:

a) mixing an alkoxy ketone (iii)

 where Y is selected from 3,4-dimethoxyphenyl, 3,4-dihydroxyphenyl or a 3 , 4 -dihalophenyl, with a co-factor, a transaminase polypeptide and an amine to produce a cyclohexyl amine (iv)

b) mixing the cyclohexyl amine (iv) with a malic acid derivative (v)

where R 2 is selected from hydrogen, esters, carbonates, carbamates, silyl ethers, phosphates or sulfates, and where X and Z are independently selected from OH, C 1 -C 6 alkoxy, esters, halides or O-acyl, said X and Z may optionally be joined to form a ring (v-a)

to obtain a hydroxy succinimide (vi)

and

c) reducing the isolated hydroxy succinimide (vi) to obtain a compound of Formula I.

3. The process of claim 1 comprising the steps of:

a) mixing a substituted cycloalkanone (i)

 where R 1 is an activated leaving group and integer n is selected from 1, 2, or 3

b) with a substituted ethanol (ii)

 where Y is selected from 3,4-dimethoxyphenyl, 3,4-dihydroxyphenyl or a 3,4-dihalophenyl, in the presence of a metal salt and an organic base to form a cycloalkanone of structure

 where when n is 1 the cycloalkanone is ring expanded and when n is 3 the cycloalkanone is ring contacted, to provide an alkoxy ketone (iii)

c) mixing the alkoxy ketone (iii) with a co-factor, a transaminase polypeptide and an amine to produce a cyclohexyl amine (iv)

d) mixing the cyclohexyl amine (iv) with a malic acid derivative (v)

where R 2 is selected from hydrogen, esters, carbonates, carbamates, silyl ethers, phosphates or sulfates, and where X and Z are independently selected from OH, C1-C6 alkoxy, esters, halides or O-acyl, said X and Z may optionally be ioined to form a ring (v-a)

to obtain a hydroxy succinimide (vi)

and

e) reducing the isolated hydroxy succinimide (vi) to obtain a compound of Formula I.

4. The process of claim 3 which further comprises in step b) mixing the alkoxy ketone (iii) with the co-factor, and a slurry containing the transaminase polypeptide in a basic buffer and an amine.

5. The process of claim 4 , which further comprises adding an acid activator to step c.

6. The process of claim 5 , which further comprises adding a metal hydride to the hydroxy succinimide (vi) to obtain a compound of Formula I.

7. The process of claim 1 , comprising the steps of:

a) Mixing a substituted ethanol (ii)

 where Y is selected from 3,4-dimethoxyphenyl, 3,4-dihydroxyphenyl or a 3,4-dihalophenyl, with a zinc salt, a secondary amine and an organic base in a first solvent;

b) Adding a solution of a substituted cycloalkanone (i)

 where R 1 is an activated leaving group and integer n is 2, to obtain a mixture;

c) Heating the mixture to about 60 to about 150° C. and then cooling the mixture to less than about 60° C.;

d) Adding an acidic aqueous solution to create a biphasic mixture and discarding the aqueous phase;

e) Adding a second solvent to obtain an alkoxy ketone (iii)

f) Mixing a co-factor with a slurry of a transaminase polypeptide in a basic buffer and a primary amine to produce a solution;

g) Adding the alkoxy ketone (iii) in a second solvent to the solution of step f);

h) Adding a third solvent to create a biphasic mixture and discarding the aqueous layer;

i) Washing the organic layer from step h) with a basic aqueous solution and discarding the aqueous layer;

j) Performing a solvent switch from the third solvent to a fourth solvent;

k) Adding an acid to create a slurry;

l) Filtering the slurry to obtain cyclohexyl amine salt (iv-a);

m) Adding the cyclohexyl amine salt (iv-a) to a mixture of a first solvent and a basic aqueous solution and discarding the aqueous layer;

n) Adding a malic acid derivative, which is selected from malic acid or (v-a)

 in a first solvent to the cyclohexyl amine (iv-a) in a first solvent;

o) Adding an acid activator;

p) Adding a fourth solvent to obtain hydroxy succinimide (vi)

q) Mixing a metal hydride, an additive and an acid, which is selected from a Lewis acid or a protic acid, with a solution of the isolated hydroxy succinimide (vi);

r) Adding a fifth solvent and a basic aqueous solution to obtain a biphasic mixture and discarding the aqueous layer to obtain Compound A

 and

s) Adding an acid to obtain the salt of Compound A.

8. The process of claim 1 , where a transaminase polypeptide having an amino acid sequence of SEQ ID NO: 18 or SEQ ID NO: 206 is used.

9. The process of claim 1 , where a transaminase polypeptide having a polynucleotide sequence of SEQ ID NO: 17 or SEQ ID NO: 205 is used.

10. The process of claim 1 , comprising the steps of:

a) Mixing 3,4-dimethoxyphenyl ethanol with zinc chloride, diisopropylethylamine and pyrrolidine in toluene;

b) Adding 2-chlorocyclohexanone to obtain a mixture;

c) Adding aqueous hydrochloric acid and discarding the aqueous layer to obtain 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone;

d) Adding PLP to a slurry of a transaminase polypeptide having SEQ ID NO: 18 or SEQ ID NO: 206, in sodium tetraborate and isopropylamine to produce a solution;

e) Mixing 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone with the solution of step d);

f) Adding a mixture of IPA and MTBE to create a biphasic mixture and discarding the aqueous layer;

g) Performing a solvent switch on the organic layer from the mixture of IPA and MTBE to a fourth solvent, which is selected from sec-butanol or isopropanol, to obtain a solution;

h) Adding a solution of maleic acid in a fourth solvent to the solution of step g) to obtain 2-(3,4-dimethoxyphenylethoxy)-cyclohexylammonium maleate;

i) Mixing 2-(3,4-dimethoxyphenylethoxy)-cyclohexylammonium maleate with a first solvent and a basic aqueous solution and discarding the aqueous layer to obtain 2-(3,4-dimethoxyphenylethoxy)-cyclohexylamine;

j) Adding R-acetoxy malic acid anhydride to 2-(3,4-dimethoxyphenylethoxy)-cyclohexylamine;

k) Adding acetyl chloride;

1 ) Adding the fourth solvent, which is selected from ethanol or isopropanol, to obtain 1 -{2-[2-(3,4-dimethoxyphenyl)-ethoxy]-cyclohexyl}-3-hydroxypyrrolidine-2,5-dione;

m) Mixing 1-{2-[2-(3,4-dimethoxyphenyl)-ethoxy]-cyclohexyl}-3-hydroxypyrrolidine-2,5-dione with sodium borohydride, trimethylborate and an acid, which is selected from BF 3 OEt 2 or BF 3 THF, in THF;

n) Adding water;

o) Adding a basic aqueous solution, which is selected from sodium hydroxide or ammonia, and IPAc, to obtain a biphasic mixture and discarding the aqueous layer to obtain

 and

p) Adding hydrochloric acid to obtain the salt of Compound A.

11. The process of claim 10 , which further comprises in step e), mixing 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone in a second solvent, which is selected from DMSO, ethanol or isopropanol, with the solution of step d).

12. The process of claim 1 , comprising the steps of:

a) Mixing a substituted ethanol (ii)

 where Y is selected from 3,4-dimethoxyphenyl, 3,4-dihydroxyphenyl or a 3,4-dihalophenyl, with a zinc salt, a secondary amine and an organic base in a first solvent;

b) Adding a solution of a substituted cycloalkanone (i)

 where R 1 is an activated leaving group and integer n is 2, to obtain a mixture;

c) Adding an acidic aqueous solution and discarding the aqueous phase to obtain an alkoxy ketone (iii)

d) Mixing a co-factor with a slurry of a transaminase polypeptide in a basic buffer and a primary amine to produce a solution;

e) Adding the alkoxy ketone (iii) in a second solvent to the solution of step d);

f) Adding a third solvent to create a biphasic mixture and discarding the aqueous layer;

g) Washing the organic layer from step f) with a basic aqueous solution and discarding the aqueous layer;

h) Performing a solvent switch from the third solvent to a fourth solvent;

i) Adding D-malic acid in a fourth solvent to obtain cyclohexyl amine D-malate salt (iv-c)

j) Mixing the cyclohexyl amine D-malate salt (iv-c) with a sixth solvent and adding a catalytic amount of an acid activator;

k) Adding HMDS and a Lewis acid to obtain hydroxy succinimide (vi)

l) Mixing a metal hydride, an additive and an acid, which is selected from a Lewis acid or a protic acid, with a solution of the isolated hydroxy succinimide (vi);

m) Adding a fifth solvent and a basic aqueous solution to obtain a biphasic mixture and discarding the aqueous layer to obtain Compound A

 and

n) Adding an acid to obtain the salt of Compound A.

13. The process of claim 12 , where the cyclohexyl amine D-malate salt (iv-c)

is isolated as the crystalline form.

14. The process of claim 12 , where a transaminase polypeptide having an amino acid sequence of SEQ ID NO: 18 or SEQ ID NO: 206 is used.

15. The process of claim 12 , comprising the steps of:

a) Mixing 3,4-dimethoxyphenyl ethanol with zinc chloride, diisopropylethylamine and pyrrolidine in toluene;

b) Adding 2-chlorocyclohexanone to obtain a mixture;

c) Adding aqueous hydrochloric acid and discarding the aqueous layer to obtain 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone;

d) Adding PLP to a slurry of a transaminase polypeptide having SEQ ID NO: 206, in sodium tetraborate and isopropylamine to produce a solution;

e) Mixing 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone with the solution of step d);

f) Adding a mixture of IPA and MTBE to create a biphasic mixture and discarding the aqueous layer;

g) Performing a solvent switch on the organic layer from the mixture of IPA and MTBE to a fourth solvent, which is selected from sec-butanol or isopropanol, to obtain a solution;

h) Adding a solution of D-malic acid in a fourth solvent to the solution of step g) to obtain 2-(3,4-dimethoxyphenylethoxy)-cyclohexylammonium malate;

i) Mixing 2-(3,4-dimethoxyphenylethoxy)-cyclohexylammonium malate with an ester solvent and adding a catalytic amount of an alkyl boronic acid;

j) Heating to about 90 to about 125° C., then cooling to about 70° C.;

k) Adding HMDS and a Lewis acid to obtain 1-{2-[2-(3,4-dimethoxyphenyl)-ethoxy]-cyclohexyl}-3-hydroxypyrrolidine-2,5-dione, where said Lewis acid is zinc chloride, iron(II) chloride, lithium chloride, copper(II) trifluoromethanesulfonate, iron(III) chloride, iron(II) bromide, zinc bromide, zinc acetate or zinc trifluoromethanesulfonate;

l) Mixing 1-{2-[2-(3,4-dimethoxyphenyl)-ethoxy]-cyclohexyl}-3-hydroxypyrrolidine-2,5-dione with sodium borohydride, trimethylborate and an acid, which is selected from BF 3 OEt 2 or BF 3 THF, in THF;

m) Adding water;

n) Adding a basic aqueous solution, which is selected from sodium hydroxide or ammonia, and IPAc, to obtain a biphasic mixture and discarding the aqueous layer to obtain

 and

o) Adding hydrochloric acid to obtain the salt of Compound A.

16. The process of claim 15 , where the alkyl boronic acid is methyl boronic acid or butyl boronic acid.

17. The process of claim 15 , where the Lewis acid in step k) is zinc chloride.

18. The process of claim 1 comprising the steps of:

a) Mixing 3,4-dimethoxyphenyl ethanol with zinc chloride, diisopropylethylamine and pyrrolidine in toluene;

b) Adding 2-chlorocyclohexanone to obtain a mixture;

c) Adding aqueous hydrochloric acid and discarding the aqueous layer to obtain 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone;

d) Adding PLP to a slurry of a transaminase polypeptide, said transaminase polypeptide having SEQ ID NO: 18 or SEQ ID NO: 206, in sodium tetraborate and isopropylamine to produce a solution;

e) Mixing 2-(3,4-dimethoxyphenyl ethoxy)-cyclohexanone with the solution of step d);

f) Adding a mixture of IPA and MTBE to create a biphasic mixture and discarding the aqueous layer;

g) Performing a solvent switch on the organic layer from the mixture of IPA and MTBE to a fourth solvent, which is selected from sec-butanol or isopropanol, to obtain a solution;

h) Adding a solution of oxalic acid in the fourth solvent, which is selected from sec-butanol or isopropanol, to the solution of step g to obtain 2-(3,4-dimethoxyphenylethoxy)-cyclohexylammonium oxalate iv-b;

i) Adding 2-(3,4-dimethoxyphenylethoxy)-cyclohexylammonium oxalate iv-b to a mixture of DMAc and potassium bicarbonate followed by (R)-1,4-dibromo-butan-2-ol;

j) Adding IPAc and a basic aqueous solution to obtain a biphasic mixture and discarding the aqueous layer to obtain

 and

k) Adding hydrochloric acid to obtain the salt of Compound A.