Production of chirally pure amino alcohol intermediates, derivatives thereof, and uses thereof
View Patent ↗A method of selectively preparing a chiral 2S-amino alcohol useful in preparation of an amide sulfonated or acylated with alkyl, substituted aryl or substituted heteroaryl is described. The method involves reacting a di-tert-butyl diazene-1,2-dicarboxylate with a (4S)-4-benzyl-3-[(S)-trifluoromethyl-alkyl substituted alkanoyl]-1,3-oxazolidin-2-one to afford a di-tert-butyl 1-(1S,2S)-([(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate. This dicarboxylate is then reduced to yield di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate. The resulting product is deblocked with an acid to yield the acid addition salt of (2S,3S)-trifluoro-hydrazino-methyl alkan-1-ol. The acid addition salt of (2S,3S)-trifluor-2-hydrazino-methyl alkan-1-ol is hydrogenated in the presence of a suitable metal catalyst to yield the amino alcohol (2S,3S)-2-amino-trifluoro-methyl alkan-1-ol HCl.
1. A method of selectively preparing a chiral amino alcohol useful in preparation of an amine sulfonated or acylated with a residue containing an alkyl, substituted aryl or substituted heteroaryl group, said method comprising the steps of:
(a) reacting di-tert-butyl azodicarboxylate with an anion derived from (4S)-4-benzyl-3-[(S)-trifluoromethyl-alkyl substituted alkanoyl]-1,3-oxazolidin-2-one to afford a di-tert-butyl 1-(1S,2S)-([(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate;
(b) reducing the di-tert-butyl 1-(1S,2S)-(1-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate of (a) to yield di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate;
(c) deblocking the product of (b) with an acid to yield the acid addition salt of (2S,3S)-trifluoro-hydrazino-methyl alkan-1-ol; and
(d) hydrogenating the acid addition salt of (2S,3S)-trifluor-2-hydrazino-methyl alkan-1-ol in the presence of suitable metal catalyst to yield the amino alcohol (2S,3S)-2-Amino-trifluoro-methyl alkan-1-ol HCl.
2. The method according to claim 1 , further comprising the step of triturating the product of (d) in a suitable solvent to remove trapped metal contaminants from the catalyst.
3. The method according to claim 1 , wherein the reacting step (a) is performed under cold conditions.
4. The method according to claim 1 , wherein the reacting step (a) further comprises reacting the (4S)-4-benzyl-3-[(S)-trifluoromethyl-alkyl substituted alkanoyl]-1,3-oxazolidin-2-one with lithium diisopropyl amide or potassium bis(trimethyl)silylamide in a suitable solvent system.
5. The method according to claim 4 , wherein the solvent comprises tetrahydrofuran.
6. The method according to claim 4 , wherein the reacting step (a) further comprises quenching the reaction with glacial acetic acid.
7. The method according to claim 1 , wherein the reduction step (b) is performed by reaction of dissolved di-tert-butyl 1-(1S,2S)-(1-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate and LiBH 4 in tetrahydrofuran and water or t-butyl methyl ether and water.
8. The method according to claim 1 , wherein the deblocking step (c) comprises mixing di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate and HCl.
9. The method according to claim 8 , wherein concentrated HCl is added to the di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate at 30° C. to 50° C.
10. The method according to claim 1 , wherein the catalyst in the hydrogenating step is selected from the group consisting of PtO 2 , PdO 2 , and RaNi.
11. The method according to claim 1 , wherein the reacting step comprises:
reacting di-tert-butyl azodicarboxylate with a the anion derived from (4S)-4-benzyl-3-[(3S)-4,4,4-trifluoro-3-methylbutanoyl]-1,3-oxazolidin-2-one to afford a di-tert-butyl 1-((1S,2S)-1-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-3,3,3-trifluoro-2-methylpropyl)hydrazine-1,2-dicarboxylate.
12. The method according to claim 11 , wherein the reducing step comprises:
reducing the di-tert-butyl 1-((1S,2S)-1-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-3,3,3-trifluoro-2-methylpropyl)hydrazine-1,2-dicarboxylate of (a) to yield di-tert-butyl 1-[(1S,2S)-3,3,3-trifluoro-1-(hydroxymethyl)-2-methylpropyl]hydrazine-1,2-dicarboxylate.
13. The method according to claim 1 , wherein the deblocking step comprises deblocking the product of (b) with an acid to yield the acid addition salt of (2S,3S)-4,4,4-trifluoro-2-hydrazino-3-methyl-butan-1-ol.
14. The method according to claim 1 , wherein the hydrogenating step comprises
hydrogenating the acid addition salt of (2S,3S)-4,4,4-trifluoro-2-hydrazino-3 -methyl-butan-1-ol in the presence of suitable metal catalyst to yield the amino alcohol (2S,3S)-2-Amino-4,4,4-trifluoro3-methyl-butan-1-ol HCl.
15. A method of selectively preparing a chiral 1S, 2S, aryl or heterocyclic sulfonamide, said method comprising the steps of:
(a) reacting a di-tert-butyl diazene-1,2-dicarboxylate with a (4S)-4-benzyl-3-[(S)-trifluoromethyl-alkyl substituted alkanoyl]-1,3-oxazolidin-2-one to afford a di-tert-butyl 1-(1S,2S)-([(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate;
(b) reducing the di-tert-butyl 1-(1S,2S)-(1-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidine-3-yl]-carbonyl}-trifluoromethyl-alkyl substituted alkyl)hydrazine-1,2-dicarboxylate of (a) to yield di-tert-butyl 1-(1S,2S)-[trifluoromethyl-alkyl substituted alkyl]hydrazine-1-(hydroxymethyl)-1,2-dicarboxylate;
(c) deblocking the product of (b) with an acid to yield the acid addition salt of (2S,3S)-trifluoro-hydrazino-methyl alkan-1-ol;
(d) hydrogenating the acid addition salt of (2S,3S)-trifluor-2-hydrazino-methyl alkan-1-ol in the presence of suitable metal catalyst to yield the amino alcohol (2S,3S)-2-Amino-trifluoro methyl alkan-1-ol HCl;
(e) triturating the product of (d) in a suitable solvent to remove trapped metal contaminants from the catalyst; and
(f) reacting the amino alcohol or salt thereof with a heterocyclic or aryl-substituted sulfonyl chloride.
16. The method according to claim 15 wherein the reacting step (e) further comprises mixing the amino alcohol or salt thereof with a suitable solvent and a tertiary base.
17. The method according to claim 15 , wherein the method further comprises the steps of protecting the amino alcohol by silylation prior to reacting (f) and, following reacting (f), deblocking to yield 5-halo-N-[(1S,2S)-3,3,3-trifluoro-1-(hydroxymethyl)-2-methylpropyl]thiophene-2-sulfonamide.
18. The method according to claim 15 , wherein the heterocyclic sulfonyl chloride is a 5-halo thiophene sulfonyl chloride.
19. The method according to claim 18 wherein the 5-halo-thiophene-sulfonyl chloride is 5-chloro-thiophene-2-sulfonyl chloride.
20. The method according to claim 19 , wherein the 5-halo-thiophenesulfonyl chloride is dissolved in dichloromethane.