Method of preparing glucosylceramide synthase inhibitors

Abstract

The invention relates to a method of preparing inhibitors of glucosylceramide synthase (GCS) useful for the treatment metabolic diseases, such as lysosomal storage diseases, either alone or in combination with enzyme replacement therapy, and for the treatment of cancer.

Claims

1. A method of preparing the compound of Formula VIII ##STR00049## comprising reacting a compound of Formula X ##STR00050## with quinuclidinol.

2. The method according to claim 1 further including reacting the compound of Formula XI ##STR00051## with imidazole to form the compound of Formula IX ##STR00052##

3. The method according to claim 1 further including heating to reflux the compound of Formula XI ##STR00053## to form the compound of Formula X ##STR00054##

4. The method according to claim 1 further including reacting, while heating to reflux, the compound of Formula XI ##STR00055## with imidazole to form the compounds of Formula IX and Formula X ##STR00056##

5. The method according to claim 4, further including reacting the compound of Formula XII ##STR00057## with N,N-carbonyldiimidazole to form the compound of Formula XI ##STR00058##

6. The method according to claim 5, further including reacting the compound of Formula XIII ##STR00059## with N,N-carbonyldiimidazole and hydroxylamine to form the compound of Formula XII ##STR00060##

7. The method according to claim 6, further including reacting the compound of Formula XIV ##STR00061## with potassium tert-butoxide and methyl iodide followed by reacting the ethyl ester so formed with lithium hydroxide to form the compound of Formula XIII.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) ##STR00041##

(2) In reaction 1 of Scheme 1, the carboxylic acid compound of Formula VII is converted to the corresponding hydroxamic acid compound of Formula VI by reacting VII with N,N-carbonyldiimidazole (i.e. CDI) in a polar aprotic solvent, such as tetrahydrofuran (THF). The solution is stirred at a temperature between about 5 C. to about 25 C., preferable about 20 C., for a time period between about 5 minutes to about 30 minutes, preferably about 10 to 15 minutes. The resulting solution mixture is allowed to warm to room temperature and stirred for an additional time period between about 30 minutes to about 2 hours, preferably about 1 hour. Hydroxylamine is then added to the solution mixture at a temperature between about 5 C. to about 10 C., preferable about 3 C. The resulting reaction mixture is stirred under inert atmosphere (i.e., nitrogen) for a time period between about 5 min to about 8 hours, preferably about 10 min.

(3) In reaction 2 of Scheme 1, the hydroxamic acid compound of Formula VI is converted to the corresponding compound of Formula V by the addition of N,N-carbonyldiimidazole to a solution of VI in toluene under inert atmosphere (i.e., nitrogen) and stirred for a time period between about 30 minutes to about 4 hours, preferably about 2.5 hours.

(4) In reaction 3 of Scheme 1, the compound of Formula V is converted to the corresponding compounds of Formula II and Formula IV by reacting V with imidazole in the presence of a aprotic solvent, such as toluene. The reaction mixture is heated to reflux for a time period between about 4 hours to about 28 hours, preferable about 6 hours.

(5) In reaction 4 of Scheme 1, a mixture of the compounds of Formula II and Formula IV (or each intermediate separately) is converted to the corresponding compound of Formula I by reacting II and IV with (S)-(+)-quinuclidinol in the presence of a aprotic solvent, such as toluene. The reaction mixture is heated to reflux for a time period between about 12 hours to about 24 hours, preferable about 18 hours.

Preparation A

(6) To 4-Fluorophenylthioamide (50.35 g, 1 eq.) was added 8.6 weight volumes of 200 proof ethanol (based on thioamide) (430 mL) and ethyl 4-chloroacetoacetate (68.2 g, 1.1 eq.). The mixture was place under a nitrogen atmosphere. It was heated under reflux for 5 h and allowed to cool to room temperature. The solution was concentrated to an oil and TBME (10 volumes, 500 mL) and 6 volumes of saturated NaHCO3 (300 mL) added. The aqueous layer was back extracted with 5 volumes (250 mL) of TBME. The combined organic layer was washed with water and then concentrated to an oil and then dried to a solid. The product was crystallized from 3 weight volumes of hot hexanes. Yield 89% Product 98.7% pure by HPLC (area %).

Example 1

(S)-Quinuclidin-3-yl (2-(2-(4-fluorophenyl)thiazol-4-yl)propan-2-yl)carbamate

(7) Step 1: Dimethylation with Methyl Iodide

(8) ##STR00042##

(9) Procedure:

(10) In a 100 L reactor was added tetrahydrofuran (THF, 28.4 Kg) and potassium tert-butoxide (MW 112.21, 2.28 Kg g, 4.0 equiv.). This mixture was cooled to 0-2 C. (internal temperature). The starting ester (MW 265.3, 2.0 Kg, 1.0 equiv.) was dissolved in THF (4 L) and transferred to the reactor over a period of 10-60 min, keeping the internal temperature below 10 C. during the addition. The reaction mixture was stirred at 3-9 C. for 15-60 min. A solution of methyl iodide (MW 141.94, 1.88 L, 4.0 equiv.) in THF (4.8 L) was added to the reactor over 30-120 min keeping the internal temperature below 10 C. A solution of NaCl (2.0 Kg) in water (14 L) was added over 10 min and the mixture was stirred for at least 10 min more. The reaction was made acidic by the addition of 1 M HCl (1.44 L). The layers were separated and the aqueous layer was back extracted with THF (6.2 kg). The combined organic layers were vacuum distilled to 16 l. This THF solution of the Step1 product was used in the next reaction.

(11) Step 2: Hydrolysis of the Ethyl Ester with LiOH Monohydrate

(12) ##STR00043##

(13) Procedure:

(14) To the ester in THF was added a solution of LiOH.H.sub.2O (MW 41.96, 0.695 Kg, 2.2 equiv.) in water (9.3 L) was added. The mixture was heated at reflux for 8-16 hours. After the reactions was judge complete by HPLC, water (12 L) was added and the mixture was vacuum distilled to 16 L. TBME (5.9 kg) was added and after stirring the layers were separated. The aqueous layer containing the product was washed a second time with TBME (5.9 Kg). TBME was added to the aqueous layer and the mixture was made acidic (pH3) by the addition of 5 M HCl (3.67 Kg). The layers were separated and the aqueous layer was extracted a second time with TBME (4.5 Kg). Heptane (15 Kg) was added to the combined organic layers and the mixture was vacuum distilled to 16 L. After heating and cooling to 5-25 C. and stirring for at least 3 h, the product was filtered, washed with heptane, and vacuum dried. Yield 85.8% (2.15 Kg) HPLC purity (area %) 99.72%

(15) Reaction 1: Formation of Hydroxamic Acid with NH.sub.2OH

(16) ##STR00044##

(17) Procedure:

(18) To a 100 L reactor was added THF (14.2 Kg) and N,N-carbonyldiimidazole (CDI; MW 162.15, 1.34 Kg, 1.1 equiv.). The acid from reaction 2 (2.0 Kg, 1.0 equiv) dissolved in THF (4 L) was added over 15-20 min. The mixture was stirred at room temperature for 2.5-3 h. The reaction was cooled to 0-3 C. Aqueous hydroxylamine (50% aqueous; 1.7 L, 4.0 equiv.) was added over 5-15 min keeping the internal temperature less than 18 C. After the addition was complete, the layers were separated and the organic layer was washed with water (12 Kg) and a solution of sodium chloride (2.0 Kg) in water (12 L). The separated organic layer was vacuum distill to 16 l. Toluene (13.8 Kg) was added and the mixture was again vacuum distilled to 16 L. Heptane (11 kg) was added and the mixture was stirred at room temperature for at least 16 h. The resulting solid was filtered, washed with heptane (11 Kg) and vacuum dried at room temperature. The yield was 1.58 Kg (74.8%).

(19) Reaction 2: Conversion of Hydroxamic Acid to a Dioxazolone

(20) ##STR00045##

(21) Procedure:

(22) Toluene (17.3 Kg) and the hydroxamic acid from, reaction 1 (MW 280.32, 2.0 Kg) was transferred to a 100 L reactor. After stirring at room temperature for at least 15 min carbonyl diimidazole CDI (MW 162.15, 1.27 Kg, 1.1 equiv.) was added. The mixture was stirred at room temperature for 1-4 h until the reaction was judge complete by HPLC.

(23) Reaction 3 Conversion of the Dioxazolone to a Mixture of the Imidazole Urea and Isocyanate

(24) ##STR00046##

(25) Procedure:

(26) The solution of the dioxazolone (reaction 2) was heated at 60 C. for 6-16 hours to complete the conversion to a mixture of the isocyanate and imidazole urea as judge by HPLC analysis.

(27) Reaction 4: Final Conversion to the Carbamate

(28) ##STR00047##

(29) Procedure:

(30) (S)-(+)-3-quinuclidinol (1.14 Kg, 1.18 equiv.) was added to the mixture of the isocyanate and imidazole urea toluene solution (reaction 3) and the solution was heated at 100-110 C. for 18-28 h. Toluene (8.6 Kg) was added to the reaction and the mixture was washed twice with water (20 Kg). The product was removed from the organic layer with two extractions of aqueous 1M HCl. (19.7 Kg). Isopropyl acetate (34.8 Kg) was added to the combined acidic aqueous layers. The mixture was cooled to 5-10 C. and 10M aqueous NaOH (5.3 Kg) was added. The layers were separated and the organic layer was vacuum distilled to 16 L. Heptane (21.4 Kg) was added to the remaining isopropyl acetate solution and again the solution was distilled to 16 L. the resulting suspension was stirred for at least 4 h. The product was filtered, washed with heptane (13.7 Kg) and vacuum dried at room temperature. The yield was 2.3 Kg (82.8% yield). HPLC purity (Area %) 99.7%.

(31) .sup.1H NMR (400 MHz, CDCl.sub.3) 8.04-7.83 (m, 2H), 7.20-6.99 (m, 3H), 5.53 (s, 1H), 4.73-4.55 (m, 1H), 3.18 (dd, J=14.5, 8.4 Hz, 1H), 3.05-2.19 (m, 5H), 2.0-1.76 (m, 11H). .sup.13C NMR (100 MHz, CDCl.sub.3) 166.38, 165.02, 162.54, 162.8-155.0 (d, CF), 130.06, 128.43, 128.34, 116.01, 115.79, 112.46, 71.18, 55.70, 54.13, 47.42, 46.52, 27.94, 25.41, 24.67, 19.58.

Example 2

(S)-Quinuclidin-3-yl (2-(2-(4-fluorophenyl)thiazol-4-yl)propan-2-yl)carbamate

(32) ##STR00048##
2-(2-(4-fluorophenyl)thiazol-4-yl)-2-methylpropanoic acid (1 g) and diisopropylethyl amine (0.57 ml) were dissolved in toluene and stirred at 110 C. under N2. DPPA (0.9 ml) was added dropwise. The mixture was stirred for 3 hours at 110 C. to complete the conversion of the acetyl azide and isocyanate. Quinuclidin-3-ol (0.72 g) was added and stirred for 18 hours. The result mixture was diluted with toluene (50 ml) and washed with saturated sodium bicarbonate solution. The organic layer was concentrated to oil. Product of quinuclidin-3-yl (2-(2-(4-fluorophenyl)thiazol-4-yl)propan-2-yl)carbamate was purified by crystallization from EtOAc (0.6 g).