PROCESS FOR PRODUCTION OF D-SORBITOL

Abstract

The present invention relates to a new process for the production of D-sorbitol.

Claims

1. Process for the production of the compound of formula (II) ##STR00005## wherein the compound of formula (I) ##STR00006## is hydrogenated in the presence of at least one transition metal-based complex.

2. A process according to claim 1, wherein the transition metal of the transition metal based complex is selected from the group consisting of Ru, Ir, Pd, Pt, Rh, Fe, Os, Ni, and Co.

3. A process according to claim 2, wherein the transition metal of the transition metal based complex is selected from the group consisting of Ru and Ir.

4. A process according to claim 1, wherein the transition metal based complex comprises at least one organic ligand.

5. A process according to claim 1, wherein the transition metal based complex is selected from the group consisting of the complexes of formulae (III)-(VIII) ##STR00007##

6. A process according to claim 1, wherein the process is carried out in at least one solvent.

7. A process according to claim 6, wherein the process is carried out in at least one non-aqueous, organic or polar solvent.

8. A process according to claim 1, wherein the process is carried out in the presence of H.sub.2 gas.

9. A process according to claim 1, wherein the process is carried out at a pressure of about 2 bar to about 200 bar, preferably of about 5 bar to about 100 bar, more preferably of about 10 bar to about 60 bar.

10. A process according to claim 1, which is carried out at a temperature in the range from about 20 C. to about 150 C., preferably from about 30 C. to about 100 C.

11. A process according to claim 1, which is carried out at a molar ratio of substrate to catalyst in the range of about 50 to about 100000, preferably of about 100 to about 40000, more preferably of about 5000 to about 30000.

12. A process according to claim 1, wherein the process is carried out in the presence of at least one base, preferably at least one alkoxide base.

Description

EXAMPLE 1: CONVERSION OF GLUCONOLACTONE TO SORBITOL UNDER VARIOUS Conditions

[0052] General Procedure for Hydrogenation:

[0053] All manipulations were done in a N.sub.2-filled glovebox, except for weighing of gluconolactone. In air, gluconolactone samples (1.0 mmol) were weighed into 5-mL crimp vials and transferred in N.sub.2-filled glovebox. Into these samples, KOMe solution in methanol (5 mol % wt gluconolactone) and catalyst solution/slurry in methanol (0.5 mol % wt gluconolactone, S/C 200) were added; volume is further diluted to 3.0 mL with methanol. These vials were capped with PTFE coated septum and placed inside a Premex 96er parallel hydrogenation reactor. The system was purged with N.sub.2 (310 bar) and H.sub.2 (310 bar). The reactions were carried out 50 bar H.sub.2, 70 C. 16 h with stirring (300 rpm). After the reaction, HPLC samples were prepared in deionized H.sub.2O. Concentrations of the gluconolactone and sorbitol in the reaction were determined using calibration curves.

[0054] Analysis:

[0055] Products were analyzed with HPLC using Agilent Technologies 1260 Infinity instrument equipped with Waters 2414 Refractive Index Detector. The parameters are column: BIORAD Aminez-HPX-87H, 3007.8 mm, column temperature: 50 C., flow rate: 0.55 mL/min, injection volume: 100 L, eluent: 5 mM H.sub.2SO.sub.4(aq), collection time: 60 min. Retention times, min: gluconolactone=9.6, sorbitol=10.9.

TABLE-US-00001 TABLE 1 Ru- and Ir-catalyst testing (Conditions: 1 mmol gluconolactone, 5 mol % KOMe, 0.5 mol % catalyst, 3 mL total volume methanol, 50 bar H.sub.2, 16 h, HPLC analysis in H.sub.2O, DF = 168; .sup.aat 70 C., .sup.bat 90 C.). Gluconolactone Sorbitol Conversion Catalyst [mM] [mM] [%] III.sup.a 8.9 379 98 IV.sup.a 194 165 46 V.sup.b 2.2 339 99 VI.sup.b 163 153 49 VII.sup.b 146 128 47 VIII.sup.b 178 136 43 None (Ref 1) 363 0 0

TABLE-US-00002 TABLE 2 Solvent testing using III as catalyst (Conditions: 1 mmol gluconolactone, 5 mol % KOMe, 0.5 mol % III, 3 mL total volume, 50 bar H.sub.2, at 70 C., 16 h, HPLC analysis in H.sub.2O, DF = 168). Gluconolactone Sorbitol Conversion Catalyst [mM] [mM] [%] Methanol 7.7 347 98 Ethanol 18.1 388 96 Isopropanol 58.7 262 82 Tetrahydrofuran 278 58.6 18

TABLE-US-00003 TABLE 3 Variation of the molar substrate-to-catalyst (S/C) ratio using III as catalyst (Conditions: 1 mmol gluconolactone, 5 mol % KOMe, 0.02-0.002 mol % III, 3 mL total volume methanol, 50 bar H.sub.2, 90 C., 16 h, HPLC analysis in H.sub.2O, DF = 168). Gluconolactone Sorbitol Conversion S/C [mM] [mM] [%] 5000 1.1 305 100 10000 1.7 290 99 20000 6.0 397 99 50000 68.8 183 73

TABLE-US-00004 TABLE 4 Variation of temperature and amount of base using III as catalyst (Conditions: 1 mmol gluconolactone, 1-5 mol % KOMe, 0.5 mol % III, 3 mL total volume methanol, 50 bar H.sub.2, 16 h, HPLC analysis in H.sub.2O, DF = 168). Gluconolactone Sorbitol Conversion Conditions [mM] [mM] [%] 5 mol % KOMe, 70 C. 8.9 379 98 1 mol % KOMe, 90 C. 5.7 378 99

EXAMPLE 2: CONVERSION OF GLUCONOLACTONE TO SORBITOL

[0056] In air, gluconolactone (10.0 mmol, 1.8 g) was weighed into a 120-mL high pressure stainless steel reactor (EM60-100-HC, Premex) and transferred in N.sub.2-filled glovebox. Into this, 10 mL methanol was added, followed by KOMe (5 mol % wt gluconolactone, 0.5 mmol, 0.035 g) solution in methanol (10 mL) and catalyst III (0.02 mol % wt gluconolactone, S/C 5000) solution/slurry in methanol (10 mL). The reactor was closed inside the glovebox. The autoclave was purged with N.sub.2 (520 bars) and H.sub.2 (510 bars). The reaction were carried out at 50 bar H.sub.2, 90 C. with stirring (1000 rpm). After the reaction, HPLC samples were prepared in deionized H.sub.2O. Concentrations of the gluconolactone and sorbitol in the reaction were determined using calibration curves. The solvent from the reaction mixture was removed in vacuo to obtained a crude yield of sorbitol (1.9 g) from the reaction. The analytical method used was the same as in Example 1 analysis showed 4.9 mM gluconolactone and 356 mM sorbitol (99% conversion).