PROCESS FOR PREPARING 3-METHYLCYCLOPENTADECANE-1,5-DIOL

Abstract

The present invention relates to a process for preparing 3-methylcyclopentadecane-1,5-diol (I) by hydrogenolysis of 14-methyl-16,17,18-trioxatricyclo[10.3.2.1]octadecane (II). The invention further relates to a process for preparing 3-methylcyclopentadecane-1,5-diol is a macrocyclic diol that can serve as precursor for a macrocyclic odorant, such as muscone and muscenone.

##STR00001##

Claims

1.-14. (canceled)

15. A process for preparing a diol of formula (I) ##STR00008## which comprises hydrogenolysis of an ozonide of formula (II) ##STR00009## in the presence of a base and a catalyst comprising molybdenum-doped Raney nickel.

16. The process of claim 15, wherein hydrogenolysis is carried out at a hydrogen pressure of 5 MPa or less and at a temperature of 120 C. or less.

17. The process of claim 15, wherein the molybdenum-doped Raney nickel is used in an amount of at least 8 wt-% relative to the mass of the ozonide of formula (II).

18. The process of claim 15, wherein hydrogenolysis is performed in the absence of a liquid organic solvent or diluent.

19. The process of claim 15, wherein hydrogenolysis is carried out with the ozonide of formula (II) being dispersed in a liquid phase comprising the base, an organic solvent selected from C.sub.1-C.sub.4-alkanols, and optionally water.

20. The process of claim 19, wherein the ozonide of formula (II) is used in an amount of from 2 to 200 g/l relative to the solvent.

21. The process of claim 15, wherein the base is selected from alkali metal hydroxides.

22. The process of claim 15, wherein the concentration of the base is in the range of from 5 mM to 50 mM.

23. The process of claim 15, wherein hydrogenolysis is carried out at temperatures in the range of from 50 C. to 120 C., and at hydrogen pressures of from 1 to 5 MPa.

24. The process of claim 15, wherein the conditions for hydrogenolysis are applied over a period of for up to 36 h.

25. The process of claim 15, wherein hydrogenolysis is carried out continuously or batchwise.

26. The process of claim 15, further comprising the preparation of the ozonide of formula (II) by ozonization of a compound of formula (III) ##STR00010##

27. The process of claim 15, wherein the molybdenum-doped Raney nickel contains aluminum and from 75 to 95 wt-% nickel and from 0.5 to 2.0 wt-% molybdenum based on the total mass of the molybdenum-doped Raney nickel.

28. A process for preparing a macrocyclic odorant of the formulae (V) or (VI) comprising the steps of: (i) preparing a diol of formula (I) ##STR00011## by carrying out the process of claim 15; (ii) dehydrogenating and dehydrating the diol of formula (I) so as to form an enol-ether of formula (IV) ##STR00012## and (iii) treating the enol-ether of formula (IV) with an acidic agent so as to form a compound of formula (V) ##STR00013## and optionally the step of (iv) hydrogenating the compound of formula (V) so as to form a compound of formula (VI) ##STR00014##

29. The process of claim 15, wherein hydrogenolysis is carried out with the ozonide of formula (II) being dispersed in a liquid phase comprising the base, an organic solvent selected from the group consisting of methanol, ethanol or isopropanol, and mixtures thereof, and optionally water.

30. The process of claim 19, wherein the ozonide of formula (II) is used in an amount of from 10 to 50 g/l relative to the solvent.

31. The process of claim 15, wherein the base is selected from the group consisting of NaOH and KOH.

32. The process of claim 15, wherein hydrogenolysis is carried out at temperatures in the range of from 55 C. to 110 C., and at hydrogen pressures of from 1.5 to 4 MPa.

33. The process of claim 15, wherein the conditions for hydrogenolysis are applied over a period of 2 to 36 h.

Description

EXAMPLES

I) Gas Chromatographic Analysis

Gas Chromatography (GC) System and Separation Method:

[0037] GC-system: Agilent 7890 Series A;

[0038] GC-Column: DB-WAX (30 m (Length), 0.32 mm (ID), 0.25 m (Film));

[0039] Injector at 230 C., detector at 280 C. and flow 1.5 ml.

[0040] Temperature program: 80 C. to 250 C. in 3 C./min, 250 C. for 15 min.

[0041] The yields of the exemplary syntheses described below which are expressed in wt-% were determined by GC.

II) Comparative Example 1

[0042] 2 g 14-Methyl-16,17,18-trioxatricyclo[10.3.2.1]octadecane (80-90% purity determined by NMR) were dispersed at 25 C. in 100 ml methanol. To this mixture, 0.5 ml 10 wt-% NaOH in water and 0.5 g Raney Nickel (2400 Raney Nickel, CAS 7440-02-0) were added. In a 300 ml autoclave, the mixture was heated to a temperature of 70 C. and at this temperature the system was pressurized with 2 MPa hydrogen. The system was allowed to react under these conditions for 18 h. After this time, the autoclave was cooled down to room temperature and the Raney nickel was removed by filtration. The solvent was evaporated and the product was extracted with ethyl acetate so as to obtain 1.6 g of a crude product which contained 43 wt-% 3-methylcyclopentadecane-1,5-dione representing a yield of 45% based on the initial amount of 14-methyl-16,17,18-trioxatricyclo[10.3.2.1]octadecane. Only traces of 3-methylcyclopentadecane-1,5-diol were detected (<10 wt-% as determined by GC).

[0043] The Raney Nickel used as a catalyst in example 1 (2400 Raney Nickel) is a powder having a mass-averaged particle size d(0.5) in the range of 25-55 m that is provided as a slurry in water with a mass ratio of dry catalyst and water of 50:50. In example 1, 2400 Raney Nickel was used in the form of the slurry precipitate (mass ratio of dry catalyst and water of 75:25). Analysis of the composition of 2400 Raney Nickel resulted in the detection of 75 wt-% Ni and 2.2 wt-% Fe, and 2.1 wt-% chromium (Cr) relative to the total (dry) mass of 2400 Raney Nickel. For said analysis a sample of 2400 Raney Nickel was dried overnight at 105 C. under argon. In addition of Ni, Fe and Cr, 2400 Raney Nickel contains aluminum.

III) Example 2

[0044] 2 g 14-Methyl-16,17,18-trioxatricyclo[10.3.2.1]octadecane (80-90% purity determined by NMR) were dispersed at 25 C. in 100 ml of methanol. To this mixture, 0.5 ml 10 wt-% NaOH in water and 0.5 g molybdenum-doped Raney Nickel were added. In a 300 ml autoclave, the mixture was heated to a temperature of 70 C. and at this temperature the system was pressurized with 2 MPa hydrogen. The system was allowed to react under these conditions for 18 h. After this time, the autoclave was cooled down to room temperature and the Raney nickel was removed by filtration. The solvent was evaporated and the product was extracted with ethyl acetate so as to obtain 1.75 g of a crude product which contained 71 wt-% 3-methylcyclopentadecane-1,5-diol representing a yield of 80% based on the initial amount of 14-methyl-16,17,18-trioxatricyclo[10.3.2.1]octadecane.

[0045] The molybdenum-doped Raney Nickel used as a catalyst in the example 2 is a powder having a mass-averaged particle size d(0.5) of 33 m (d(0.1): 8 m; d(0.9): 101 m) that is provided as a slurry in water with a mass ratio of dry catalyst and water of 50:50. In example 2, the molybdenum-doped Raney Nickel was used in the form of the slurry precipitate (mass ratio of dry catalyst and water of 75:25). Analysis of the catalyst composition resulted in the detection of 80 wt-% Ni and 1.0 wt-% Mo relative to the total (dry) mass of the molybdenum-doped Raney Nickel. The contents of C, H and N were each <0.5 wt-% and the content of S was <0.01 wt-%. Said analysis was not performed under an inert atmosphere and does not take any NiO, which might have formed, into account. In addition of Ni and Mo, the catalyst contains aluminum.