Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1996-07-03
1997-11-18
Dentz, Bernard
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D30792
Patent
active
056889763
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/EP94/03891 filed Nov. 24, 1994.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the production of 8.alpha.,12-oxido-13,14,15,16-tetranorlabdane and to the use of special alumino layer silicates for the production of 8.alpha.,12-oxido-13,14,15,16-tetranorlabdane.
2. Statement of Related Art
8.alpha.,12-oxido-13,14,15,16-tetranorlabdane, hereinafter referred to as Ambroxan.RTM. is a valuable ambergris fragrance which is present in ambergris, a metabolic secretion of the sperm whale (Ullmanns Encyklopladie der technischen Chemie, Vol. 20, page 283, Verlag Chemie Weinheim 1981). Ambroxan.RTM. can be synthesized from sclareol by oxidative side-chain degradation and subsequent reduction of the lactone formed (sclareolide) in accordance with U.S. Pat. No. 3,050,532. The conversion of sclareolide into the odorless 8.alpha.,12-dihydroxy-13,14,15,16-tetranorlabdane, hereinafter referred to in short as diol, is carried out by methods known per se, for example by reduction with lithium aluminium hydride (Helv, Chim. Acta. 1950, 33, 1310), with sodium borohydride (Chem. Abstr. 57, 7316a) or with potassium borohydride/lithium chloride mixtures (Chem. Abstr. 94, 15913q).
The cyclizing dehydration of the diol to form Ambroxan.RTM. can be carried out with acidic catalysts, for example p-toluene sulfonic acid, p-toluene sulfonic acid chloride, catalytic quantities of sulfuric acid and acidic ion exchangers in various solvents, for example toluene, hexane, pyridine, tetrahydrofuran or methanol, preferably at boiling temperature.
U.S. Pat. No. 3,029,255 describes the use of p-naphthalene sulfonic acid or alumina as dehydration catalysts in the production of Ambroxan.RTM.. Besides resinification products and olefins, other secondary products are obtained in this that the yield of Ambroxan.RTM. is less than 77%.
JP-A-86/33184 (Takasago) describes a process for the production of Ambroxan.RTM. in which cyclization of the diol precursor is induced by special catalysts. The catalysts in question are acid-charged active bleaching earth, alumina or silica. The acids mentioned include, in particular, sulfuric acid, phosphoric acid and polyphosphoric acid. However, the Takasago process has disadvantages in regard to formation of iso isomers of Ambroxan.RTM..
The above-mentioned disadvantages of the Takasago process are obviated by the process described by applicants in earlier application WO 90/12793. However, the process according to WO 90/12793 requires relatively high reaction temperatures and relatively large quantities of catalyst. In addition, the special HCl-charged catalyst cannot readily be reused.
DESCRIPTION OF THE INVENTION
The problem addressed by the present invention was to develop a process for the production of Ambroxan.RTM. cyclizing dehydration of the diol precursor which would avoid the disadvantages of the processes known from the prior art.
It has surprisingly been found that Ambroxan.RTM. can be produced in high yields and purity if the diol precursor is subjected to cyclizing dehydration in a solvent and in the presence of alumino layer silicates which have an acid charge of 100 to 300 mval/100 g.
The expression "acid charge" in the context of the present invention applies to that part of the total acid content of the alumino layer silicates which is only loosely bound to the solid and which can be analytically determined by titration after elution with water. It is pointed out in this connection that the K catalysts have an additional acid content which is ionically bound to the skeleton of the catalyst and which does not dissociate off in aqueous dispersion.
The present invention relates to a process for the production of 8.alpha.,12-oxido-13,14,15,16-tetranorlabdane by dehydration of 8.alpha.,12-dihydroxy-13,14,15,16-tetranorlabdane (diol), in which 8.alpha.,12-dihydroxy-13,14,15,16-tetranorlabdane is subjected to cyclizing dehydration in a solvent in the presence of alumino layer silicates with an acid charge of 100 to 300 m
REFERENCES:
patent: 3029255 (1962-04-01), Stoll
patent: 3050532 (1962-08-01), Schumacher et al.
patent: 5274134 (1993-12-01), Bruns et al.
patent: 5470989 (1995-11-01), Gerke
Chem. Abs 105, No. 15, Oct 13, 1986, Columbus, Ohio.
Ullmanns Encyklopadie der technischen Chemie, vol. 20, p. 283, Verlag Chemie Weinheim 1981.
Helv, Chim. Acta. 1950, 33, 1310-1312.
Chem. Abstr. 57, 7316a (1962).
Chem. Abstr. 94, 15913q (1981).
Nachr. Chem. Tech. Lab 1985 (33), No. 3, p. 202.
Bomhard Andreas
Knuebel Georg
Markert Thomas
Schaper Ulf-Armin
Stalberg Theo
Dentz Bernard
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Millson Jr. Henry E.
Szoke Ernest G.
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