Organic compounds -- part of the class 532-570 series – Organic compounds – Cyclopentanohydrophenanthrene ring system containing
Patent
1995-05-26
1997-04-15
Prior, Kimberly J.
Organic compounds -- part of the class 532-570 series
Organic compounds
Cyclopentanohydrophenanthrene ring system containing
552614, 552618, 552627, 552629, 552625, C07J 7500
Patent
active
056211244
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/EP93/02905 filed Oct. 21, 1993.
Estrone derivatives are known initial compounds for the synthesis of many secondary products, such as, for example, 19-nor compounds. In this connection, it is often imperative to alkylate the hydroxyl groups.
This takes place usually with the known standard alkylating agents, such as especially dialkyl sulfates. Generally, high yields are achieved with these reagents under mild reaction conditions. But because of their good alkylation properties, they have definite carcinogenic, mutagenic and teratogenic effects even in the smallest concentrations. This potential necessitates an extremely careful working-up both of the synthetics and of the production additives to be disposed of.
Therefore, in shop and laboratory practice, there has been an urgent need for a process which makes possible the desired formation of ethers in high yields, but without the adverse toxic side effects.
From the literature, the use of carbonic acid esters is known, and the latter are reacted, for example, under phase transfer conditions or in the presence of phosphines or basic catalysts under more or less drastic conditions.
Thus, it is known from Tetrahydron, 1990, Vol. 46, pages 1839-1848 to use carbonic acid esters in the presence of pentaalkyl guanidines as catalysts.
High yields were achieved in this case for alkylation of amines, mercaptans and simple alcohols or phenols.
The etherification of estrone derivatives under the conditions described there results only in inadequate reactions, generally <90%.
It was therefore the object of this invention to find a process by which estrone derivatives can be reacted without also using toxicologically harmful reagents in high yields.
This object of the invention is achieved by a process for the alkylation of estrone derivatives, which is characterized in that in the first stage, a 5-20% by weight, preferably 8-15% by weight suspension of the estrone derivatives in dimethylformamide is produced and 1-5 mol, preferably 2-4 mol of carbonic acid diester per mol of OH groups to be alkylated as well as 1-10 mol %, preferably 3-7 mol % of a guanidine and/or of an alkyl guanidine, relative to the estrone derivative, is dissolved in it and in a second stage, the oxygen contained in the reaction mixture is substantially removed from it and in a third stage, the reaction temperature is adjusted by continuous heating to 100.degree.-200.degree. C. preferably 130.degree.-170.degree. C. and the reaction is performed within 3-36 hours under the system pressure being established.
Another object of the invention is characterized in that dimethyl carbonate, diethyl carbonate, di-n-propyl and di-i-propyl carbonate, di-prim-(sec-, tert-)butyl carbonate are also used as dialkyl carbonates.
Another object of the invention is characterized in that guanidines are used by themselves or with methyl, ethyl, n-propyl, i-propyl, prim-(sec-, tert-)butyl radicals as catalysts.
With the process according to the invention, it is possible to alkylate estrone derivatives of the type which generally consist mainly of compounds of general formula 1a ##STR1## and in addition compounds of general formula 1b ##STR2## and/or of general formula 1c ##STR3## in which R=--CH.sub.3, --C.sub.2 H.sub.5, R.sup.1 =HO-- OR O.dbd., R.sup.2 and R.sup.3, independently of one another, mean OH-- or R and n=1 or 2.
According to the invention, compounds of general formula 1a or their technical mixtures preferably are used, in which R=--CH.sub.3, R.sup.1 is the group O.dbd. and n=1.
These estrone derivatives are used in an amount of as 5-20% by weight, preferably 8-15% by weight in suspension in dimethylformamide.
As alkylation reagents, carbonic acid diesters of general formula (2) ##STR4## are used for this purpose, in which R.sup.2 and R.sup.3 can be straight-chain or branched hydrocarbon radicals with 1-10 C atoms, preferably 1-4 C atoms, optionally substituted cycloaliphatic, alicyclic, araliphatic hydrocarbon radicals with 5-10 C atoms, preferably 6-8 C atoms. According
REFERENCES:
Barcelo, et al, Tetrahedron, vol. 46(6), pp. 1839-1848, (1990).
Lissel, et al., Synthesis, vol. 5, pp. 372-383, (1986).
Hubl Dieter
Seilz Carsten
Prior Kimberly J.
Schering Aktiengesellschaft
LandOfFree
Process for the alkylation of estrone derivatives does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the alkylation of estrone derivatives, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the alkylation of estrone derivatives will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-362021