Organic compounds -- part of the class 532-570 series – Organic compounds – Sulfonic acids or salts thereof
Patent
1995-03-10
1996-06-04
Dees, Jose G.
Organic compounds -- part of the class 532-570 series
Organic compounds
Sulfonic acids or salts thereof
540489, 548146, 548400, 546184, 546348, C07C30929
Patent
active
055234690
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION OF THE INVENTION
The present invention relates to the laevorotatory isomers of alkylammonium 1-(3-aminophenyl)ethanesulphonates of formula: ##STR1## in which R.sup.+ represents a tetraalkylammonium or trialkylphenylalkylammonium residue, to their preparation and their use as intermediates in the preparation of compounds which are useful as cholecystokinin (CCK) and gastrin antagonists.
In the preceding definitions, and in those which follow, the alkyl radicals contain 1 to 4 carbon atoms in a straight or branched chain. They preferably represent the n-butyl radical.
The compounds of formula (I) (laevorotatory isomers) can be prepared in accordance with the following process: (RS)-1-(1-bromoethyl)-3-nitrobenzene and, if necessary, conversion to the potassium salt to give potassium (RS)-1-(3-nitrophenyl)ethanesulphonate, and B forms of benzylquininium 1-(3-nitrophenyl)ethanesulphonate, separation of the A form and recovery of a mixture enriched in the B form, in b) into potassium 1-(3-nitrophenyl)ethanesulphonate, thereafter into phenylglycinol 1-(3-nitrophenyl)ethanesulphonate, B form, and finally into the tetraalkylammonium or trialkylphenylalkylammonium 1-(3-nitrophenyl)-ethanesulphonate (laevorotatory isomer) (I) (laevorotatory isomer).
It is particularly advantageous to carry out stage a) in aqueous solution at a temperature of between 50.degree. C. and 100.degree. C. and preferably at 80.degree. C.
The alkali metal sulphite is preferably sodium sulphite or potassium sulphite.
To recover the product, it is preferable to convert it to the tetraalkylammonium or trialkylphenylammonium salt, isolate this and then convert it to the potassium salt.
Stage b) is preferably carried out by means of an N-benzylquininium halide, and preferably the chloride, in the presence of potassium dihydrogenphosphate in an aqueous medium and at a temperature of between 10.degree. C. and 30.degree. C. in particular at a temperature of about 20.degree. C.
The potassium salt of stage c) is obtained by treatment with potassium nonafluorobutanesulphonate, in an inert solvent such as acetone, at a temperature of between 10.degree. C. and 30.degree. C., and preferably at 20.degree. C.
The phenylglycinol salt of stage c) is obtained by treatment with (R)-(-)-phenylglycinol in the presence of an acid such as hydrochloric acid, in an aqueous medium, at a temperature of between 10.degree. C. and 30.degree. C. and preferably at 20.degree. C.
The phenylglycinol salt is thereafter converted to the compound of formula (I) by means of a tetraalkylammonium or trialkylphenylalkylammonium salt, preferably the hydrogensulphates, in an aqueous medium, at a temperature of between 10.degree. C. and 30.degree. C. and preferably at 20.degree. C.
The reduction of stage d) is generally carried out under hydrogen pressure, in the presence of a hydrogenation catalyst such as palladium, in an inert solvent such as an alcohol (for example ethanol), at a temperature of about 25.degree. C. Preferably, a hydrogen pressure of 100 kPa is used.
The compounds of formula (I) (laevorotatory isomers) are particularly valuable as intermediates for the preparation of the enantiomers of the compounds of formula: ##STR2## and their salts.
In formula (II), A represents:
A) a --CH.sub.2 --CO--NR.sub.1 R.sub.2 residue, in which R.sub.1 represents one of the following radicals: (a) phenyl optionally substituted by one or more substituents chosen from among halogen atoms and alkyl, alkoxy, hydroxyl polyfluoroalkyl, nitro, alkylthio, alkoxycarbonyl, carboxyl, acylamino, methylenedioxy, polyfluoroalkoxy, trifluoromethylthio, phenoxy, phenyl, benzyl, phenylamino and CONR.sub.3 R.sub.4 radicals, which may be identical or different, represent a hydrogen atom or an alkyl, phenyl (optionally substituted by one or more substituents chosen from among halogen atoms and alkyl, alkoxy and alkylthio radicals), indanyl, cycloalkylalkyl, cycloalkyl or phenylalkyl radical or else R.sub.3 and R.sub.4 together with the nitrogen atom to which they are attached form a saturated or u
REFERENCES:
patent: 3883502 (1975-05-01), Sommer et al.
Conrad, III Joseph M.
Dees Jos,e G.
Rhone-Poulenc Rorer S.A.
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