Title of Invention

"PROCESS FOR THE SYNTHESIS OF ARYLOXYPROPYLAMINE AND HETEROARYLOXYPROPYLAMINE COMPOUNDS"

Abstract The present invention relates to a process for the synthesis of aryloxypropylamine and heteroaryloxypropylamine of formula I: (I) where: A is aryl or heteroaryl, where the aryl is preferably a phenyl, optionally substituted, selected from benzyl and tolyl and the heteroaryl is preferably thiophenyl; Y is an aryl, preferably phenyl, a substituted phenyl or a naphthyl, where the substituted phenyl is preferably selected from tolyl, trihalomethyltolyl and alkoxytolyl, starting from a suitable amino alcohol of formula II: QH 9 (II)
Full Text Process for the synthesis of aryloxypropylamine and heteroaryloxypropylamine
Description
The present invention is related to a process for the synthesis of aryloxypropylamine and heteroaryloxypropylamine of formula I:
(I)
where:
A is aryl or heteroaryl, where aryl is preferably a phenyl, optionally substituted, selected from benzyl and tolyl and the heteroaryl is preferably thiophenyl; Y is an aryl, preferably phenyl, a substituted phenyl or a naphthyl, where the substituted phenyl is preferably selected from tolyl, trihalomethyltolyl and alkoxytolyl; starting from a suitable amino alcohol of formula II:


A
9


(II)
in which the hydroxyl is substituted with a halogen to give Compounds of formula III, which are obtained as hydro-halogenated salts:
OH
N H
A
N H
HX



(II)
(III)
The Compounds of formula III are reacted with a protective agent of amino groups to give Compounds of formula IV
N H
1 G
HX



(IV)
where G indicates a protector group of the amino group, of formula R-C(=0)-, where R is an alkyl, optionally substituted, residue, aryl or alkoxy residue, or of formula R'-S(=0)2- where R' indicates a alkyl residue optionally substituted or aryl residue.
(III)
The Compounds of formula IV are reacted with the anions of the aryl alcohols of interest, preferably phenols, substituted phenols or naphthols to give the Compounds of formula V

(IV) (V)
The Compounds of formula V are then appropriately deprotected. PRIOR ART
Aryloxypropylamines are an important class of pharmaceutical products used in
the care of attention-deficit disorder and hyperactivity disturbances.
Some of the most important products belonging to this class are the following:
O'
H
(VI)
Fluoxetine - formula VI
(VII)
Atomoxetine -formula VII O. O'
N' H
Nisoxetine - formula VIII
Duloxetine is a chemically very similar product having the following formula:
It is used as drug for the care of depression and incontinence.
The known synthesis paths for obtaining this product type starting from the
corresponding amino alcohol can be divided into two groups:
A) Aromatic nucleophilic substitution processes like those described in
W02000290239.
This kind of process provides for the substitution of a halogen atom on the ring by the OH of the amino alcohol of formula II, suitably activated as an alcoholate. This process type is applicable with good results only when electron-attractor groups are present on the aromatic ring which bears the halogen to be substituted (in the diagram below, when A and X have the meanings defmed above and Y' is an electron-attractor group).
OH
(II) (X) (XI)
B) Nucleophilic substitution reactions of the hydroxyl of the amino alcohol. (see for example US4018895 and US4314081).
This kind of process normally provides for the following reaction sequence: a) protection of the amino group;

b) activation of the hydroxyl by means of its transformation into a good leavingt group (preferably a halogen);
c) nucleophilic substitution with the appropriate aryloxy, optionally substituted;
QH
G
d) deprotection of the amino group
QH
N H


(IV)
(II)
(XII)


G
(XIII)
The processes of this type are longer but have a much wider ränge of application. DESCRIPTION OF THE INVENTION
Düring the study of the synthesis of aryloxy and heteroaryloxy propylamine we surprisingly found that if in the processes of B type the order of the amino group protection and hydroxyl activation stages is reversed, greater overall yields are obtained. Moreover, taking into consideration that the activation of the hydroxyl is generally carried out in an acidic environment, reversing the two reaction stages permits using protective groups of the amino group which are not compatible with acidic environments.
The reaction sequence of the present invention is therefore the following: a) activation of the hydroxyl of an amino alcohol of formula II by means of its substitution with a halogen atom, preferably by means of reaction with a suitable halogenating agent (for example of the type SOX2, PX3, POX3, etc., where X

indicates a halogen), to obtain the salified amino halogen-derivative of formula III.
A y A y
(II) (III)
This reaction is carried out in a halogenated solvent, preferably methylene Chloride, at a temperature in the ränge of 0 °C - 40 °C, preferably in the ränge of 20 °C - 25 °C. The quantity of halogenating agent, preferably thionyl chloride, is in the ränge of 0.8 - 3 equivalents with respect to the starting amino alcohol, preferably in the ränge of 1 - 2 equivalents. The reaction time is in the ränge of 1 - 4 hours, preferably in the ränge of 1 - 2 hours.
b) protection of the amino group of the amino halogen-derivative of formula III, to obtain the protected amino halogen-derivative of formula IV.
G
(III) (IV)
where G is an amino protecting group.
The methods for protecting amines are well known in the art and are described for example in Greene et al., Protective Croups in Organic Synthesis, chapter 7, Third Edition, 1999, Wiley-Interscience, pages 494-653, incorporated here for reference.
HX
Preferably, G indicates a protector group of the amino group, preferably of formula R-C(=0)- where R is an alkyl residue, ptionally substituted, aryl or alkoxy residue, or of formula R'-S(==0)2- where R' indicates an alkyl, optionally substituted, alkyl residue or aryl residue.

The protection reaction is carried out in a halogenated solvent, preferably methylene chloride, and water, (in ratios in the ränge of 0.5 - 1.5 to 1, preferably 0.75 to 1) at a temperature in the ränge of 0 °C - 30 °C, preferably in the ränge of 5 °C - 10°C, and in the presence of a base. The quantity of protective agent, which can be an activated derivative of an acyl, preferably an acetyl or a benzoyl, of a sulfonyl, preferably a tosyl, or of an oxyformyl, preferably a benzyloxyformyl or an ethoxyformyl, is in the ränge of 0.8 - 3 equivalents with respect to the starting amino halogen-derivative, preferably in the ränge of 1 - 2 equivalents. The quantity of base, preferably NaOH, is in the ränge of 1 - 4 equivalents with respect to the starting amino halogen-derivative, preferably in the ränge of 2 - 3 equivalents. The reaction time is in the ränge of 1 - 4 hours, preferably 1 - 2 hours. c) substitution of the halogen of the protected amino halogen-derivative of formula IV with the appropriate aryloxy, so to obtain the protected aryloxypropylamine (or heteroaryloxypropylamine) of formula XIII.
A ^ r^
G
(IV) (XIII)
This reaction is carried out in an ether solvent, preferably polar, still more preferably tetrahydrofuran, at a temperature in the ränge of 25 °C - 65 °C, preferably 50 °C - 65 °C. The quantity of aryloxy, preferably obtained from o- cresol by means of a base, is in the ränge of 1 - 5 equivalents with respect to the starting protected amino halogen-derivative, preferably in the ränge of 2 - 4 equivalents. The quantity of base, preferably KOH, is in the ränge of 1 - 5 equivalents with respect to the starting protected amino halogen-derivative, preferably in the ränge of 2 - 4 equivalents. The reaction time is in the ränge of 5 - 20 hours, preferably in the ränge of 10 - 12 hours.
d) Deprotection of the formula Compounds (XIII) to obtain the ary-loxypropanolamine or heteroaryloxypropylamine of the invention, of formula (XI).
A - N A
(XIII) (XI)
The deprotection reaction type to be used varies in relation to the protective group and is well known in the art (see Greene et al. above). In the case of amides or carbamates, hydrolysis reactions in basic environment are used. If the carbamate is a benzylcarbamate, catalytic hydrogenolysis reactions are preferably utilised for the deprotection. Such hydrogenolysis reactions can be conducted with hydrogen, formic acid, ammonium formate, tertiary amine salts with formic acid or mixtures of formic acid and its salts.
The invention will be further illustrated by the following examples, which should
not be considered as limiting the object of the invention.
Stage a) - Activation of the hydroxyl
Preparation of a Compound of formula III
EXAMPLE 1
(XIV) (XV)
N-methyl-3-phenyl-3-hydroxy-propylamine (100g; 0.60moles) is loaded while being stirred at room temperature into methylene Chloride (400ml), obtaining a Solution. A Solution of SOCI2 (52.7ml; 0.73moles) is dripped in about 30 minutes
inio methylene Chloride (100ml), and the resulting liquid is stirred at room temperature for l-2h. The vacuum solvent is evaporated at 40°C until a solid residue is attained. Acetone (400ml) is added; the suspension is left to stir for 30 minutes and the solvent is removed by vacuum evaporation. Acetone (500ml) is once again added; the suspension is reflux heated (56°C) for Ih, then it is cooled to room temperature and left stirring for Ih. The solid is filtered, washing the panel with acetone (100ml) and it is dried in a 50°C oven so to obtain the Compound of formula XV (117.6g; 88% yield). Stage b) - Protection of the amino group Preparation of a Compound of formula IV
Ci
The protection of the amino group of the Compounds of formula III can be carried out in different modes known in the art. Several of these are illustrated in examples 2-7. Diagram of examples 2-3
ci


G-
HCl
(XV)


^TUVlAA/
o/^o"^ (XVIII)
EXAMPLE 2
Compound of formula XVII (G = benzyloxyformyl)
NaOH (63.8g; 1.59moles) is loaded at 5/10°C into H2O (800ml). Ethyl acetate is added (585ml). The Compound of formula XV is loaded (117g; 0.53moles) and fmally, in about Ih and still at 5/10°C, the benzyl chloroformate (83.5ml; 0.58moles) is loaded. The resulting mixture is stirred at 5/10°C for 2-3h. The 2

phases are separated; the organic phase is vacuum evaporated to form an oily residue (Compound of formula XVII; 191g; 94% yield), which is used as is for the subsequent step (see example 8). EXAMPLE 3
Compound of formula XVIII (G = ethoxyformyl)
In an analogous manner, the Compound of formula XVIII (which is used for such for the subsequent step, see example 8) is prepared by using ethyl chloroformate. Diagram of examples 4-6
ci ci
I
(XV)
G
HCl
(XVI)


o/
G=
G=
(XIX)
(XX)
(XXI)


EXAMPLE 4
Compounds of formula XIX (G = acetyl)
The Compound XV (55g; 0.25moles) is loaded at room temperature into methylene Chloride (550ml) and triethylamine (83ml; 0.6moles). Acetyl Chloride (21,3ml; 0.3moles) is added, still at room temperature and in about 30 minutes. The resulting mixture is stirred at room temperature for Ih. H2O (200ml) is added and the 2 phases are separated; the organic phase is vacuum evaporated to form an
oily residue (Compound XIX); 55g; 97% yield), which is used as is for the subsequent step (see example 8). EXAMPLE 5
Compound of formula XX (G = benzoyl)
In an analogous manner, the Compound of formula XX is prepared (which is used as is for the subsequent step, see example 8) by utilising benzoyl chloride. EXAMPLE 6
Compound of formula XXI (G = tosvl)
Gl
HC!
In an analogous manner, the Compound of formula XXI (which is used as is for the subsequent step, see example 8) is prepared by using tosyl chloride. Diagram of example 7
Gl
-N-
I
(XV)
G=
G
(XVI)
(XXII)
EXAMPLE 7
Compound of formula XXII (G = t-butoxyformyl')
H2O (135ml) and 30% NaOH (30ml; 0.3moles) are mixed at room temperature. The Compound of formula XV (30g; 0.14moles) and t-BuOH (135ml) are added. Finally, B0C2O (32.7g; 0.15moles) is loaded to portions in about 30 minutes. The resulting mixture is stirred at room temperature for Ih. The 2 phases are separated; the organic phase is vacuum evaporated to form an oily residue (Compound of formula XXII; 35g; 90% yield), which is utilised as such for the subsequent step (see example 8).

(XVI) (XXIII)
Stage c) - Substitution
Preparation of a Compound of formula V
EXAMPLE 8
KOH (135.9g; 2.18moles) is loaded at room temperature into THF (420ml), and this is heated to 50/60°C. Ö-cresol (230g; 2.13moles) is added into THF (230ml). The resulting mixture is stirred at 50/60°C for Ih, then a Solution of Compound XVI (168g; 0.53mol) is added into THF (170ml). The reaction mixture is reflux heated (66°C), and stirred for 12h. It is cooled to room temperature; the THF is evaporated, toluene (400ml) and 10% NaOH (100ml) are added; the 2 phases are separated; the organic phase is washed with 10% NaOH (2* 100ml). The combined organic phases are vacuum evaporated to form a small residue. Methanol (250ml) is added at 50/60°C, and the resultant is cooled at 0/5°C for 2- 3h. Filtering is then carried out, washing the panel with methanol (50ml), and the solid is vacuum dried at 50°C to obtain the Compound XXIII (154g; 74.4% yield). Stage d^ — Deprotection Preparation of a Compound of formula VII
EXAMPLE 9
The Compound of formula VII is obtained from the Compound of formula XXIII, by means of methods known in literature.

EXAMPLE 10 Compound of formula XXIV
(VII) (XXIV)
The Compound of formula XXIV is obtained from the CWe Claim:
1. Process for the synthesis of Compounds of formula I
where:
A is aryl or heteroaryl, Y is an aryl, comprising the following stages: a) halogenation of an amino alcohol of formula II:
QH
(II)
N H
where A has the above defmed meanings, in order to obtain the salified amino halogen-derivative of formula III:
HX
(III)
where X represents a halogen;
b) protection of the amino group of the salified amino halogen-derivative of formula III with a protective agent of the amino groups, in order to obtain the Compound of formula IV
(IV)
X
G

»here A and X have the above-defined meanings and G indicates a protector group of the amino groups having formula R-C(=0)-, where R is an alky], optionally substituted, residue, aryl residue or alkoxy residue, or having formula R'-S(=^0)2-, where R' indicates an alkyl, optionally substituted, residue or aryl residue; c) Substitution reaction on the protected amino halogen-derivative of formula IV by the anion of an aryl alcohol of formula Y-OH, where Y has the above-defmed meanings, to give the protected aryloxypropylamine or heteroaryloxypropylamine of formula XXV;
N
(J
(XXV)
d) deprotection of the amino group.
2. Process according to claim 1, where A is preferably phenyl, optionally substituted, or thiophenyl.
3. Process according to claim 2, where A is benzyl or tolyl.
4. Process according to claim 1, where Y is preferably a phenyl, a substituted phenyl or a naphthyl.
5. Process according to claim 4, where Y is tolyl, trihalomethyltolyl or alkoxytolyl.
6. Process according to claim 1, wherein said halogenation is obtained with a halogenation agent.
7. Process according to claim 6, wherein the halogenating agent is of SOX2, PX3, POX3, etc. type, where X indicates a halogen.
8. Process according to Claims 6 and 7 wherein the halogenating agent is thionyl Chloride.
9. Process according to Claims 6-8, wherein the quantiry of halogenating agent is in the ränge of 0.8 - 3 equivalents with respect to the starting amino alcohol of formula II, preferably in the ränge of 1 - 2 equivalents.
10. Process according to claim 1, wherein the reaction time of stage a) is in the ränge of 1 - 4 hours, preferably in the ränge of 1 - 2 hours.
11. Process according to claim 1, wherein the temperature of the reaction stage a) is in the ränge of 0° - 40 °C, preferably in the ränge of 20°C - 25 °C.
12. Process according to claim 1), where the reaction of stage a) is conducted in the presence of a halogenated solvent, preferably methylene Chloride.
13. Process according to claim 1, wherein the reaction stage b) occurs in the presence of a base.
14. Process according to claim 13, wherein the base utilised in the reaction stage b) e NaOH.
15. Process according to claim 1, wherein the reaction stage b) is carried out in the presence of a halogenated solvent, preferably methylene Chloride, and water.
16. Process according to claim 1, wherein the protective agent utilised in stage b) is benzyl chloroformate.
17. Process according to claim 1, wherein the quantity of the protective agent utilised in stage b) in order to obtain the Compound of formula IV is in the ränge of 0.8 - 3 equivalents with respect to the amino halogen-derivative of formula III, preferably in the ränge of 1 - 2 equivalents.
18. Process according to claims 1, 13 and 14, wherein the quantity of base utilised in stage b) is in the ränge of 1 - 4 equivalents with respect to the starting amino halogen-derivative III, preferably in the ränge of 2 - 3 equivalents.
19. Process according to claim 1, wherein the reaction time of stage b) is in the ränge of 1 - 4 hours, preferably in the ränge of 1 - 2 hours.
20. Process according to claim 1, wherein the temperature of the reaction stage b) is in the ränge of 0°C - 30 °C, preferably in the ränge of 5°C - 10
21. Process according to claim 1, where the anion of the ar>4 alcohol of formula Y-OH is obtained by means of the action of a base.
22. Process according to claim 1, where the reaction of stage c) is conducted in the presence of an ether solvent which is preferably polar and still more preferable tetrahydrofixran.
23. Process according to Claims 1 and 21, where the base utilised in stage c) is KOH.
24. Process according to Claims 1, 21 and 23, where the quantity of base is in the ränge of 1 - 5 equivalents with respect to the protected amino halogen-derivative of formula IV, preferably in the ränge of 2 - 4 equivalents.
25. Process according to claim 1, wherein the reaction time of stage c) is in the ränge of 5 - 20 hours, preferably in the ränge 10-12 hours.
26. Process according to claim 1, wherein the temperature of the reaction stage c) is in the ränge of 25°C - 65 °C, preferably in the ränge 50°C - 65 °C.
27. Process according to claim 1, wherein the deprotection stage d) occurs by means of hydrolysis reaction in basic environment or by means of catalytic hydrogenolysis.
28. Process according to claim 22, wherein the catalytic hydrogenolysis reaction is conducted with hydrogen, formic acid, ammonium formale, tertiary amine salts with formic acid or mixtures of formic acid and its salts.
ompound VII, by means of methods known in literature.

Documents:

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Patent Number 280065
Indian Patent Application Number 2038/CHENP/2009
PG Journal Number 06/2017
Publication Date 10-Feb-2017
Grant Date 08-Feb-2017
Date of Filing 13-Apr-2009
Name of Patentee EUTICALS SPA
Applicant Address Viale Bianca Maria, 25, 1-20122 Milano
Inventors:
# Inventor's Name Inventor's Address
1 BERTOLINI, GIORGIO VIA A. VILLA, 1, I-20099 SESTO SAN GIOVANNI
2 VERGANI, DOMENICO VIA BORROMINI 2, I-20046 BIASSONO
3 VERZOLA, BARBARA STRADA DEI RONCA'N.7, I-23877 PADERNO D'ADDA
PCT International Classification Number C07C209/68
PCT International Application Number PCT/EP07/60564
PCT International Filing date 2007-10-04
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 MI2006A001987 2006-10-16 Italy