SPIRO AMINO COMPOUNDS SUITABLE FOR THE TREATMENT
OF INTER ALIA SLEEP DISORDERS AND DRUG ADDICTION
FIELD OF THE INVENTION
The invention relates to novel spiro aminic compounds with Orexin 1 antagonist activity.
The invention also concerns a process for the preparation of those compounds, pharmaceutical compositions containing one or more compounds of Formula (Vl) and their use as antagonists of the orexin 1 receptor.
BACKGROUND OF THE INVENTION
The orexins are neuropeptides discovered in 1998 from two research groups. Orexin A is a 33 aminic acid peptide while orexin B is a 28 aminic acid peptide. The orexins are secreted from a discrete group of neurons in the lateral hypothalamus and they bind to G-coupled receptors, namely OX1 and OX2. The orexin 1 receptor (OX1 ) binds selectively the orexin A, while the orexin 2 receptor (OX2) binds both orexin A and orexin B.
Orexins are known to stimulate food consumption in rats, thus suggesting their role as modulators in food intake mechanisms.
Moreover it has been shown that orexins regulate the sleep architecture, thus making them a novel therapeutic approach to narcolepsy, as a treatment for insomnia and other sleep disorders. It has been recently shown that orexins are involved in addiction mechanisms, thus their modulations will make possible the treatment of compulsive disorders and drug addictions. Orexin receptors are located in mammals brain and they are involved in several pathologies.
In the international patent application WO2009/016560 trans-3-aza- biciclo[3.1.0]exane derivatives have been disclosed as a series of orexin antagonists.
Novel pyrrolidine and piperidine derivatives have been disclosed in WO2009/040730, N-aroil cyclic amine derivatives were disclosed in the international patent application WO02/090355 and piperazine compounds in WO03/051873, being all those novel structures proposed as antagonists of the orexin receptors.
A series of cyclic N-aroylamine derivatives has been disclosed in the international patent application WO2004/026866 as non-peptidic antagonists of the human orexin receptors. In particular 43 piperidine compounds, where the position beta to the nitrogen was substituted with hydrogen or methyl groups, have been tested for their activities against 0X1 and OX2 receptors.
Those documents describe compounds with activity at both receptors.
The object of the present invention is to provide compounds with selective antagonist activity at the orexin 1 receptor.
SUMMARY OF THE INVENTION
The object of the invention has been achieved by a spiro-amino compound of
Formula (Vl):
Vl
(Vl)
where
m is 1 or 2 or 3
n is 1 or 2,
R is selected from a 5- or 6-membered aromatic ring and a 5- or 6-membered heteroaromatic ring containing 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (d-C3)alkyl, halogen, (C3-C5)cycloalkyloxy, (C-ι-C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle containing at least one nitrogen atom;
P is a substituent Q or COQ, where Q is a group chosen from phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the
group consisting of (Ci-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy; methylcarboxy
or a pharmaceutically acceptable salt thereof.
In this invention compounds of Formula (Vl) may exist as R and S enantiomers and as racemic mixture. This invention includes in its scope of protection all the possible isomers and racemic mixtures. Wherever should be present further symmetry centres, this invention includes all the possible diastereoisomers and relative mixtures as well.
In a first embodiment, in the spiro-amino compound of Formula (Vl), P is Q. This is a compound of Formula (Via):
Via
In a second embodiment, in the spiro-amino compound of Formula (Vl), P is COQ. This is a compound of Formula (VIb):
VIb
A further aspect of this invention concerns a process for the preparation of a compound of Formula (Via) comprising the following steps represented in the scheme below:
IV
Via V
a) protecting a compound of Formula (I) with a BOC protecting group to obtain a compound of Formula (II);
b) reacting a compound of Formula (II) with strong bases and dimethylformamide, thus obtaining a compound of Formula (III);
c) adding an amine of Formula Q-NH2, where Q is selected from the group consisting of phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the group consisting of (C1-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy in the presence of a reducing agent to obtain a compound of Formula (IV);
d) cleaving the BOC group from the compound of Formula (IV) to obtain a compound of Formula (V);
e) reacting a compound of Formula (V) with RCOOH in the presence of coupling reagents or with the corresponding acyl chlorides RCOCI in the presence of a base, where R is selected from a 5- or 6-membered aromatic ring and a 5- or 6- membered heteroaromatic ring containing 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (d-C3)alkyl, halogen, (C3-C5)cycloalkoxy, (d-C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle containing at least one nitrogen atom.
In a further aspect, the invention concerns a process for the preparation of a compound of Formula (VIb) which comprises the following steps represented in the scheme below:
VIb VIII a) protecting a compound of Formula (I) with a BOC protecting group to obtain a compound of Formula (II);
b) reacting a compound of Formula (II) with strong bases and dimethylformamide, thus obtaining a compound of Formula (III);
f) making a reductive amination of the compound of Formula (III) to obtain an amine of Formula (VII);
g) reacting a compound of Formula (VII) with QCOOH in the presence of coupling reagents or with the corresponding acyl chlorides QCOCI in the presence of a base to obtain the amide of Formula (VIII), wherein Q is a group chosen from phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the group consisting of (Ci-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy;
h) cleaving the BOC group from the compound of Formula (VIII) and reacting with RCOOH in the presence of coupling reagents or with the corresponding acyl chlorides RCOCI in the presence of a base to give a compound of Formula VIb, wherein R is selected from a 5- or 6-membered aromatic ring and a 5- or 6-
membered heteroaromatic ring containing 1 to 3 heteroatoms selected from S, O e
N, such ring being substituted with one or two substituents selected from the group consisting of (Ci-C3)alkyl, halogen, (C3-C5)cycloalkyloxy, (C1-C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom.
In another aspect the invention concerns pharmaceutical compositions comprising a compound of Formula (Vl), preferably (Via), and a pharmaceutically acceptable carrier.
In another aspect the invention concerns a compound of Formula (Vl) as medicament, in particular it concerns its use for the manufacturing of a medicament for the treatment of pathologies where an antagonist of the 0X1 antagonist is needed, such as the treatment of obesity, sleep disorders, compulsive disorders, drug dependency, schizophrenia.
DETAILED DESCRIPTION OF THE INVENTION
The invention thus concerns a spiro-amino compound of Formula (Vl):
Vl
(Vl)
wherein
m is 1 or 2 or 3
n is 1 or 2,
R is selected from a 5- or 6-membered aromatic ring and a 5- or 6-membered heteroaromatic ring comprising 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (C-ι-C3)alkyl, halogen, (C3-C5)cycloalkyloxy, (C-ι-C3)alkylcarbonyl,
phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom;
P is a substituent Q or COQ, wherein Q is a group selected from phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from (d- C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy;
or a pharmaceutically acceptable salt thereof.
In a first embodiment, in spiro-amino compound of Formula (Vl), P is Q. This is a compound of Formula (Via):
Via
In this embodiment, preferably n is 2 and m is 1.
A preferred embodiment of the first embodiment of the invention concerns a piperidine ring compound with a spiro 3 carbon-atoms ring gamma to the nitrogen atom. R is preferably a phenyl or an heterocyclic ring.
More preferably when R is an heterocyclic ring, this is a thiazole ring, even more preferably a thiazole ring substituted with at least one substituent selected from the group consisting of methyl, phenyl, phenyl substituted with one or more halogens.
More preferably, when R is phenyl, it is a phenyl substituted with a group chosen from cyclopropil(C-ι-C3)alkyloxy, triazolil, pyrimidil.
Preferably Q is a pyridil ring, even more preferably a pyridil substituted with one or more substituents selected from the group consisting of trifluoromethyl, carboxy, methylcarboxy methyl and halogen.
The preferred compounds of the invention are selected from the group consisting of:
methyl 5-chloro-2-(((6-(5-(4-fluorophenyl)-2-methylthiazole-4-carbonyl)-6- azaspiro[2.5]octan-5-yl)methyl)amino)benzoate
(2-methyl-5-phenylthiazol-4-yl)(5-(((5-(trifluoromethyl)pyridin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(2-methyl-5-phenylthiazol-4-yl)(5-(((6-methylpyridin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(2-methyl-5-phenylthiazol-4-yl)(7-(((6-methylpyridin-2-yl)amino)methyl)-8- azaspiro[4.5]decan-8-yl)methanone
(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-
(cyclopropylmethoxy)phenyl)methanone
(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-(pyrimidin-2- yl)phenyl)methanone
(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-(4- fluorophenyl)-2-methylthiazol-4-yl)methanone
(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-(2H-
1 ,2,3-triazol-2-yl)phenyl)methanone
(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-
(pyrimidin-2-yl)phenyl)methanone
(5-(((5-fluoropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(7-(((5-chloropyridin-2-yl)amino)methyl)-8-azaspiro[4.5]decan-8-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(R)-(2-methyl-5-phenylthiazol-4-yl)(5-(((6-methylpyridin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(R)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(R)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-fluoro-2-
(pyrimidin-2-yl)phenyl)methanone
(R)-(5-methyl-2-(pyrazin-2-yl)phenyl)(5-(((6-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(2,5-dichlorophenyl)(5-(((4,6-dimethylpyrimidin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(S)-(2-(2H-1 !2!3-triazol-2-yl)phenyl)(5-(((5-chloropyridin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(S)-(2-methyl-5-phenylthiazol-4-yl)(5-(((4-methylpyrimidin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(S)-(2-methyl-5-phenylthiazol-4-yl)(5-(((5-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(2-methyl-5-phenylthiazol-4-yl)(5-(((5-methylpyrimidin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(S)-(2-methyl-5-phenylthiazol-4-yl)(5-(((6-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(2-methyl-5-phenylthiazol-4-yl)(5-(((6-methylpyridin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(S)-(5-(((4,6-difluoropyrimidin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2- methyl-5-phenylthiazol-4-yl)methanone
(S)-(5-(((4,6-dimethylpyrimidin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2- methyl-5-phenylthiazol-4-yl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-(pyrazin-
2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2- (pyrimidin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-fluoro-6-
(2H-1 ,2,3-triazol-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-fluoro-6-
(pyridin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-fluoro-6-
(pyrimidin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-fluoro-2- (2H-1 ,2,3-triazol-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-fluoro-2-
(pyrazin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-fluoro-2-
(pyridin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-fluoro-2-
(pyrimidin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-
(pyridin-2-yl)phenyl)methanone
(S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-
(pyrimidin-2-yl)phenyl)methanone
(S)-(5-(((5-fluoropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(S)-(5-(((6-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(S)-(5-(((6-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-
(2H-1 ,2,3-triazol-2-yl)phenyl)methanone
(S)-(5-(((6-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-
(pyrazin-2-yl)phenyl)methanone
(S)-(5-(((6-chloropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(5-methyl-2-
(pyrimidin-2-yl)phenyl)methanone
(S)-(5-(((6-fluoropyridin-2-yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(S)-(5-methyl-2-(2H-1 !2!3-triazol-2-yl)phenyl)(5-(((5-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(5-methyl-2-(2H-1 !2!3-triazol-2-yl)phenyl)(5-(((6-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(5-methyl-2-(pyrazin-2-yl)phenyl)(5-(((6-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(5-methyl-2-(pyrimidin-2-yl)phenyl)(5-(((5-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-(5-methyl-2-(pyrimidin-2-yl)phenyl)(5-(((6-(trifluoromethyl)pyridin-2- yl)amino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone
(S)-[1 ,1 '-biphenyl]-2-yl(5-(((4,6-dimethylpyrimidin-2-yl)amino)methyl)-6- azaspiro[2.5]octan-6-yl)methanone
(7-(((5-chloropyridin-2-yl)amino)methyl)-8-azaspiro[4.5]decan-8-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(2-methyl-5-phenylthiazol-4-yl)(7-(((6-methylpyridin-2-yl)amino)methyl)-8- azaspiro[4.5]decan-8-yl)methanone
(S)-(6-(((5-chloropyridin-2-yl)amino)methyl)-5-azaspiro[2.4]heptan-5-yl)(5-methyl- 2-(2H-1 ,2,3-triazol-2-yl)phenyl)methanone
(S)-(5-methyl-2-(2H-1 !2,3-triazol-2-yl)phenyl)(6-(((6-methylpyridin-2- yl)amino)methyl)-5-azaspiro[2.4]heptan-5-yl)methanone
(S)-(6-(((5-chloropyridin-2-yl)amino)methyl)-5-azaspiro[2.4]heptan-5-yl)(5-methyl- 2-(pyrimidin-2-yl)phenyl)methanone
In a first embodiment of the invention when m=2, n is preferably equal to 2.
In this embodiment:
- Q is preferably selected from pyridil, pyridil substituted with one or more substituents selected from (Ci-C3)alkyl, trifluoromethyl, halogen; and
- R is selected from phenyl and a 5-membered heteroaromatic ring comprising two heteroatoms selected from S, O e N, such ring being substituted with one substituent selected from (Ci-C3)alkyl, pyrimidil, thiazolil, phenyl optionally substituted with one or more halogen atoms. Preferred compounds when m=2 are:
(2-methyl-5-phenylthiazol-4-yl)(6-((6-methylpyridin-2-ylamino)methyl)-7- azaspiro[3.5]nonan-7-yl)methanone
(5-(4-fluorophenyl)-2-methylthiazol-4-yl)(6-((6-methylpyridin-2-ylamino)methyl)-7- azaspiro[3.5]nonan-7-yl)methanone
(6-((5-chloropyridin-2-ylamino)methyl)-7-azaspiro[3.5]nonan-7-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(6-((5-chloropyridin-2-ylamino)methyl)-7-azaspiro[3.5]nonan-7-yl)(5-(4- fluorophenyl)-2-methylthiazol-4-yl)methanone
.
(5-methyl-2-(2H-1 ,2,3-triazol-2-yl)phenyl)(6-((6-methylpyridin-2-ylamino)methyl)-7- azaspiro[3.5]nonan-7-yl)methanone
.
(5-methyl-2-(pyrimidin-2-yl)phenyl)(6-((6-methylpyridin-2-ylamino)methyl)-7- azaspiro[3.5]nonan-7-yl)methanone
(6-((5-chloropyridin-2-ylamino)methyl)-7-azaspiro[3.5]nonan-7-yl)(5-methyl-2-(2H- 1 ,2,3-triazol-2-yl)phenyl)methanone
(6-((5-chloropyridin-2-ylamino)methyl)-7-azaspiro[3.5]nonan-7-yl)(5-methyl-2- (pyrimidin-2-yl)phenyl)methanone
(2-methyl-5-phenylthiazol-4-yl)(6-((5-(trifluoromethyl)pyridin-2-ylamino)methyl)-7- azaspiro[3.5]nonan-7-yl)methanone
(5-(4-fluorophenyl)-2-methylthiazol-4-yl)(6-((5-(trifluoromethyl)pyridin-2- ylamino)methyl)-7-azaspiro[3.5]nonan-7-yl)methanone
(5-methyl-2-(2H-1 ,2,3-triazol-2-yl)phenyl)(6-((5-(trifluoromethyl)pyridin-2- ylamino)methyl)-7-azaspiro[3.5]nonan-7-yl)methanone
(5-methyl-2-(pyrimidin-2-yl)phenyl)(6-((5-(trifluoromethyl)pyridin-2-ylamino)methyl)- 7-azaspiro[3.5]nonan-7-yl)methanone
When m=3, n is preferably equal to 2.
In this embodiment:
- Q is preferably selected from pyridil, pyridil substituted with trifluoromethyl; pyridil substituted with (C1-C3)alkyl
- R is preferably selected from phenyl and a 5-membered heteroaromatic ring comprising two heteroatoms selected from S, O e N, such R being substituted with one or two substituents selected from (Ci-C3)alkyl, halogen, pyrimidil, thiazolil, phenyl optionally substituted with one or more halogen atoms.
More preferably, Q is pyridil substituted with trifluoromethyl or pyridil substituted with (C-i-C3)alkyl and R is 5-membered heteroaromatic ring comprising two heteroatoms selected from S, O e N, still more preferably thiazolil, such R being substituted with one or two substituents selected from (CrC3)alkyl and halogen.
Preferred compounds when m=3 are:
5
(2-methyl-5-p-tolylthiazol-4-yl)(7-((5-(trifluoromethyl)pyridin-2-ylamino)methyl)-8- azaspiro[4.5]decan-8-yl)methanone
(5-(4-fluorophenyl)-2-methylthiazol-4-yl)(7-((5-(trifluoromethyl)pyridin-2- ylamino)methyl)-8-azaspiro[4.5]decan-8-yl)methanone
(±)(2-methyl-5-phenylthiazol-4-yl)(7-(((6-methylpyridin-2-yl)amino)methyl)-8- azaspiro[4.5]decan-8-yl)methanone
(±)(7-(((5-chloropyridin-2-yl)amino)methyl)-8-azaspiro[4.5]decan-8-yl)(2-methyl-5- phenylthiazol-4-yl)methanone
(5-methyl-2-(2H-1 !2!3-triazol-2-yl)phenyl)(7-((5-(trifluoromethyl)pyridin-2- ylamino)methyl)-8-azaspiro[4.5]decan-8-yl)methanone
(5-methyl-2-(pyrimidin-2-yl)phenyl)(7-((5-(trifluoromethyl)pyridin-2-ylamino)methyl)- 8-azaspiro[4.5]decan-8-yl)methanone
When n=1 , m is preferably equal to 1.
In this embodiment:
- Q is preferably selected from pyridil, pyridil substituted with one or more halogens; pyridil substituted with (C-i-C3)alkyl;
- R is preferably selected from phenyl and a 5-membered heteroaromatic ring comprising two or three heteroatoms selected from S, O e N, such R being substituted with one or two substituent selected from (C1-C3)alkyl, halogen, pyrimidil, thiazolil, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom.
More preferably, Q is pyridil substituted with one or more halogens; pyridil substituted with (C1-C3)alkyl and R is phenyl substituted with one or two substituent selected from (C-i-C3)alkyl and a 5- or 6-membered heterocycle comprising at least one nitrogen atom.
Preferred compounds when m=1 are:
(6-((5-chloropyridin-2-ylamino)methyl)-5-azaspiro[2.4]eptan-5-yl)(5-methyl-2-(2H- 1 ,2,3-triazol-2-yl)phenyl)methanone
(6-((5-chloropyridin-2-ylamino)methyl)-5-azaspiro[2.4]eptan-5-yl)(5-methyl-2- (pyrimidin-2-yl)phenyl)methanone;
S)-(6-(((5-chloropyridin-2-yl)amino)methyl)-5-azaspiro[2.4]heptan-5-yl)(5-methyl-2- (2H-1 ,2,3-triazol-2-yl)phenyl)methanone
S)-(5-methyl-2-(2H-1 ,2,3-triazol-2-yl)phenyl)(6-(((6-methylpyridin-2- yl)amino)methyl)-5-azaspiro[2.4]heptan-5-yl)methanone
S)-(6-(((5-chloropyridin-2-yl)amino)methyl)-5-azaspiro[2.4]heptan-5-yl)(5-methyl-2- (pyrimidin-2-yl)phenyl)methanone
In a second embodiment, in the spiro-amino compound of Formula (Vl), P is COQ. This is a compound of Formula (VIb):
VIb
The invention also concerns a process for the preparation of a compound of Formula (Via) comprising the following steps represented in the below scheme:
IV
Via V
a) protecting a compound of Formula (I) with a BOC protecting group to obtain a compound of Formula (II);
b) reacting a compound of Formula (II) with strong bases and dimethylformamide, thus obtaining a compound of Formula (III);
c) adding an amine of Formula Q-NH2, where Q is selected from the group consisting of phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the group consisting of (C1-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy, in the presence of a reducing agent to obtain a compound of Formula (IV);
d) cleaving the BOC group from the compound of Formula (IV) to obtain a compound of Formula (V);
e) reacting a compound of Formula (V) with RCOOH in the presence of coupling reagents or with the corresponding acyl chlorides RCOCI in the presence of a base, wherein R is selected between a 5- or 6-membered aromatic ring and a 5- or 6-membered heteroaromatic ring comprising from 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (C-ι-C3)alkyl, halogen, (C3-C5)cycloalkyloxy, (d- C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom.
Furthermore the invention concerns a process for the preparation of a compound of Formula (VIb) which comprises the following steps represented in the scheme below:
VIb VIII a) protecting a compound of Formula (I) with a BOC protecting group to obtain a compound of Formula (II);
b) reacting a compound of Formula (II) with strong bases and dimethylformamide, thus obtaining a compound of Formula (III);
f) making a reductive amination of the compound of Formula (III) to obtain an amine of Formula (VII);
g) reacting a compound of Formula (VII) with QCOOH in the presence of coupling reagents or with the corresponding acyl chlorides QCOCI in the presence of a base to obtain the amide of Formula (VIII), wherein Q is selected from the group consisting of phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the group consisting of (C1-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy;
h) cleaving the BOC group from the compound of Formula (VIII) and reacting with RCOOH in the presence of coupling reagents or with the corresponding acyl chlorides RCOCI in the presence of a base to give a compound of Formula VIb, wherein R is selected between a 5- or 6-membered aromatic ring and a 5- or 6-
membered heteroaromatic ring comprising 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (Ci-C3)alkyl, halogen, (C3-C5)cycloalkyloxy, (C1- C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom.
Compounds of Formula (I) of step a) are either commercially available and/or described in literature. In step b), sec-BuLi could be used among strong bases. In the most preferred embodiment the invention concerns piperidine compounds with a spiro ring of three carbon atoms.
A further subject of the invention is also the preparation of compounds of Formula Via wherein m=1 and n=2, comprising the following steps:
a) reacting a compound of formula (I) with tertbutyl dicarbonate in an organic solvent to obtain a compound of Formula (II);
(I) (H)
b) reacting compounds of Formula (II) with a strong base and dimethylformamide; to give a compound of Formula
(H) (ill)
or reacting compounds of Formula (II) with a base and N,N,N'N'-tetramethyl ethylendiammine at -60 °C in an organic solvent and then with dimethylformamide at -78°C;
c) reacting compounds of Formula (III) with compounds of Formula Q-NH2, by using a reducing agent in an organic solvent for about 18 hours at room temperature to give compounds of Formula (IV), wherein Q is selected from the
group consisting of phenyl, pyridil, pyrimidil, quinolyl, isoquinolyl, quinoxalyl, benzofuranyl, imidazotriazolyl, being such Q optionally substituted with one or more substituents selected from the group consisting of (C1-C3)alkyl, halogen, trifluoromethyl, carbammido, methylcarbammido, carboxy, methylcarboxy;
d) reacting compounds of Formula (IV) with trifluoroacetic acid in a suitable organic for about 4 hours to give compounds of Formula (V);
(IV) (V) e) reacting compounds of Formula (V) with compounds of formula RCOOH by using a suitable condensing agent and a base in an organic solvent for about 18 hours to give compounds of Formula (Via), wherein R is selected from a 5- or 6- membered aromatic ring and a 5- or 6-membered heteroaromatic ring comprising 1 to 3 heteroatoms selected from S, O e N, such ring being substituted with one or two substituents selected from the group consisting of (d-C3)alkyl, halogen, (C3- C5)cycloalkyloxy, (C-ι-C3)alkylcarbonyl, phenyl optionally substituted with one or more halogen atoms, a 5- or 6-membered heterocycle comprising at least one nitrogen atom
(V) (Via) .
The process for the preparation of compounds of Formula Via where m=1 and n=2 provides for preferably the use of dichloromethane as organic solvent in step d) and NaBH(OAc)3 in dichloroethane in step c).
The preferred coupling agent in step e) is O-(Benzotriazol-i -yl) N,N,N',N'- tetramethyluronio hexafluorophosphate, diisopropyl ethyl amine as base, dimethyllformammide/dichloromethane as solvents.
According to the invention, the compounds are obtained using a simple process, easy to scale-up and avoiding lengthy and expensive preparation steps, obtaining high yield of a stable pharmaceutical grade compound.
The compounds of the invention as such or a pharmaceutically acceptable salt thereof could be used in medicine, in particular as antagonists of the Orexin 1 receptor.
They could be used in combination with an pharmaceutically acceptable carrier and, optionally, with suitable excipients, to obtain pharmaceutical compositions. The term "pharmaceutically acceptable carrier" means solvents, carrier agents, diluting agents and the like which are used in the administration of compounds of the invention.
Such pharmaceutical compositions can be administered by parenteral, oral, buccal, sublingual, nasal, rectal, topical or transdermal administration.
Compositions of this invention suitable for the oral administration will be conveniently discrete units such as tablets, capsules, cachet, powders or pellets, or as liquid suspension.
The tablets can contain also suitable excipients routinely used in pharmaceutical field such as pre-gelatinised starch, microcrystalline cellulose, sodium glycolate starch, talc, lactose, magnesium stearate, sucrose, stearic acid, mannitol.
Compositions for parenteral administration conveniently include sterile preparations.
Compositions for topical administration may conveniently be formulated as creams, pastes, oils, ointments, emulsions, foams, gels, drops, spray solutions and transdermal patches.
The compounds of the invention could be used for manufacturing a medicament for the treatment of pathologies which require the use of an antagonist of the OX1
receptor, such as the treatment of obesity and sleep disorders, compulsive disorders, drugs and alcohol dependencies, schizophrenia.
The invention will be now detailed by means of the following examples relating to the preparation of some invention compounds and to the evaluation of their activity against 0X1 receptor and OX2 receptor.
In the procedure that follows, after the starting materials, reference to a description is tipically provided. The starting material may not necessarely have been prepared from the description referred to. The stereochemistry of the Examples have been assigned on the assumption that the absolute configuration centers are retained.
Reagents used in the following examples were commercially available from various suppliers (for example Sigma-Aldrich, Acros or Apollo scientific) and used without further purifications. Solvents were used in dry form. Reaction in anhydrous environment were run under a positive pressure of dry N2
Microwave reactions were run on a Biotage Initiator 2.5 instrument.
Proton Nuclear Magnetic Resonance (1H NMR) spectra were recorded on Bruker Avance 400 MHz instrument. Chemical shifts are reported in ppm (δ) using the residual solvent line as internal standard. Splitting patterns are designated as: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; b, broad signal. When more than one conformer was detected the chemical shifts of the most abundant one is usually reported.
Mass spectra (MS) were run on a Ion Trap Thermo LCQ classic spectrometer, operating in positive ES(+) and negative ES(-) ionization mode.
HPLC spectra were performed using a Waters Alliance 2965 apparatus and UV- Vis detector Waters 2996. The cromatographic method (using Phenomenex Luna C18, 150*4.6, 5μ) was the following: 35 min of elution at 30°C, mobile phase composed of different acetonitrile/methanol/KH2PO4 (2OmM pH 2.5) mixtures, flow rate of 0.6 ml/min.
HPLC spectra for chiral purity determinations were performed using a Agilent 1200 apparatus and a UV detector DAD G1315D. The cromatographic method (using a Phenomenex LUX 5u cellulose-1 , 250*4.6mm) was the following: 30 min of
elution at 30 °C, mobile phase 90% n-hexane 10%ethanol + 0.1 %DEA, flow rate of
0.5 ml/min.
UPLC spectra were performed on a Waters Acquity UPLC-SQD instrument using an Acquity UPLC-BEH C18 column (1.7μM, 50x2.1 mm).
Purifications by means of preparative chiral HPLC were performed using a
Shimadzu Preparative Liquid Chromatograph LC-8A apparatus and a UV detector
SPD-20A. The cromatographic methods (using a Phenomenex LUX 5u cellulose-
1 , AXIA 250*21.20mm) were the following:
A: mobile phase 90% n-hexane 10% ethanol + 0.1 % DEA, flow rate of 10 ml/min . B: mobile phase 60% n-hexane 40% ethanol + 0.1 % DEA, flow rate of 10 ml/min .
C: mobile phase 93% n-hexane 7% isopropanol + 0.1 % DEA, flow rate of 10 ml/min .
D: mobile phase 95% n-hexane 5% isopropanol + 0.1 % DEA, flow rate of 10 ml/min .
E: mobile phase 80% n-hexane 20% ethanol + 0.1 % DEA, flow rate of 10 ml/min .
Flash silica gel chromatography was carried out on silica gel 230-400 mesh
(supplied by Merck AG Darmstadt, Germany); in a number of preparations,
Biotage automatic flash chromatography systems (Sp1 and lsolera systems) were performed, using Biotage silica cartridges.
Thin layer chromatography was carried out using Merck TLC plates Kieselgel 60F-
254, visualized with UV light, aqueous permanganate solution, iodine vapours.
Example 1 : preparation of intermediate 1 : 6-azaspiro [2.51octane hvdrobromide
Benzyl 6-azaspiro [2-5]octane-6-carboxylate (9g, 36 mmol), whose preparation has already been described for example in WO2008084300, was dissolved in HBr
35% in AcOH (10ml) at 0°C and maintained under stirring for 3 hours. The solution was treated with 200 ml of hexane. After having decanted the solvent, 80 ml of
Et2O were added. The solid obtained was filtered, washed with ether and hexane
(50ml), then dried under vacuum to obtain 6.3g of intermediate 1 (white cream solid).
MS (ESI) m/z: 1 12 [M+H]+
1HNMR(DMSO-Cl6) δ ppm 8.35 (m, 2H) 3.07 (m, 4H) 1.50-1.54 (m, 4H) 0.38 (s,
4H).
Example 2: preparation of intermediate 2: tetf-butyl 6-azaspiro [2.51octane-6- carboxylate
To a suspension of 6-azaspiro [2.5]octane hydrobromide (Intermediate 1 , 3.4g, 17.6mmol) in dichloromethane (50ml), which was cooled to 0°C, triethylamine (5.14ml, 3.9mmol) was added then a solution of tert-buthyl dicarbonate (4.24g, 19.4mmol) in dichloromethane (20ml) was added in 20 minutes. The clear solution was maintained under stirring at room temperature for 18 hours, then dichloromethane (50ml) was added and the organic solution was washed with water (2x20ml), HCI 0.5N (20ml) then water (2x20ml). The organic solvent was anhydrified (Na2SO4) and evaporated to give 3.7g of intermediate 2 (light yellow solid).
1HNMR(CDCI3) δ ppm 3.43 (m, 4H) 1.46 (s, 9H) 1.32 (m, 4H) 0.32 (s, 4H).
Example 3: preparation of intermediate 3: (±) terf-butyl 5-formyl-6-azaspiro [2.51octane-6-carboxylate
ter/-butyl 6-azaspiro [2.5]octane-6-carboxylate (Intermediate 2, 1 g, 4.73mmol) dissolved in 20ml of Et2O was cooled to -60°C, then N,N,N',N'-tetramethyl ethylendiamine (0.71 ml, 4.73mmol) and secBuLi 1.4M in hexane (4.05ml,
5.68mmol) were added. After 10 minutes at -60 °C, the temperature was raised to -
20 °C for 30 minutes, then the reaction was cooled to -78 °C and dimethylformamide (0.55ml, 7.09mmol, dissolved in 5 ml of Et2O) was added. After 30 minutes a saturated aqueous solution of NH4CI (8ml) was slowly added, then reaction was allowed to reach room temperature. Reaction was extracted with Et2O (3x 50ml), the organic solvent was dried (Na2SO4) and evaporated to
obtain a crude that was purified by silica gel chromatography (petroleum ether/ethylacetate from 95/5 to 85/15). (±) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate was obtained as light yellow solid (400mg).
MS (ESI) m/z 262 [M+Na]+.
1HNMR(CDCI3) δ ppm 9.65 (s, 1 H) 4.61 (m, 1 H) 4.02 (m, 1 H) 3.10 (m, 1 H) 2.08 (m, 1 H) 1.80 (m, 1 H) 1.51 (m, 1 H) 1.49 (s, 9H) 0.88 (m, 1 H) 0.35-0.42 (m, 4H). Example 4: preparation of intermediate 4: (±)tert-butyl 5-((6-methylpyridin-2- ylamino)methyl)-6-azaspiro[2.5]octane-6-carboxylate
(±) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate (Intermediate 3, 400mg, 1.67mmol) was dissolved in dichloroethane (5ml), then acetic acid (5 eq) and 2-amino 6 picoline (217mg, 2.0mmol) were added. After 3 hours at room temperature NaBH(OAc)3 (560mg, 2.63mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with ethylacetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; the obtained was purified by silica gel column chromatography (petroleum ether/ethyl acetate = 8/2 to 1/1 ). 360 mg of intermediate 4 were obtained as colourless oil.
MS (ESI) m/z: 354 [M+Na]+. 1HNMR(CDCI3) δ ppm 7.32 (m, 1 H) 6.44 (d, 1 H) 6.24 (d, 1 H) 4.65 (m, 1 H) 4.55 (m, 1 H) 4.10 (m, 1 H) 3.37 (m, 1 H) 3.05 (m, 1 H) 2.37 (s, 3H) 1.8-2.1 (m, 2H) 1.49 (s, 9H) 1.15 (m, 1 H) 0.85 (m, H) 0.25-0.48 (m, 4H).
Example 5: preparation of intermediate 5: (±)tert-butyl 5-((5-chloropyridin-2- ylamino)methyl)-6-azaspiror2.51octane-6-carboxvlate
(±) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate (Intermediate 3, 450mg, 1.88mmol) was dissolved in dichloroethane (5ml), then acetic acid (5 eq)
and 2-amino 5 chloropyridine (290mg, 2.25mmol) were added. After 3 hours at room temperature NaBH(OAc)3 (636mg, 3.0mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with ethyl acetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; crude product was purified by silica gel column chromatography using Petroleum ether/Ethyl acetate = 8/2. 240 mg of Intermediate 5 were obtained as colourless oil.
1HNMR (CDCI3) δ ppm 8.03 (d, 1 H) 7.33 (dd, 1 H) 6.33 (d, 1 H) 4.7 (m, 1 H) 4.57 (m, 1 H) 4.13 (m, 1 H) 3.85 (m, 1 H) 3.36 (m, 1 H) 2.99 (m, 1 H) 2.16 (m, 1 H) 1.88-1.95 (m, 1 H) 1.42 (s, 9H) 0.99 (m, 1 H) 0.82 (m, H) 0.45-0.50 (m, 2H) 0.28-0.32 (m, 2H). Example 6: preparation of intermediate 6: (±) tert-butyl 5-((5-trifluoromethylpyridin- 2-ylamino)methyl)-6-azaspiror2.51octane-6-carboxvlate
(±) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate (Intermediate 3, 450mg, 1.88mmol) was dissolved in dichloroethane (5ml), then acetic acid (5 eq) and 2-amino 5 trifluoromethylpyridine (365mg, 2.25mmol) were added. After 3 hours at room temperature NaBH(OAc)3 (636mg, 3.0mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with ethylacetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; the crude was purified by silica gel column chromatography, using a gradient dichloromethane to dichloromethane/Ethyl acetate = 95/5). 200 mg of Intermediate
6 as yellow oil were obtained.
MS (ESI) m/z : 408 [M+Na]+
1HNMR(CDCI3) δ ppm 8.35 (s, 1 H) 7.6 (d, 1 H) 6.5 (d, 1 H) 5.85 (m, 1 H) 5.40 (d,
1 H) 5.15 (m, 1 H) 3.75 (m, 1 H) 3.51 (m, 1 H) 2.25-2.45 (m, 2H) 1.40-1.75 (m, 10H)
0.3-0.55 (m, 4H).
Example 7: preparation of intermediate 7: (±) N-(6 azaspiror2.51octan-5-ylmethyl)-
(±) tert-butyl 5-((6-methylpyridin-2-ylamino)methyl)-6-azaspiro[2.5]octane-6- carboxylate (intermediate 4, 350mg, 1.05 mmol) was dissolved in dichloromethane (10ml) and cooled to 0°C, then trifluoroacetic acid (2ml) was added. After 1 hour at 0°C and 2 hours at room temperature the solution was evaporated, the residue re- dissolved in dichloromethane was washed with saturated NaHCO3 aqueous solution. The organic layers were dried (Na2SO4) and concentrated under vacuum, the crude was purified by silica gel column chromatography (CHCI3/MeOH = 8/2). 65 mg of Intermediate 7 as light yellow oil were obtained.
MS (ESI) m/z : 232 [M+H]+
1HNMR(CDCI3) δ ppm 7.32 (m, 1 H) 6.46 (d, 1 H) 6.32 (d, 1 H) 5.75 (m, 1 H) 3.45- 3.65 (m, 4H) 3.05 (m, 1 H) 2.42 (s, 3H) 2.06-2.18 (m, 1 H) 1.0-1.29 (m, 2H) 0.36- 0.52 (m, 4H).
Example 8: preparation of intermediate 8: (±) (6 azaspiror2.51octan-5-ylmethyl)-5- choropyridin-2-amine
(±) ferf-butyl 5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiro[2.5]octane-6- carboxylate (intermediate 5, 240mg, 0.68 mmol) was dissolved in dichloromethane (10ml) and cooled to 0°C, then trifluoroacetic acid (2ml) was added. After 1 hour at 0°C and 2 hours at room temperature the solution was evaporated, the residue dissolved in dichloromethane was washed with saturated NaHCO3 aqueous solution. The combined organic layers were dried (Na2SO4) and concentrated under vacuum; the crude was purified by silica gel column chromatography (gradient of dichloromethane to dichloromethane/MeOH = 9/1 ). 150 mg of Intermediate 8 as light yellow oil were obtained.
1HNMR(CDCI3) δ ppm 7.96 (d, 1 H) 7.30 (m, 1 H) 6.42 (d, 1 H) 6.25 (m, 1 H) 3.74 (m, 1 H) 3.37-3.55 (m, 3H) 2.93 (m, 1 H) 2.20 (m, 1 H) 2.0-2.66 (m, 1 H) 1.20 (m, 1 H) 1.04 (m, 1 H) 0.42-0.58 (m, 4H).
Example 9: preparation of intermediate 9: (±) N-(6 azaspiro[2.51octan-5-ylmethyl)- 5-(trifluoromethyl)pyridin-2-amine
(±) tert-butyl 5-((5-trifluoromethylpyridin-2-ylamino)methyl)-6-azaspiro[2.5]octane- 6-carboxylate (intermediate 5, 200mg, 0.520mmol) was dissolved in dichloromethane (10ml) and cooled to 0°C, then trifluoroacetic acid (2ml) was added. After 1 hour at 0°C and 18 hours at room temperature the solution was evaporated, the residue dissolved in dichloromethane was washed with saturated NaHCO3 aqueous solution. The combined organic layers were dried (Na2SO4) and concentrated under vacuum; the obtained crude was purified by silica gel column chromatography (gradient from dichloromethane/ethylacetate = 9/1 to dichloromethane/MeOH = 9/1 ). 60 mg of Intermediate 9 were obtained as light yellow oil.
MS (ESI) m/z: 286 [M+H]+ .
Example 10: preparation of intermediate 10: methyl 2-(6-azaspiro[2.51octan-5- ylmethylamino)-5-chlorobenzoate
To a solution of (±) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate
(intermediate 3) (160 mg, 0.669mmole) in dichloroethane (10 ml), methyl 2-amino- 5-chlorobenzoate (149 mg, 0.802mmole) and glacial AcOH (0.191 ml, 3.343mmole) were added. The reaction mixture was left to room temperature for 3 hours, then sodium triacetoxyborohydride (227 mg, 1.070mmole) was added and the reaction mixture was stirred at the same temperature overnight. The mixture was diluted with dichloromethane and washed with NaHCO3 saturated solution
(2x). The organic phase was separated on separating cartridge and evaporated, the obtained residue (273 mg, 0.669mmole) was dissolved in 3:1 trifluoroacetric acid:dichloromethane mixture (1.2:0.4 ml), by cooling in an ice bath. The reaction mixture was then stirred for 2 hours at room temperature. Solvents were evaporated, then the residue was dissolved in dichloromethane and the solution was washed with NaHCO3 saturated solution (2x). After evaporation of the organic phase the residue was purified by SPE-Si cartridge (5g) eluting with a mixture dichloromethane: MeOH (from dichloromethane to dichloromethane: MeOH 95: 5). 78 mg of intermediate 10 were obtained.
1 H NMR: (CDCI3) δ ppm 7.87-7.86 (d, 2H), 7.3-7.27 (dd, 1 H) 6.68-6-66 (d, 1 H) 3.87 (s, 3H) 3.25-3.21 (m, 2H) 3.15-3.1 1 (m, 1 H) 3.06-3.0 (m, 1 H) 2.86-2.79 (dt, 1 H) 2.74 (bs, 1 H) 1.98-1.91 (dt, 1 H) 1.78-1.72 (t, 1 H) 0.97-0.93 (m, 1 H) 0.88-0.83 (m, 1 H) 0.41 -0.35 (m, 2H) 0.32-0.28 (m, 2H) Example 1 1 : Preparation of intermediate 12: (S)-2-[tert-butoxycarbonyl-(2- methoxycarbonyl- ethvD-aminoi-succinic acid 4-methyl ester
To a solution of (S)-2-amino-succinic acid 4-methyl ester hydrochloride (intermediate 1 1 , 25Og, 1.36mol) in water (600ml) cooled to 0°C was added triethylamine (474ml, 3.4mol) and methl acrylate (368ml, 4.09mol). The mixture was stirred vigorously and warmed to room temperature. After washing with petroleum ether (2x2L), tert-butanol (200ml) and BoC2O (37Og, 1.70mol) were added and vigorous stirred continued for 16 hours. The mixture was washed with petroleum ether (2x2L). The aqueous solution was cooled to 0°C and the value of pH was adjusted to 3.0 with concentrated HCI. The product was extracted with ethyl acetate (3x1 L) and the organic extracts were combined, washed with saturated NaCI (1 L), dried (Na2SO4) and evaporated to give 42Og (yield: 92%) of
(S)-2-[tert-butoxycarbonyl-(2-methoxycarbonyl-ethyl)-amino]-succinic acid 4- methyl ester.
1HNMR (CDCI3) δ ppm 5.45 (s, 1 H), 4.44 (m, 1 H), 3.80-3.87 (m, 1 H), 3.71 (s, 3H), 3.68 (s, 3H), 3.45-3.53 (m, 1 H), 3.20 (m, 1 H), 2.57-2.90(m, 3H), 1.43 (s, 9H)
Example 12: Preparation of intermediate 13: (S)-4-oxo-piperidine-1 ,2-dicarboxylic acid 1 -tert-butyl ester tert-butylamine salt
To a solution of (S)-2-[tert-Butoxycarbonyl-(2-methoxycarbonyl-ethyl)-amino] - succinic acid 4-methyl ester (intermediate 12, 42Og, 1.35mol) in THF (2L) under nitrogen cooled to 0°C was added NaOMe/MeOH (1.5L, 2.7M) in half an hour. The resulting yellow solution was stirred at 85 °C for 3 hours (after 1 hour a suspension was obtained). THF (1.5L) was distilled off under the reduced pressure and water (2L) was added. The resulting mixture was stirred at 1 10°C for 20 hours. The mixture was washed with ethyl acetate (2x1 L). The aqueous solution was cooled to 0°C and the value of pH was adjusted to 2.5 with concentrated HCI. The product was extracted with ethyl acetate (3x1 L) and the organic extracts were combined, washed with saturated NaCI (1 L), dried (Na2SO4) and filtered. The filtrate was cooled to 0°C and tert-butylamine (145ml, 1.35mol) was added with stirring. The yellow solid was collected by filtration and dried, then boiled in isopropyl alcohol (1.5L). The suspension was cooled to 5°C and collected by filtration to give 18Og of intermediate 3 (light white solid, yield:45%).
1HNMR (D2O) δ ppm 8.94 (s, 1 H), 5.10 (m, 1 H), 4.06 (m, 1 H), 3.70 (m, 1 H),
2.86(m, 2H), 2.55 (m, 2H), 1.47 (s, 9H)
[ α ]D 25-14.4(c1.0, H2O)
Example 13: Preparation of intermediate 14: (S)-4-oxo-piperidine-1 ,2-dicarboxylic acid 2-benzyl ester 1 -tert-butyl ester
To a suspension of (S)-4-oxo-piperidine-1 ,2-dicarboxylic acid 1 -tert-butyl ester tert- butylamine salt (intermediate 13, 30Og, 0.95mol) in ethyl acetate (2.5L) stirred at 0°C was slowly added aqueous HCI 0.5N (3L) saturated with NaCI. After complete dissolution was observed, the organic layer was decanted, and washed with saturated NaCI, dried (Na2SO4) and evaporated to yield 20Og of acid derivative. To a solution of acid derivative (20Og, 0.82mol) in anhydrous dichloromethane (1.5L) was added benzyl alcohol (88.9g, 0.82mol), N^'-dicyclohexylcarbodiimide (186g, 0.91 mol), 4-dimethylaminopyridine (1 1 g, 0.09 mol) at 0°C, then warmed to room temperature, and stirred at room temperature for 10 hours. The mixture was filtered and the liquid phase was evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1 ). (S)-4- Oxo-piperidine-1 ,2-dicarboxylic acid 2-benzyl ester 1 -tert-butyl ester was obtained as colourless oil (21 Og), yield:73%.
1HNMR (CDCI3) δ ppm 7.34-7.41 (m, 5H), 5.20 (s, 2H), 4.91 (m, 1 H), 4.08 (m, 1 H), 3.70(m, 1 H), 2.82 (m, 2H), 2.51 (m, 2H), 1.45 (d, 9H)
Example 14: Preparation of intermediate 15: (S)-4-methylene-piperidine-1 ,2- dicarboxylic acid 2-benzyl ester 1 -tert-butyl ester
To a suspension of methyl(triphenyl)phosphonium bromide (248g, 0.69mol) in anhydrous toluene (1 L) was added sodium hexamethyldisilazide (258ml, 0.69mol) at 0°C, after addition was completed, the reaction mixture was warmed to room temperature, and stirred at room temperature for 1 hour, then cooled to 0°C and
the solution of (S)-4-oxo-piperidine-1 ,2-dicarboxylic acid 2-benzyl ester 1 -tert-butyl ester (intermediate 14, 21 Og, 0.63mol) in anhydrous toluene (0.5L) was added. The resulting mixture was warmed to room temperature, and stirred at room temperature for 1 hour, added water (500ml), extracted with ethyl acetate. The combined organic extracts were dried (Na2SO4), filtered and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1 ). (S)-4-Methylene-piperidine-1 ,2-dicarboxylic acid 2- benzyl ester 1 -tert-butyl ester was obtained as colourless oil (12Og), yield:57.4%. 1HNMR (CDCI3) δ ppm 7.29-7.41 (m, 5H), 4.73-5.25 (m, 5H), 4.14 (m, 1 H), 3.06 (m, 1 H), 3.80(m, 1 H), 2.47(m, 1 H), 2.13 (m, 2H), 1.35 (d, 9H)
Example 15: Preparation of intermediate 16: (S)-6-aza-spiro[2.51octane-5,6- dicarboxylic acid 5-benzyl ester 6-tert-butvl ester
To a solution of (S)-4-methylene-piperidine-1 ,2-dicarboxylic acid 2-benzyl ester 1 - tert-butyl ester (intermediate 15 prepared by Method A, 12Og, 0.36mol) in anhydrous THF (1 L) was added diazomethane in ether (500ml) [which was prepared from methyl-3-nitro-1 -nitroxoguanide (213g) in 40% KOH (1 L)] at -25 °C to -35 °C slowly under the protection of nitrogen and warmed to room temperature slowly (about 4 hours) and stirred at room temperature for 10 hours. The mixture is filtered and the liquid phase was evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1 ). (S)-6- Aza-spiro[2.5]octane-5,6 -dicarboxylic acid 5-benzyl ester 6-tert-butyl ester was obtained as colourless oil (1 1 Og), yield:88%.
1HNMR (CDCI3) δ ppm 7.36 (m, 5H), 5.14-5.33 (m, 2H), 4.90 (m, 1 H), 3.98 (m, 1 H), 3.17(171, 1 H), 2.19(171, 1 H), 1.92 (m, 1 H), 1.42 (d, 9H), 0.80 (m, 1 H), 0.10-0.30 (m, 4H)
Example 16: Preparation of intermediate 17: (S)-6-aza-spiror2.51octane-5,6- dicarboxylic acid 6-tert-butyl ester
To a solution of (S)-6-aza-spiro[2.5]octane-5,6-dicarboxylic acid 5-benzyl ester 6- tert-butyl ester (intermediate 16, 1 1 Og, 0.32mol , ee:66%) in anhydrous methanol
(1 L) was added Pd/BaSO4 (5Og) under hydrogen, the reaction mixture was stirred at room temperature for overnight. The resulting mixture was filtered and the liquid phase was evaporated to give 68g of (S)-6-aza-spiro[2.5]octane-5,6-dicarboxylic acid 6-tert-butyl ester (light white solid, yield:85%) which was recrystallized with PE/EtOAc (4:1 ) to give 38g of (S)-6-aza-spiro[2.5]octane-5,6-dicarboxylic acid 6- tert-butyl ester.
1HNMR (CDCI3) δ ppm 12.67 (s, 1 H), 4.60 (m, 2H), 3.85 (m, 1 H), 3.10 (m, 1 H), 2.08 (m, 1 H), 1.79 (m, 1 H), 1.40 (d, 9H), 0.84 (m, 1 H), 0.28-0.32 (m, 4H) Example 17: Preparation of intermediate 18: (S)-5-hvdroxymethyl-6-aza- spiro[2.51octane-6- carboxylic acid tert-butyl ester
To a solution of (S)-6-aza-spiro[2.5]octane-5,6-dicarboxylic acid 6-tert-butyl ester (intermediate 17, 35g, 0.122mol ) in anhydrous THF (300ml) was added BH3/THF (1 M, 360ml, 0.365mol) under nitrogen at 0°C. After the addition was completed, the reaction mixture was warmed to room temperature and stirred at room temperature for overnight. The resulting mixture was evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from
10/1 to 5/1 ). (S)-5-Hydroxymethyl-6-aza-spiro[2.5]octane-6-carboxylic acid tert- butyl ester was obtained as colourless oil (31 g), yield:86%.
1HNMR (CDCI3) δ ppm 4.40 (m, 1 H), 4.01 (m, 1 H), 3.66 (m, 1 H), 3.06 (m, 1 H), 2.03 (m, 1 H), 1.87 (m, 1 H), 1.50 (s, 9H), 1.02 (d, 1 H), 0.85 (d, 1 H), 0.27-0.43 (m, 4H);
MS Calcd.: 241 ; MS Found: 142 ([M-100+1 ]+).
Alternatively Intermediate 18 was prepared from Intermediate 16. To a suspension of lithium aluminium hydride (0.57g, 15mmol) in anhydrous THF (30ml) was added the solution of (S)-6-aza-spiro[2.5]octane-5,6-dicarboxylic acid 5-benzyl ester 6- tert-butyl ester (intermediate 16, 3.45g, l Ommol) in THF(20ml) at 0°C, after the addition was completed, the reaction mixture was stirred at 0°C for 2 hours. The resulting mixture was quenched with Na2SO4-I OH2O, filtered and the filtration was dried (Na2SO4) and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1 ). (S)-5- Hydroxymethyl-6-aza-spiro[2.5]octane-6-carboxylic acid tert-butyl ester was obtained as colourless oil (2.0 g), yield:83%.
Example 18 : preparation of intermediate 19 : (S) terf-butyl 5-formyl-6-azaspiro [2.51octane-6-carboxylate
To (S)-tert-butyl 5-(hydroxymethyl)-6-azaspiro[2.5]octane-6-carboxylate
(Intermediate 18, 2Og, 82.0 mmol) dissolved in 80ml of DCM, TEMPO (2.6g, 16mmol) and BAIB (29.3g, 90mmol) were added. After 2 hours at 25 °C, the reaction is diluted with DCM (150ml), washed with an aqueous solution of Na2S2O3 then with water, dried (Na2SO4) and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether to petroleum ether/ethylacetate 95/5). (S) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate was obtained as light yellow solid (7g).
1HNMR (CDCI3) δ ppm 9.66 (s, 1 H), 4.68 (m, 1 H), 3.97 (m, 1 H), 3.13 (m, 1 H), 2.07 (m, 1 H), 1.83 (m, 1 H), 1.50 (m, 10H), 0.88 (m, 1 H), 0.35-0.50 (m, 2H), 0.20- 0.30 (m, 2H) Example 19 : preparation of intermediates 20-24
General procedure 1 :
(S) tert-butyl 5-formyl-6-azaspiro [2.5]octane-6-carboxylate (Intermediate 19, 1 eq) was dissolved in dichloroethane (2.5-5ml/mmol), then acetic acid (5 eq) and the corresponding 2-amino pyridine (1.2 eq) were added. After 1 -3 hours at room temperature NaBH(OAc)3 (1.6eq) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with ethyl acetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; crude product was purified by silica gel column chromatography using Petroleum ether/Ethyl acetate = 8/2 to 1/1 or DCIWMeOH = 98/2 to 9/1. Intermediates 20-24 were obtained as oils.
According to general procedure 1 the following intermediates were prepared:
Intermediates 20-24 characterization:
Example 20: Preparation of intermediate 25: (S)-5-(1 ,3-dioxo-1 ,3-dihvdro-isoindol- 2- ylmethyl)-6-aza-spiro[2.51octne-6-carboxylic acid tert-butyl ester
To a solution of (S)-5-hydroxymethyl-6-aza-spiro[2.5]octane-6-carboxylic acid tert- butyl ester (intermediate 18, 10g, 42mmol) in THF (300ml) was added triphenyl
phosphine (13g, 50mmol), phthalimide (6.2g, 42mmol) and diethyl azodicarboxylate (21.75g, 50mmol) at 0°C under the protection of nitrogen. After the completion of addition, the reaction mixture was warmed to room temperature, and stirred at room temperature for 10 hours. The resulting mixture was evaporated to obtain crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1 ). (S)-5-(1 ,3-Dioxo-1 ,3-dihydro- isoindol-2-ylmethyl)-6-aza-spiro[2.5]octne-6-carboxylic acid tert-butyl ester was obtained as light white solid (13g, yield:83.6%).
1HNMR(400 MHz5CDCI3) δ ppm 7.73-7.92 (m, 5H), 4.79 (m, 1 H), 4.51 (m, 1 H), 4.08 (m, 1 H), 3.48(m, 1 H), 3.33(m, 1 H), 2.21 (m, 1 H), 1.93(m, 1 H), 1.25(m, 1 H), 1.09 (s, 9H), 0.88 (m, 1 H), 0.33-0.61 (m, 4H)
Example 21 : Preparation of intermediate 26: (S)-5-aminomethyl-6-aza- spiro[2.51octane-6- carboxylic acid tert-butvl ester
To a solution of (S)-5-(1 ,3-dioxo-1 ,3-dihydro-isoindol-2-ylmethyl)-6-aza-spiro
[2.5]octne-6-carboxylic acid tert-butyl ester (intermediate 25, 12g, 32.4mmol) in ethanol (150ml) was added hydrazine hydrate (8.1 g, 162mmol). After the completion of addition, the reaction mixture was stirred at 80 °C for 5 hours. The resulting mixture was filtered, and the filtrate was evaporated to obtain crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 1/1 ). (S)-5-Aminomethyl-6-aza-spiro[2.5]octane- 6-carboxylic acid tert-butyl ester was obtained as colorless oil (6.88g, yield 86%).
1HNMR(400 MHz5CDCI3) δ ppm 4.28 (m, 1 H), 4.06 (m, 1 H), 3.20 (m, 1 H), 2.96 (m, 1 H), 1.79 (m, 1 H), 2.10(m, 1 H), 1.89(m, 1 H), 1.49(s, 9H), 0.95(d, 1 H), 0.80 (d, 1 H), 0.27-0.44 (m, 4H);
Example 22: preparation of intermediates 27-33
General procedure 2
To the solution of (S)-5-aminomethyl-6-aza-spiro[2.5]octane-6-carboxylic acid tert- butyl ester (intermediate 26, 2mmol) in isopropanol (50ml) and N, N- diisopropylethylamine (3mmol) was added ArI -X (where X= 2Cl, 2F or 2Br;
1.1 mmol). After the completion of addition, the reaction mixture was stirred until conversion of the staring material and, depending on ArI -X, in a temperature range -20° to 90 °C. The resulting mixture was evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 3/1 ).
According to general procedure 2 the following intermediates were prepared:
Example 23: preparation of intermediates 34- 45
General procedure 3:
A selection of Intermediates 20-24 and 27-33 (1 eq) were dissolved in dichloromethane (10ml/mmol) and cooled to 0°C, then trifluoroacetic acid (2ml/mmol) was added. After 1 hour at 0°C and 2 hours at room temperature the solution was evaporated, the residue re-dissolved in dichloromethane was washed with saturated NaHCO3 aqueous solution. The organic layers were dried (Na2SO4) and concentrated under vacuum. The crude was purified by silica gel column chromatography (CHCI3/MeOH = 8/2). Intermediates were obtained as light yellow oils.
General procedure 4:
To the solution of a selection of intermediates 20-24 and 27-33 in ethyl acetate was added HCI(g)/EtOAc (4.0M) at 0°C. After the completion of addition, the reaction mixture was stirred at 0°C for 1 hour. The resulting solids were collected by filtration, and washed with petroleum ether and dried to give intermediates as hydrochlorides.
According to general procedure 3 or 4 the following intermediates were prepared:
Intermediates 34-45 characterization:
Example 24: preparation of intermediates 46-50
General procedure 5
Intermediates 34-45 (1 eq) were dissolved in dry dichloromethane (10ml/mmol) at
0°C with TEA (3 eq), the corresponding 2-lodo benzoyl chloride dissolved in dry dichloromethane was added. After 2 hours the mixture was poured in aqueous
NaHCO3 and extracted with dichloromethane. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; crude product was purified by silica gel column chromatography (Hexane/AcOEt 9/1 ).
According to general procedure 5 the following intermediates were prepared:
Intermediates 46-50 characterization:
Example 25: Preparation of intermediate 52: (2S,4R)-4-(tert-butyl-dimethyl- silanyloxy)- pyrrolidine-1 ,2-dicarboxylic acid 1 -tert-butyl ester 2-methyl ester
Imidazole (21.7g, 320mmol) and tert-butyldimethylsilyl chloride (26.2g, 170 mol) were added to a solution of (2S,4R)-4-hydroxy-pyrrolidine-1 ,2- dicarboxylic acid 1 - tert-butyl ester 2-methyl ester (intermediate 51 , 38.7g, 160mmol) in
dichloromethane (700ml) at 0°C, the mixture was maintained under stirring at room temperature for 4 hours. The mixture was filterd, the liquid phase was then washed with HCI 0.5N (500ml), saturated NaHCO3 aqueous (500ml) then brine (2x500ml). The organic solvent was dried (Na2SO4) and evaporated to give 58g of intermediate 52 (yellow solid, yield: 100%).
1HNMR (400 MHz, CDCI3) δ ppm 4.34-4.46 (m, 2H), 3.75 (m, 3H), 3.58-3.65 (m, 1 H), 3.32-3.44 (m, 1 H), 2.20 (m, 1 H), 2.04 (m, 1 H), 1.48-1.43 (d, 9H), 0.92 (s, 9H), 0.05 (s, 6H). Example 26: Preparation of intermediate 53: (2S,4R)-4-(tert-butyl-dimethyl- silanyloxy)-2- hvdroxymethyl-pyrrolidine-i -carboxylic acid tert-butvl ester
To a suspended solution of lithium aluminium hydride (7.2g, 190mmol) in THF (200ml) under nitrogen (2S,4R)-4-(tert-Butyl-dimethyl-silanyloxy)-pyrrolidine- 1 ,2- dicarboxylic acid 1 -tert-butyl ester 2-methyl ester (intermediate 52, 58g, 160mmol) in THF (300ml) was added dropwise at 0°C. The solution was maintained under stirring at 0°C for 2 hours, then Na2SO4-I OH2O was added and the mixture was filtrated, the filtrate was concentrated to give 51 .4g of intermediate 53 (yellow oil, yield: 96%).
1HNMR (400 MHz, CDCI3) δ ppm 4.95 (m, 1 H), 4.30 (m, 1 H), 4.15 (m, 1 H), 3.71 (m, 1 H), 3.57 (m, 1 H), 3.45 (m, 1 H), 3.36 (m, 1 H), 1.98 (m, 1 H), 1.49 (s, 9H), 0.89 (s, 9H), 0.06 (s, 6H)
Example 27: preparation of intermediate 54: (2S,4R)-4-(tert-butyl-dimethyl- silanyloxy) -2-(4-nitro-benzoyloxymethyl)-pyrrolidine-1 -carboxylic acid tert-butyl ester
(2S,4R)-4-(Tert-butyl-dimethyl-silanyloxy)-2-hydroxymethyl-pyrrolidine-1 -carboxylic acid tert-butyl ester (intermediate 53, 51.4g, 155mmol) dissolved in 500ml of dichloromethane was cooled to 0°C, then p-nitrobenzoic acid (28.5g, 171 mmol), ty/V-dicyclohexylcarbodiimide (35.2g, 171 mmol) and 4-dimethylaminopyridine (1.9Og, 1.60mmol) were added. The mixture was maintained under stirring at room temperature for 18 hours, then filtrated; the filtrate was concentrated to obtain crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 15/1 to 10/1 ). (2S,4R)-4-(tert-Butyl-dimethyl-silanyloxy)-2-(4-nitro- benzoyloxymethyl)-pyrrolidine-1 -carboxylic acid tert-butyl ester was obtained as white solid (7Og, yield: 94%).
1HNMR (400 MHz, CDCI3) δ ppm 8.32 (d, 2H), 8.23 (d, 2H), 4.44-4.56 (m, 4H), 3.42-3.58 (m, 2H), 2.08 (m, 1 H), 1.96 (m, 1 H), 1.48 (s, 9H), 0.89 (s, 9H), 0.08 (s, 6H)
Example 28: preparation of intermediate 55: (2S,4R)-4-hvdroxy-2-(4-nitro-benzoyl oxymethvD-pyrrolidine-i -carboxylic acid tert-butyl ester
To the solution of (2S,4R)-4-(tert-Butyl-dimethyl-silanyloxy)-2-(4-nitro-benzoyl oxymethyl)-pyrrolidine-1 -carboxylic acid tert-butyl ester (intermediate 54, 35g,
72.9mmol) in 300 ml of pyridine was added 70% pyridine hydrofluoride (200ml) dropwise at 0°C. After 2 hours at room temperature, then temperature was cooled
to 0°C and 1500ml of water was added, then reaction was allowed to reach room temperature. Reaction was extracted with ethyl acetate (2x1.5L), the organic solvent was washed with 1 N HCI (2.0L), saturated NaHCO3 aqueous (2.0L) and brine (2.0L), dried (Na2SO4) and evaporated to give 23g of intermediate 55 (yellow solid, yield: 92%).
1HNMR (400 MHz, CDCI3) δ ppm 8.32 (d, 2H), 8.20 (d, 2H), 4.34-4.59 (m, 4H), 3.48-3.70 (m, 2H), 1.99-2.20 (m, 3H), 1.46 (s, 9H)
Example 29: preparation of intermediate 56: (S)-2-(4-nitro-benzoyloxymethyl)-4- OXO- pyrrolidine-1 -carboxylic acid tert-butyl ester
To a solution of oxalyl chloride (23.5ml, 246mmol) in dichloromethane (400ml), which was cooled to -75°C, dimethyl sulfoxide (35ml, 492mmol) in dichloromethane (60ml) was added in 20 minutes. After 30 minutes at -70 °C, a solution of (2S,4R)-4-hydroxy-2-(4-nitro-benzoyloxymethyl)-pyrrolidine-1 - carboxylic acid tert-butyl ester (intermediate 55, 45g, 123mmol) in dichloromethane (300ml) was added dropwise. After 2 hours at -70 °C, N, N- diisopropylethylamine (60ml) was added in 10 minutes. After 25 minutes at -60 °C and 30 minutes at room temperature dichloromethane (200ml) was added. The organic solvent was washed with 0.5N HCI (500ml), water (500ml) and brine (500ml), dried (Na2SO4) and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 5/1 to 3/1 ). (S)-2-(4- Nitro-benzoyloxymethyl)-4-oxo-pyrrolidine-1 -carboxylic acid tert-butyl ester was obtained as white solid (28.5g, yield: 70%).
1HNMR (400 MHz, CDCI3) δ ppm 8.32 (d, 2H), 8.12 (d, 2H), 4.69-4.84 (m, 2H), 4.38 (m, 1 H), 4.01 (m, 1 H), 3.71 (m, 1 H), 2.94 (m, 1 H), 2.56 (m, 1 H), 1.51 (s, 9H)
Example 30: preparation of intermediate 57: (S)-4-methylene-2-(4-nitro- benzoyloxymethyl) -pyrrolidine-i -carboxylic acid tert-butyl ester
Methytriphenylphosphonium bromide (38g, 106mmol) dissolved in 300ml of toluene was cooled to 0°C, then added sodium hexamethyldisilazide (48.3ml, 93.7mmol) was added dropwise. After 2 hours at room temperature, The temperature was cooled to 0°C, a solution of (S)-2-(4-nitro-benzoyloxymethyl)-4- oxo-pyrrolidine-1 -carboxylic acid tert-butyl ester (intermediate 56, 15.5g, 42.6mmol) in 300ml of toluene was added. After 10 minutes 500ml of water was slowly added, then reaction was allowed to reach room temperature. The organic solvent was washed with brine (500ml), dried (Na2SO4) and evaporated to obtain crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 15/7 to 7/1 ). (S)-4-Methylene-2-(4-nitro-benzoyloxymethyl)-pyrrolidine-1 - carboxylic acid tert-butyl ester was obtained as yellow solid (6.82g, yield 46%). 1HNMR (400 MHz, CDCI3) δ ppm 8.29 (d, 2H), 8.23 (d, 2H), 5.07 (s, 2H), 4.35- 4.50 (m, 3H), 4.16 (m, 1 H), 3.93 (m, 1 H), 2.89 (m, 1 H), 2.52 (m, 1 H), 1.48 (s, 9H)
Example 31 : preparation of intermediate 58: (S)-6-(4-nitro-benzoyloxymethyl)-5- aza- spiror2.41heptane-5-carboxylic acid tert-butvl ester
Methyl-3-nitro-1 -nitroxoguanide (90 g) was added slowly to a solution of KOH
(66g) in water (130ml) and Et2O (250ml) at 0°C. After 30 minutes at 0°C, the organic phase was separated to get the solution of diazomethane.
(S)-4-Methylene-2-(4-nitro-benzoyloxymethyl)-pyrrolidine-1 -carboxylic acid tert- butyl ester (intermediate 57, 1 1.3g, 31.2mmol) was dissolved in 120ml of THF was added palladiumdiacetate (3.Og). After 2 hours at room temperature, the temperature was cooled to -60 °C; the solution of diazomethane was added slowly. The mixture was maintained under stirring at -60 °C to 0°C for 3 hours and warmed to room temperature overnight. The mixture was filtrated, than the liquid phase was concentrated to give 9.Og of intermediate 58 (yellow oil, yield: 79%).
1HNMR (400 MHz, CDCI3) δ ppm 8.30 (d, 2H), 8.25 (d, 2H), 4.30-4.60 (m, 3H), 3.55 (m, 1 H), 3.1 1 (m, 1 H), 2.29 (m, 1 H), 1.47 (s, 9H), 0.88 (m, 1 H), 0.66 (m, 4H)
Example 32: preparation of intermediate 59: (S)-6-hvdroxymethyl-5-aza- spiro[2.41heptane-5- carboxylic acid tert-butvl ester
(S)-6-(4-Nitro-benzoyloxymethyl)-5-aza-spiro[2.4]heptane-5-carboxylic acid tert- butyl ester (intermediate 58, 8.9g, 23.7mmol) dissolved in 200ml of methanol was cooled to 0°C, then 2N NaOH aqueous (100ml) was added. The mixture was maintained under stirring at room temperature for 1 hour, and then concentrated.
Ethyl acetate (200ml) was added and the organic solvent was washed with water
(200ml) and brine (200ml), dried (Na2SO4) and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate 5/1 ) to give 5.Og of crude product, then purified by preparative HPLC to give 3.25g of intermediate 59 (colorless oil, yield: 62%).
1HNMR (400 MHz, CDCI3) δ ppm 4.73 (m, 1 H), 3.78 (m, 1 H), 3.55 (m, 1 H), 3.33 (m, 1 H), 2.95 (m, 1 H), 2.1 1 (m, 1 H), 1.64 (m, 1 H), 1.40 (s, 9H), 0.53 (m, 4H);
MS Calcd.: 227; MS Found: 228 ([M+1 ]+).
Example 33: preparation of intermediate 60: (S)-tert-butyl 6-formyl-5- azaspiror2.41heptane-5-carboxvlate
To (S)-tert-butyl 6-(hydroxymethyl)-5-azaspiro[2.4]heptane-5-carboxylate
(Intermediate 59, 2.2g, 9.7 mmol) dissolved in 1 OmI of DCM, TEMPO (306mg, 1.9mmol) and BAIB (3.43mg, 10.6mmol) were added. After 2 hours at 250C, the reaction is diluted with DCM (150ml), washed with an aqueous solution of Na2S2O3 then with water, dried (Na2SO4) and evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether to petroleum ether/ethylacetate
95/5). (S)-tert-butyl 6-formyl-5-azaspiro[2.4]heptane-5-carboxylate was obtained as light yellow solid (1.8g).
1HNMR(DMSO-d6) δ ppm 9.52 (s, 1 H) 4.21 (m, 1 H) 3.20-3.40 (m, 2H) 2.1 1 (m, 1 H) 1.50-1.80 (m, 1 H) 1.36-1.41 (m, 9H) 0.50-0.65 (m, 4H)
Example 34 : preparation of intermediate 61 : (S)-tert-butyl 6-(((5-chloropyridin-2- yl)amino)methyl)-5-azaspiro[2.41heptane-5-carboxylate
(S)-tert-butyl 6-formyl-5-azaspiro[2.4]heptane-5-carboxylate (Intermediate 60, 700mg, 3.1 mmol) was dissolved in dichloroethane (15ml), then acetic acid (0.9ml,
15.5mmol) and 5-chloro pyridine (400mg, 3.1 mmol) were added. After 2 hours at room temperature NaBH(OAc)3 (1.05g, 4.97mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with DCM. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; crude product was purified by silica gel column chromatography using Petroleum ether/Ethyl acetate
= 95/5 to 85/15 . (S)-tert-butyl 6-(((5-chloropyridin-2-yl)amino)methyl)-5-
azaspiro[2.4]heptane-5-carboxylate was obtained as colourless oil (600mg). MS (ESI) m/z: 338 [M+H]+
Example 35: preparation of intermediate 62: (S)-tert-butyl 6-(((6-methylpyridin-2- yl)amino)methyl)-5-azaspiro[2.4]heptane-5-carboxylate
(S)-tert-butyl 6-formyl-5-azaspiro[2.4]heptane-5-carboxylate (Intermediate 60, 700mg, 3.1 mmol) was dissolved in dichloroethane (15ml), then acetic acid (0.9ml, 15.5mmol) and 6-methyl pyridine (336mg, 3.1 mmol) were added. After 2 hours at room temperature NaBH(OAc)3 (1.05g, 4.97mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with DCM. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; crude product was purified by silica gel column chromatography using Petroleum ether/Ethyl acetate = 95/5 to 85/15 . (S)-tert-butyl 6-(((6-methylpyridin-2-yl)amino)methyl)-5- azaspiro[2.4]heptane-5-carboxylate was obtained as colourless oil (600mg). Example 36: preparation of intermediate 63:(S)-N-(5-azaspiro[2.4]heptan-6- ylmethyl)-5-chloropyridin-2-amine
(S)-tert-butyl6-(((5-chloropyridin-2-yl)amino)methyl)-5-azaspiro[2.4]heptane-5- carboxylate Intermediate 60, 600mg, 1.77mmol) was dissolved in dichloromethane (10ml) and cooled to 0°C, then trifluoroacetic acid (4ml) was added. After 1 hour at 0°C and 3 hours at room temperature the solution was evaporated, the residue re-
dissolved in dichloromethane was washed with saturated NaHCO
3 aqueous solution. The organic layers were dried (Na
2SO
4) and concentrated under vacuum. The crude was purified by silica gel column chromatography (CHCI
3/MeOH = 8/2). (S)-N-(5-azaspiro[2.4]heptan-6-ylmethyl)-5-chloropyridin-2-amine was obtained as light yellow oil (400mg).
MS (ESI) m/z: 238 [M+H]+
1HNMR(CDCI3) δ ppm 8.02 (d, J=3 Hz,1 H) 7.35(dd, J= 8Hz, 3Hz, 1 H) 6.39 (d, J= 8Hz, 1 H) 5.05 (m, 1 H) 3.60-3.63 (m, 1 H) 3.40-3.48(m, 1 H) 3.20-3.30 (m, 1 H) 2.85-2.90 (m, 1 H) 1.85-1.95 (m, 1 H) 1.52-1.61 (m, 1 H) 0.50-0.60 (m, 4H)
Example 37: preparation of intermediate 64: (S)-N-(5-azaspiro[2.41heptan-6- ylmethyl)-6-methylpyridin-2-amine
S)-tert-butyl 6-(((6-methylpyridin-2-yl)amino)methyl)-5-azaspiro[2.4]heptane-5- carboxylate
(Intermediate 60, 600mg, 1.89mmol) was dissolved in dichloromethane (10ml) and cooled to 0°C, then trifluoroacetic acid (4ml) was added. After 1 hour at 0°C and 3 hours at room temperature the solution was evaporated, the residue re-dissolved in dichloromethane was washed with saturated NaHCO3 aqueous solution. The organic layers were dried (Na2SO4) and concentrated under vacuum. The crude was purified by silica gel column chromatography (CHCI3/MeOH = 8/2). (S)-N-(5- azaspiro[2.4]heptan-6-ylmethyl)-6-methylpyridin-2-amine was obtained as light yellow oil (225mg).
MS (ESI) m/z: 218 [M+H]+ .
1HNMR(CDCI3) δ ppm 7.37-7.41 (m,1 H) 6.55 (d, J= 8Hz, 1 H) 6.45 (d, J= 8Hz, 1 H) 5.62 (s, 1 H) 4.25-4.31 (m, 1 H) 3.76-3.80 (m, 1 H) 3.60-3.66 (m, 1 H) 3.28 (d, J=12Hz, 1 H) 3.07 (d, J= 12Hz, 1 H) 1.89-2.01 (m, 2H) 0.59-0.81 (m, 4H)
Example 38: Preparation of intermediate 65: (S)-tert-butyl 6-((1 ,3-dioxoisoindolin- 2-yl)methyl)-5-azaspiror2.41heptane-5-carboxylate
In a round bottomed flask under nitrogen atmosphere tripenylphosphine (947 mg, 3.61 mmol) and phtalimide (541 mg, 3.67 mmol) were added to a solution of (S)- tert-butyl 6-(hydroxymethyl)-5-azaspiro[2.4]heptane-5-carboxylate (Intermediate 59, 498 mg, 2.19 mmol) in 10 ml of dry THF. The mixture was cooled with an ice bath and a solution of DEAD 40%wt in toluene was dropwise added (1.6 ml, 3.51 mmol).
The reaction was allowed to warm up to room temperature overnight. The next morning the mixture was quenched with a small amount of MeOH; the solvent was then removed and the obtained residue was purified by flash chromatography on a 5Og silica cartridge, eluting with a step gradient: cyclohexane 100% in 2 column volumes, cyclohexane/AcOEt 95/5 in 2 column volumes, linear gradient up to 85/15 in 10 column volumes and then isocratic 85/15 in 4 column volumes.
The collected fractions were then evaporated to give 758 mg of (S)-tert-butyl 6- ((1 ,3-dioxoisoindolin-2-yl)methyl)-5-azaspiro[2.4]heptane-5-carboxylate as a clear oil (yield 97%).
MS (ESI) m/z 357 [M+H]+; 379 [M+Na]+
1HNMR(CDCI3) δ ppm 7.83-7.91 (m,2H) 7.69-7.78 (m, 1 H) 4.29-4.52 (m, 1 H) 4.0- 4.13 (m, 1 H) 3.77-3.87 (m, 1 H) 3.46-3.61 (m, 1 H) 3.09 (m, 1 H) 2.21 -2.31 (m, 1 H) 1.26-1.40 (m, 9H) 0.55-0.89 (m, 4H)
Example 39: Preparation of intermediate 66: (S)-tert-butyl 6-(aminomethyl)-5- azaspiro[2.4]heptane-5-carboxylate
(S)-tert-butyl 6-((1 ,3-dioxoisoindolin-2-yl)methyl)-5-azaspiro[2.4]heptane-5- carboxylate (Intermediate 65, 752 mg, 2.1 1 mmol) was dissolved in 20 ml of ethanol. Hydrazine monohydrate (550 ul, 1 1.32 mmol) was added and the mixture was stirred at room temperature overnight.
Copious amount of a white precipitate formed, which was filtered and washed thoroughly with diethyl ether. The liquid phase was evaporated to dryness and the residue was taken up again in diethyl ether. The resulting suspension was then filtered again, further washing all the solids with ether. All the collected liquid phases were evaporated to give 420 mg of (S)-tert-butyl 6-(aminomethyl)-5- azaspiro[2.4]heptane-5-carboxylate as a clear viscous oil (yield 88%).
MS (ESI) m/z 227 [M+H]+; 249 [M+Na]+
1HNMR(CDCI3) δ ppm 4.38-4.26 (m,1 H) 3.42-3.66 (m, 1 H) 2.87-3.09 (m, 3H) 2.14- 2.19 (m, 1 H) 1.48 (s, 9H) 1.24-1.32 (m, 1 H) 0.58-0.75 (m, 4H)
Example 40: Preparation of intermediate 67: (SHert-butyl 6-(((4,6- dimethylpyrimidin-2-yl)amino)methyl)-5-azaspiror2.41heptane-5-carboxvlate
In a microwave vial (S)-tert-butyl 6-(aminomethyl)-5-azaspiro[2.4]heptane-5- carboxylate (Intermediate 66, 61 mg, 0.27 mmol) and 2-chloro-4,6- dimerhylpyrimidine (61 mg, 0.43 mmol) were dissolved in 1 ml of isopropyl alcohol.
DIPEA (0.1 ml, 0.57 mmol) was added and the vial was sealed and heated to
120°C in two cycles of 30 minutes each by microwave irradiation.
The solvent was then removed and the residue purified by flash chromatography on a 10g silica cartridge, eluting with a step gradient: cyclohexane/AcOEt in 2 column volumes, then linear gradient to 65/35 in 16 column volumes and finally isocratic 65/35 in 3 column volumes.
Removal of the solvent yielded 37 mg of (S)-tert-butyl 6-(((4,6-dimethylpyrimidin-2- yl)amino)methyl)-5-azaspiro[2.4]heptane-5-carboxylate as a clear crust (yield 41 %).
MS (ESI) m/z 333 [M+H]+; 355 [M+Na]+
1HNMR(CDCI3) δ ppm 6.30-6.32 (m,1 H) 5.37-5.72 (m, 1 H) 4.1 1 -4.20 (m, 1 H) 3.60- 3.85 (m, 2H) 3.44-3.58 (m, 1 H) 3.09-3.12 (m, 1 H) 2.30 (s, 6H) 2.14-2.20 (m, 1 H) 1.50 (s, 9H) 0.85-0.95 (m, 1 H) 0.50-0.76 (m, 4H)
Example 41 : Preparation of intermediate 68: (SHert-butyl 6-(((5-chloropyrimidin-2- yl)amino)methyl)-5-azaspiro[2.4]heptane-5-carboxylate
In a microwave vial (S)-tert-butyl 6-(aminomethyl)-5-azaspiro[2.4]heptane-5- carboxylate (Intermediate 66, 66 mg, 0.29 mmol) and 2,5-dichloropyrimidine (65 mg, 0.44) were dissolved in 1 ml of isopropyl alcohol. DIPEA (100 ul, 0.58 mmol) was added; the vial was sealed and heated to 120°C for 20 minutes by microwave irradiation.
The solvent was then removed and the residue purified by flash chromatography on a 10g silica cartridge, eluting with a step gradient: cyclohexane/AcOEt in 2 column volumes, then linear gradient to 80/20 in 10 column volumes and finally isocratic 80/20 in 2 column volumes.
Removal of the solvent yielded 60 mg of (S)-tert-butyl 6-(((5-chloropyrimidin-2- yl)amino)methyl)-5-azaspiro[2.4]heptane-5-carboxylate as a white solid (yield 61 %).
MS (ESI) m/z 339-341 (Cl pattern) [M+H]+; 361 -363 [M+Na]+
1HNMR(CDCI3) δ ppm 8.21 (s,2H) 5.62-6.5 (m, 1 H) 4.20-4.30 (m, 1 H) 3.53-3.62
(m, 2H) 3.07-3.49 (m, 2H) 2.24-2.29 (m, 1 H) 1.61 (m, 1 H) 1.49 (m, 9H) 0.56-0.70
(m, 4H)
Example 42: Preparation of intermediate 69: (S)-N-(5-azaspiro[2.4]heptan-6- ylmethyl)-4,6-dimethylpyrimidin-2-amine
(S)-tert-butyl 6-(((4,6-dimethylpyrimidin-2-yl)amino)methyl)-5- azaspiro[2.4]heptane-5-carboxylate (Intermediate 68, 18 mg, 0.054 mmol) was dissolved in 0.5 ml of dry DCM under nitrogen atmosphere. TFA (0.2 ml) was added and the solution shaken at room temperature for 2 hours.
The reaction mixture was loaded on a 1 g SCX cartridge, which was then washed with MeOH, followed by a solution of ammonia 2.0 M in MeOH. The basic fractions were collected and evaporated to give 9 mg of (S)-N-(5-azaspiro[2.4]heptan-6- ylmethyl)-4,6-dimethylpyrimidin-2-amine as a colourless residue (yield 71 %).
MS (ESI) m/z 233 [M+H]+
1HNMR(CDCI
3) δ ppm 6.32 (s,1 H) 5.36 (m, 1 H) 3.61 -3.67 (m, 2H) 3.41 -3.47 (m, 1 H) 2.89 (m, 2H) 2.30 (s, 6H) 1.83-1.87 (m, 1 H) 1.61 -1.65 (m, 1 H) 0.52-0.63 (m, 4H) Example 43: Preparation of intermediate 70: (S)-N-(5-azaspiro[2.4]heptan-6- ylmethyl)-5-chloropyrimidin-2-amine
(S)-tert-butyl 6-(((5-chloropyrimidin-2-yl)amino)methyl)-5-azaspiro[2.4]heptane-5- carboxylate (Intermediate 68, 59 mg, 0.17 mmol) was dissolved in 1 ml of dry DCM under nitrogen atmosphere. TFA (0.3 ml) was added and the solution shaken at room temperature for 40 minutes.
The reaction mixture was diluted in a small amount of MeOH and loaded on a 1 g SCX cartridge, which was then washed with MeOH, followed by a solution of ammonia 2.0 M in MeOH. The basic fractions were collected and evaporated to give 37 mg of (S)-N-(5-azaspiro[2.4]heptan-6-ylmethyl)-5-chloropyrimidin-2-amine as a white solid (yield 91 %).
MS (ESI) m/z 239-241 (Cl pattern) [M+H]+
1HNMR(CDCI3) δ ppm 8.22 (s,2H) 5.74 (m, 1 H) 3.55-3.67 (m, 2H) 3.35-3.41 (m, 1 H) 2.86-2.92 (m, 2H) 1.84-1.89 (m, 1 H) 1.56-1.61 (m, 1 H) 0.45-0.70 (m, 4H).
Example 44: Preparation of intermediate 71 : tert-butyl 8-azaspiro[4.51decane-8- carboxylate
To a solution of 8-azaspiro[4.5]decane (which has been described in WO 9800404 A1 6.2g, 44.5mmol) in dichloromethane (130ml), which was cooled to 0°C, triethylamine (7.5ml, 53.4mmol) was added then a solution of tert-buthyl dicarbonate (10.68g, 48.9mmol) in dichloromethane (50ml) was added in 20 minutes. The clear solution was maintained under stirring at room temperature for 18 hours, then dichloromethane (50ml) was added and the organic solution was washed with water (2x20ml), HCI 0.1 N (20ml) then water (2x20ml). The organic solvent was anhydrified (Na2SO4) and evaporated to give a crude that was purified on silica gel column (Hexane/AcOEt 95/5) to give 6g of the title compound (light yellow solid).
Example 45: Preparation of intermediate 72: (±)tert-butyl 7-formyl-8- azaspiror4.51decane-8-carboxvlate
tert-butyl 8-azaspiro[4.5]decane-8-carboxylate (Intermediate 71 , 6g, 25.07mmol) dissolved in 150ml of Et2O was cooled to -78°C, then N,N,N',N'-tetramethyl ethylendiamine (9.08ml, 60.16mmol) and secBuLi 1.4M in hexane (42.95ml, 60.16mmol) were added. After 10 minutes at -60 °C, the temperature was raised to
-20 °C for 60 minutes, then the reaction was cooled to -78 °C and dimethylformamide (4.47ml, 60.16mmol, dissolved in 5 ml of Et2O) was added. After 30 minutes a saturated aqueous solution of NH4CI (30ml) was slowly added, then reaction was allowed to reach room temperature. Reaction was extracted with Et2O (3x 100ml), the organic solvent was dried (Na2SO4) and evaporated to obtain 4g of the title compound as yellow oil.
Example 46: Preparation of intermediate 73: (±)tert-butyl 7-(((6-methylpyridin-2- yl)amino)methyl)-8-azaspiror4.51decane-8-carboxylate
(±)tert-butyl 7-formyl-8-azaspiro[4.5]decane-8-carboxylate (Intermediate 72, 2g, 7.48mmol) was dissolved in dichloroethane (25ml), then acetic acid (5 eq) and 2- amino 6 picoline (810mg, 7.48mmol) were added. After 3 hours at room temperature NaBH(OAc)3 (2.53g, 1 1.96mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO3 and extracted with ethylacetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; the crude was then purified by silica gel column chromatography (petroleum ether/ethyl acetate = 9/1 ) to obtain 1.3g of intermediate as colourless oil.
Example 47: Preparation of intermediate 74: (±)tert-butyl 7-(((5-chloropyridin-2- yl)amino)methyl)-8-azaspiror4.51decane-8-carboxvlate
(±)tert-butyl 7-formyl-8-azaspiro[4.5]decane-8-carboxylate (Intermediate 72, 2g, 7.48mmol) was dissolved in dichloroethane (25ml), then acetic acid (5 eq) and 2- amino 5 chloropyridine (961 mg, 7.48mmol) were added. After 3 hours at room temperature NaBH(OAc)
3 (2.53g, 1 1.96mmol) was added and the reaction was maintained under stirring at room temperature for 18 hours. The reaction was poured in aqueous NaHCO
3 and extracted with ethylacetate. The organic layers were combined, dried (Na
2SO
4) and concentrated under vacuum; the crude was purified by silica gel column chromatography (petroleum ether/ethyl acetate = 9/1 ). 1 g of intermediate 74 were obtained as colourless oil.
Example 48: Preparation of intermediate 75: (±)N-(8-azaspiro[4.51decan-7- ylmethyl)-6-methylpyridin-2-amine
(±)tert-butyl 7-(((6-methylpyridin-2-yl)amino)methyl)-8-azaspiro[4.5]decane-8- carboxylate
(intermediate 73, 1.3g, 3.62 mmol) was dissolved in dichloromethane (1 OmI) and cooled to 0°C, then trifluoroacetic acid (30ml) was added. After 1 hour at 0°C and 2 hours at room temperature the solution was evaporated, the residue re-dissolved in dichloromethane was washed with saturated NaHCO3 aqueous solution. The organic layers were dried (Na2SO4) and concentrated under vacuum to obtaine 900mg of the title compound.
MS (ESI) m/z 260 [M+H]+
Example 49: Preparation of intermediate 76: (±)N-(8-azaspiro[4.5]decan-7- ylmethyl)-5-chloropyridin-2-amine
(±)tert-butyl 7-(((5-chloropyridin-2-yl)amino)methyl)-8-azaspiro[4.5]decane-8- carboxylate (intermediate 74, 1 g, 2.63 mmol) was dissolved in dichloromethane (10ml) and cooled to 0°C, then trifluoroacetic acid (30ml) was added. After 1 hour at 0°C and 2 hours at room temperature the solution was evaporated, the residue re-dissolved in dichloromethane was washed with saturated NaHCO
3 aqueous solution. The organic layers were dried (Na
2SO
4) and concentrated under vacuum to obtain Obtained 600mg of the title compound.
MS (ESI) m/z 281 [M+H]+
Preparation of the invention compounds:
Example 50:
Compound 1 : (±) (2-methyl-5-phenylthiazol-4-yl)(5-((6-methylpyridin-2- ylamino)methyl)-6-azaspiro[2.51octan-6-yl)methanone
Intermediate 7 (30 mg, 0.129mmol) ) was dissolved in dichloromethane (2ml), then diisopropyl ethylamine (75μl, 0.427mmol) and O-(benzotriazol-1 -yl)-N,N,N'N'- tetramethyluronium hexafluorophosphate (69mg, 0.18mmol) were added. After 30 minutes at room temperature 2-methyl-5-phenylthiazole-4-carboxylic acid, whose preparation has been described in US 3282927(40mg, 0.18mmol), was dissolved in dichloromethane (2ml) and dimethylformamide (1 ml) and added to the reaction. After 18 hours at room temperature the mixture was poured in aqueous NaHCO3 and extracted with AcOEt. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; the obtained crude was purified by silica gel column chromatography (petroleum ether/ethyl acetate =7/3), thus obtaining 12 mg of compound 1 as white solid.
MS (ESI) m/z 433.1 [M+H]+;; 1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 7.84
(d, 1 H) 7.25-7.64(m, 5H) 6.48 (d, 1 H) 6.1 1 (d, 1 H) 4.95-4.98 (m, 1 H) 3.70-3.85 (m,
1 H) 3.44-3.55 (m, 1 H) 2.95-3.15 (m, 1 H) 2.74 (s, 3H) 2.50 (s, 3H) 1.80-1.95 (m,
1 H) 1.32-1.15 (m, 2H) 0.89-0.80 (m, 2H) 0.57-0.15 (m, 4H).
The enantiomeric mixture of (±) (2-methyl-5-phenylthiazol-4-yl)(5-((6- methylpyridin-2-ylamino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone (compound
1 , 30mg) was separated by chiral preparative HPLC (preparative chromatographic conditions: Method C) to give two enantiomers:
Example 51 :
Compound 2j (2-methyl-5-phenylthiazol-4-yl)(5-((6-methylpyridin-2- ylamino)methyl)-6-azaspiror2.51octan-6-yl)methanone (Isomer A)
HPLC retention time: 36.3 min (10 mg)
Example 52:
Compound 3j (2-methyl-5-phenylthiazol-4-yl)(5-((6-methylpyridin-2- ylamino)methyl)-6-azaspiro[2.51octan-6-yl)methanone (Isomer B)
HPLC retention time: 38.6 min (6 mg)
Example 53:
Compound 4: (±) (5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiror2.51octan-6- yl)(2-methyl-5-phenylthiazol-4-yl)methanone
Intermediate 8 (60 mg, 0.238mmol) was dissolved in dichloromethane (2ml), then diisopropyl ethylamine (137μl, 0.786mmol) and 0-(benzotriazol-1 -yl)-N,N,N'N'- tetramethyluronium hexafluorophosphate (126mg, 0.33mmol) were added. After 30 minutes at room temperature 2-methyl-5-phenylthiazole-4-carboxylic acid (73mg, 0.33mmol) was dissolved in dichloromethane (2ml) and dimethylformamide (1 ml) and added to the reaction. After 18 hours at room temperature the mixture was poured in aqueous NaHCO3 saturated solution and extracted with ethylacetate. The organic layers were combined, dried (Na2SO4) and concentrated
under vacuum; crude product was purified by silica gel column chromatography
(petroleum ether/ethylacetate =1/1 to ethylacetate), thus obtaining 37 mg of compound 4 as white solid.
MS (ESI) m/z 453.1 [M+H]+; 1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 7.92
(s, 1 H) 7.28-7.51 (m, 5H) 6.33 (d, 1 H) 5.57 (m, 1 H) 4.68-4.71 (m, 1 H) 3.89-3.95
(m, 1 H) 3.41 -3.46 (m, 1 H) 3.10-3.25(m, 1 H) 2.90-3.05 (m, 1 H) 2.81 (s, 3H) 1.80-
1.90 (m, 1 H)1.20-1.50(m, 1 H) 0.87 (d, 1 H) 0.70 (d, 2H) 0.35-0.50 (m, 2H) 0.15-
0.30 (m, 2H).
The enantiomeric mixture of (±) (5-((5-chloropyridin-2-ylamino)methyl)-6- azaspiro[2.5]octan-6-yl)(2-methyl-5-phenylthiazol-4-yl)methanone (compound 4,
75 mg) was separated by chiral preparative HPLC (preparative chromatographic conditions:method A) to give two enantiomers:
Example 54:
Compound 5: (5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiro[2.51octan-6-yl)(2- methyl-5-phenylthiazol-4-yl)methanone (Isomer A)
HPLC retention time: 16 min (23mg)
Example 55:
Compound 6: (5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiror2.51octan-6-yl)(2- methyl-5-phenylthiazol-4-yl)methanone (Isomer B)
HPLC retention time: 18 min (26mg)
Example 56:
Compound 7: (±) (2-methyl-5-phenylthiazol-4-yl)(5-((5-(trifluoromethyl)pyridin-2- ylamino)methyl)-6-azaspiror2.51octan-6-yl)methanone
Intermediate 9 (60 mg, 0.210mmol) ) was dissolved in dichloromethane (2ml), diisopropyl ethylamine (121 μl, 0.693mmol) and 0-(benzotriazol-1 -yl)-N,N,N'N'-
tetramethyluronium hexafluorophosphate (1 12mg, 0.294mmol) were added. After 30 minutes at room temperature 2-methyl-5-phenylthiazole-4-carboxylic acid (65mg, 0.294mmol) was dissolved in dichloromethane (2ml) and dimethylformamide (1 ml) and added to the reaction. After 18 hours at room temperature the mixture was poured in aqueous NaHCO3 saturated solution and extracted with ethylacetate. The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; the obtained crude product was purified by silica gel column chromatography (gradient from dichloromethane/Ethyl acetate =1/1 to Ethyl acetate), thus obtaining 15 mg of compound 7 as white solid.
MS (ESI) m/z 509 [M+Na]+. 1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CD3OD) δ ppm 8.05 (s, 1 H) 7.39-7.60 (m, 5H) 6.41 (d, 1 H) 4.65 (m, 1 H) 4.20 (m, 1 H) 3.69-3.76 (m, 1 H) 3.28-3.35 (m, 1 H) 3.10-3.15(m, 1 H) 2.43 (s, 3H) 1.82 (m, 1 H) 1.30-1.45 (m, 1 H) 0.90-1.05 (m, 2H) 0.6-0.68 (m, 1 H) 0.30-0.55 (m, 2H) 0.15-0.25 (m, 2H).
The enantiomeric mixture of (±) (2-methyl-5-phenylthiazol-4-yl)(5-((5- (trifluoromethyl)pyridin-2-ylamino)methyl)-6-azaspiro[2.5]octan-6-yl)methanone (compound 7, 8mg) was separated by chiral preparative HPLC (preparative chromatographic conditions:Method A) to give the pure enantiomer:
Example 57:
Compound 8: (2-methyl-5-phenylthiazol-4-yl)(5-((5-(trifluoromethyl)pyridin-2- ylamino)methyl)-6-azaspiro[2.51octan-6-yl)methanone (single enantiomer)
HPLC retention time: 17.9 min (4mg).
Example 58:
Compound 9: (±) (5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiror2.51octan-6- yl)(2-(cvclopropylmethoxy)phenyl)methanone
Intermediate 8 (50 mg, 0.198mmol) ) was dissolved in dichloromethane (2ml), then diisopropyl ethylamine (1 15μl, 0.65mmol) and O-(benzotriazol-1 -yl)-N,N,N'N'- tetramethyluronium hexafluorophosphate (105mg, 0.277mmol) were added. After 30 minutes at room temperature 2-(cyclopropylmethoxy) benzoic acid, whose preparation has been described in Journal of Medicinal Chemistry (1993), 36(10), 1387-92 (Intermediate 10, 53mg, 0.277mmol) was dissolved in dichloromethane (2ml) and dimethylformamide (1 ml) and added to the reaction. After 18 hours at room temperature the mixture was poured in aqueous NaHCO
3 saturated solution and extracted with ethylacetate. The organic layers were combined, dried (Na
2SO
4) and concentrated under vacuum; the obtained crude product was purified by silica gel column chromatography (gradient Petroleum ether/Ethyl acetate =8/2 to 1/1 ), thus obtaining 12 mg of compound 9 as white solid.
MS (ESI) m/z: 426 [M+H]+ . 1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 8.02 (s, 1 H) 6.75-7.29 (m, 6H) 6.45 (d, 1 H) 5.0-5.32 (m, 2H) 3.75-4.05 (m, 4H) 3.20- 3.50 (m, 1 H) 2-2.40 (m, 2H) 1.1 -1.45 (m, 2H) 0.73-0.76 (m, 1 H) 0.2-0.7 (m, 8H).
Example 59:
Compound 10: (±) (5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiror2.51octan-6- yl)(5-(4-fluorophenyl)-2-methylthiazol-4-yl)methanone
To a solution of hydroxybenzotriazole (12 mg, 0.09 mmole) and 1 -ethyl-3-(3- dimethylaminopropyl)carbodiimide HCI (23 mg, 0.12 mmole) in anhydrous dichloromethane (1.5 ml), 5-(4-fluorophenyl)-2-methylthiazole-4-carboxylic acid (20 mg, 0.08 mmole) was added and the resulting solution was stirred 15 min. (±) N-(6 azaspiro[2.5]octan-5-ylmethyl)-5-chloropyridin-2-amine (Intermediate 8, 20 mg, 0.08 mmole) was added and the mixture stirred for further 3 hours at room temperature. The reaction mixture was diluted with dichloromethane (2ml) and
washed with NaHCO3 saturated solution (3x5 ml). After drying over Na2SO4 and filtration, the organic phase was evaporated under vacuum and the residue was purified by SPE-Si cartridge (5g) eluting with a mixture dichloromethane:MeOH (from dichloromethane to dichloromethane:MeOH 95:5).
39.8 mg of desired compound as mixture 1 :0.57 of conformers were isolated.
MS (ESI); m/z 471 [MH]+
1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 7.9 (d, 1 H) 7.50-7.42 (m, 2H) 7.28-7.25 (dd, 1 H) 7.12-7.09 (t, 1 H) 6.34-6.31 (d, 1 H) 5.65 (m, 1 H) 4.66-4.65 (m, 1 H) 3.96- 3.90 (m, 1 H) 3.21 -3.17 (m, 1 H) 3.01 -2.94 (dt, 1 H) 2.60 (s, 3H) 2.15-2.05 (dd, 1 H) 1.9-1.77 (dt, 1 H) 1.46-1.42 (dd, 1 H) 0.77-.074 (d, 1 H) 0.49-0.39 (m, 2H) 0.25-0.15 (m, 2H).
Example 60:
Compound 11 : (±)(5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiro[2.51octan-6- yl)(5-methyl-2-(2H-1.2.3-triazol-2-yl)phenyl)methanone
To a solution of hydroxybenzotriazole (12.9 mg, 0.095 mmol) and O-(benzotriazol- 1 -yl)-N,N,N'N'-tetramethyluronium hexafluorophosphate HCI (23 mg, 0.12 mmol) in anhydrous dichloromethane (2 ml), 5-methyl-2-(2H-1 ,2,3-triazol-2-yl)benzoic acid (19.4 mg, 0.095 mmole) was added and the resulting solution was stirred for 1 h at room temperature. (±) N-(6 azaspiro[2.5]octan-5-ylmethyl)-5-chloropyridin-2- amine (Intermediate 8, 20 mg, 0.08 mmol) was added and the resulting mixture was stirred at the same temperature overnight. The mixture was washed with NaHCO3 saturated solution (3x5ml).
After drying over Na2SO4 and filtration, the organic phase was evaporated under vacuum and the residue was purified by SPE-Si cartridge (2g) eluting with a
mixture dichloromethane:MeOH (from dichloromethane to dichloromethane:MeOH 98:2).
29 mg of the desired compound as mixture of conformers were isolated.
MS (ESI); m/z 436 [MH]+
1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 8.08-8.07 (d, 1 H) 7.95-7.92 (m, 1 H) 7.85- 7.79 (m, 2H) 7.7 (s, 2H) 7.35-7.33 (d, 1 H) 6.40-6.38 (d, 1 H) 5.61 -5.60 (d, 1 H) 5.21 - 5.14 (m, 1 H) 3.90-3.84 (m, 1 H) 3.66-3.59 (m, 1 H) 3.41 -3.32 (m, 1 H) 3.11 -3.01 (m, 1 H) 2.45 (s, 3H) 2.29-2.21 (dd, 1 H) 1.99-1.85 (m, 1 H) 1.19-1.16 (d, 1 H) 0.75-0.68 (d, 1 H) 0.58-0.27 (m, 4H)
Example 61 :
Compound 12: (±)(5-((5-chloropyridin-2-ylamino)methyl)-6-azaspiro[2.51octan-6- yl)(5-methyl-2-(pyrimidin-2-yl)phenyl)methanone
To a solution of hydroxybenzotriazole (13 mg, 0.095 mmol) and 0-(benzotriazol-1 - yl)-N,N,N'N'-tetramethyluronium hexafluorophosphate HCI (23 mg, 0.12 mmol) in anhydrous dichloromethane (2 ml), 5-methyl-2-(pyrimidin-2-yl)benzoic acid (20.4 mg, 0.095 mmole) was added and the resulting solution was stirred 1 h at room temperature. (±) N-(6 azaspiro^.Sloctan-S-ylmethylJ-S-chloropyridin^-amine (Intermediate 8, 20 mg, 0.08 mmol) was added and the resulting mixture was stirred at the same temperature overnight. The reaction mixture was washed with NaHCO3 saturated solution (3x5ml). After drying over Na2SO4 and filtration, the organic phase was evaporated under vacuum and purified by SPE-Si cartridge (2g) eluting with a mixture dichloromethane:MeOH (from dichlorometane to dichloromethane:MeOH 98:2).
10 mg of the desired compound as mixture of conformers were isolated.
MS (ESI); m/z 446 [MH]+
1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 8.80-8.77 (m, 1 H) 8.64-8.6 (d, 1 H) 8.36- 8.31 (d, 1 H) 8.08-8.04 (m, 1 H) 7.43-7.17 (m, 3H) 7.08-7.03 (t,1 H) 6.36-6.31 (d, 1 H) 5.79 (bs, 1 H) 5.19-5.1 1 (m, 1 H) 4.00-3.89 (m, 1 H) 3.71 -3.62 (m, 1 H) 3.50-3.39 (m, 1 H) 3.37-3.21 (m, 1 H) 2.45 (s, 3H) 2.31 -2.24 (dd, 1 H) 1.99-1.88 (dt, 1 H) 1.25- 1.19 (d, 1 H) 0.75-0.68 (d, 1 H) 0.60-0.13 (m, 4H). The enantiomeric mixture of (±)(5-((5-chloropyridin-2-ylamino)methyl)-6- azaspiro[2.5]octan-6-yl)(5-methyl-2-(pyrimidin-2-yl)phenyl)methanone (compound 12, 550 mg) was separated by chiral preparative HPLC (preparative chromatographic conditions: method B) to give the single enantiomer (Compounds 13):
Example 62:
Compound 13: (S)-(5-(((5-chloropyridin-2-yl)amino)methyl)-6-azaspiror2.51octan-6- yl)(5-methyl-2-(pyrimidin-2-yl)phenyl)methanone (Isomer A) HPLC retention time: 9 min (150 mg)
Alternatively Compound 13 was obtained by the following procedure: 5-methyl-2- (pyrimidin-2-yl)benzoic acid (428mg, 2mmol; prepared according to WO 2008147518), intermediate 34 (500mg, 2mmol) and DIPEA (0.65ml) were dissolved in DCM (5ml) at 0°C, then T3P (50% in DCM, 1.5g) was added. The mixture is stirred at reflux for 8 hours then at RT overnight. The reaction was washed with NaOH 1 M and water, dried (Na2SO4) and evaporated. The crude was
purified by silica gel column chromatography (DCM to DCIWMeOH = 95/05). 180mg of the desired compound were isolated.
MS (ESI); m/z 446 [MH]+
1HNMR [the product is present as a mixture of conformers. The assignment refers to the major component] (CDCI3) δ ppm 8.80-8.77 (m, 1 H) 8.64-8.6 (d, 1 H) 8.36- 8.31 (d, 1 H) 8.08-8.04 (m, 1 H) 7.43-7.17 (m, 3H) 7.08-7.03 (t,1 H) 6.36-6.31 (d, 1 H) 5.79 (bs, 1 H) 5.19-5.1 1 (m, 1 H) 4.00-3.89 (m, 1 H) 3.71 -3.62 (m, 1 H) 3.50-3.39 (m, 1 H) 3.37-3.21 (m, 1 H) 2.45 (s, 3H) 2.31 -2.24 (dd, 1 H) 1.99-1.88 (dt, 1 H) 1.25- 1.19 (d, 1 H) 0.75-0.68 (d, 1 H) 0.60-0.13 (m, 4H).
Example 64:
Compound 15: (±) methyl 5-chloro-2-((6-(5-(4-fluorophenyl)-2-methylthiazole-4- carbonyl)-6-azaspiro[2.51octan-5-yl)methylamino)benzoate
To a solution of hydroxybenzotriazole (13 mg, 0.097 mmol) and O-(benzotriazol-1 - yl)-N,N,N'N'-tetramethyluronium hexafluorophosphate HCI (23 mg, 0.12 mmol) in anhydrous dichloromethane (2 ml), 5-(4-fluorophenyl)-2-methylthiazole-4- carboxylic acid (23 mg, 0.097 mmole) was added and the resulting solution was stirred 1 h at room temperature. (±) methyl 2-(6-azaspiro[2.5]octan-5- ylmethylamino)-5-chlorobenzoate (intermediate 10) (20 mg, 0.08 mmol) was added and the resulting mixture was stirred at the same temperature overnight. The mixture was washed with NaHCO3 saturated solution (3x5ml).
After drying over Na2SO4 and filtration, the organic phase was evaporated under vacuum and purified by SPE-Si cartridge (2g) eluting with a mixture dichloromethane:MeOH (from dichloromethane to dichloromethane:MeOH 98:2). 35 mg of the desired compound were isolated.
MS (ESI); m/z 528 [MH]+
Examples 64-87 : preparation of compounds 16-35, 3739
In the above formula, Ar
1 is Q and Ar
2 is R in Formula (Via).
General procedure 6
Ar2-COOH (1 eq; prepared according to WO 2008147518 for compounds 19, 20, 26-35, 37-39 and according to US 3282927 for compounds 16, 17, 18, 21 -25), HOBT (1 eq) and EDCI. HCI (1.5eq) dissolved in dichloromethane (5ml/mmol) were stirred at 25 °C for 0.5-2hours, then intermediates 34-45 dissolved in dichloromethane were added. After 18 hours the mixture was poured in an aqueous saturated solution of NaHCO3 and extracted with dichloromethane. The crude was purified by silica gel column chromatography (DCM to DCIWMeOH = 9/1 )
General procedure 7
Ar2-COOH (1 eq; prepared according to WO 2008147518 for compounds 19, 20, 26-39 and according to US 3282927 for compounds 16, 17, 18, 21 -25), intermediates 34-45 (1 eq) and DIPEA (2eq) were dissolved in dichloromethane (5ml/mmol) at 0°C, then T3P (50% in dichloromethane, 1.2 eq) was added. The mixture is stirred at reflux for 3-5 hours then at RT overnight. The reaction was washed with NaOH 1 M and water, dried (Na2SO4) and evaporated. The crude was purified by silica gel column chromatography (DCM to DCM/MeOH = 9/1 ). The enantiomeric purity was calculated as enantiomeric eccess (ee%) by chiral HPLC methods.
According to general procedure 6 or 7 the following compounds were prepared:
Compounds 16-39 characterization:
D
441
451 m/z 447 451
* Compounds were further purified by chiral HPLC to obtain enantiomeric pure products Examples 87-93: preparation of compounds 40 - 46
In the above formula, Ar1 is Q and the group phenyl substituted with R1, R2, Ar2 is R in formula (Via).
General procedure 8
Intermediates 46-50 (1 eq) was dissolved dry DMF (20ml/mmol), then CsF (2 eq), CuI (0.2 eq), [Ph3P]4Pd (0.1 eq) and the corresponding Ar2-tributylstannane (1.5 eq; prepared according to Eur. J. Org. Chem. 2003, 171 1 -1721 ) were added. The mixture was warmed at 130°C for 10 minutes (microwave), then poured in aqueous saturated solution of NH4CI and extracted with AcOEt . The organic layers were combined, dried (Na2SO4) and concentrated under vacuum; crude product was purified by silica gel column chromatography (DCM to DCM/MeOH 9/1 ). The enantiomeric purity was calculated as enantiomeric eccess (ee%) by chiral HPLC methods.
According to general procedure 8 the following compounds were prepared:
Compounds 40-46 characterization:
* Compounds were further purified by chiral HPLC to obtain enantiomeric pure products Example 89-95: preparation of compounds 47 - 53
In the above formula, Ar1 is Q and Ar2 is R in Formula (Via).
General procedure 9
Ar2-COOH (1 eq; prepared according to WO 2008147518 for compounds 49-51 ), HOBT (1 eq) and EDCI. HCI (1.5eq) dissolved in dichloromethane (5ml/mmol) were stirred at 25 °C for 0.5-2hours, then intermediates 67-68 dissolved in dichloromethane were added. After 18 hours the mixture was poured in an
aqueous saturated solution of NaHCO3 and extracted with dichloromethane. The crude was purified by silica gel column chromatography (DCM to DCIWMeOH = 9/1 )
General procedure 10
Ar2-COOH (1 eq; prepared according to WO 2008147518 for compounds 49-51 and according to US 3282927 for compounds 47-48), intermediates 67-68 (1 eq) and DIPEA (2eq) were dissolved in dichloromethane (5ml/mmol) at 0°C, then T3P (50% in DCM, 1.2 eq) was added. The mixture is stirred at reflux for 3-5 hours then at RT overnight. The reaction was washed with NaOH 1 M and water, dried (Na2SO4) and evaporated. The crude was purified by silica gel column chromatography (DCM to DCM/MeOH = 9/1 ).
The enantiomeric purity of all the compounds was calculated as enantiomeric eccess (ee%) by chiral HPLC methods.
According to general procedure 9, or 10 the following compounds were prepared:
Compounds 47-53 characterization:
Example 96:
Compound 54: (±)(2-methyl-5-phenylthiazol-4-yl)(7-(((6-methylpyridin-2- yl)amino)methyl)-8-azaspiror4.51decan-8-yl)methanone
2-methyl-5-phenylthiazole-4-carboxylic acid, whose preparation has been described in US 3282927(85mg, 0.38mmol),HOBT (52mg, 0.38mmol) and EDCI. HCI (1 10mg, 0.578mmol) dissolved in dichloromethane (5ml) were stirred at 25°C for 0.5-2hours, then intermediate 75 (100mg, 0.38mmol) dissolved in dichloromethane (5ml) was added. After 18 hours the mixture was poured in an aqueous saturated solution of NaHCO3 and extracted with dichloromethane. The crude was purified by silica gel column chromatography (DCM to DCIWMeOH = 9/1 ). Yield 36mg of the title compound.
MS (ESI) m/z 461 [M+H]+; 1HNMR(CDCI3) δ ppm 7.20-7.51 (m, 6H) 6.02-6.46 (m, 2H) 4.63-5.07 (m, 1 H) 3.60-3.97 (m, 1 H) 3.25-3.51 (m, 2H) 2.83-3.07 (m, 1 H) 2.61 -2.74 (m, 3H) 2.34-2.39 (m, 3H) 1.76-1.11 (m, 12H) 0.71 -0.92 (m, 1 H).
Example 97:
Compound 55: (±)(7-(((5-chloropyridin-2-yl)amino)methyl)-8-azaspiror4.51decan-8- yl)(2-methyl-5-phenylthiazol-4-yl)methanone
2-methyl-5-phenylthiazole-4-carboxylic acid, whose preparation has been described in US 3282927(78mg, 0.35mmol),HOBT (48mg, 0.35mmol) and EDCI. HCI (102mg, 0.53mmol) dissolved in dichloromethane (5ml) were stirred at 25°C for 0.5-2hours, then intermediate 76 (100mg, 0.38mmol) dissolved in dichloromethane (5ml) was added. After 18 hours the mixture was poured in an aqueous saturated solution of NaHCO3 and extracted with dichloromethane. The crude was purified by silica gel column chromatography (DCM to DCIWMeOH = 9/1 ). Yield 52mg of the title compound.
MS (ESI) m/z 503 [M+Na]+;; 1HNMR(CDCI3) δ ppm 7.91 -8.03(m, 1 H) 7.23-7.49 (m, 6H) 6.29-6.41 (m, 1 H) 5.32-5.44 (m, 1 H) 4.62-5.01 (m, 1 H) 3.75-3.95 (m, 1 H) 3.36-3.63 (m, 1 H) 3.32-3.25 (m, 1 H) 2.82-3.20 (m, 1 H) 2.61 -2.74 (m, 3H), 1.11 - 1.89 (m, 12H), 0.76-0.95 (m, 1 H). Example 98
Evaluation of the effects of the invention compounds
The utility of compounds according to the present invention as antagonists of the orexin 1 (OX1 ) receptor has been determined by methodologies well known to those skilled in the art, including the "FLIPR" measurement of the intracellular calcium levels, [Ca2+]i (D. Smart, J. C. Jerman, S.J. Brough, S. L. Rushton, P. R. Murdock, F. Jewitt, N. A. Elshourbagy, CE. Ellis, D.N. Middlemiss & F. Brown; British Journal of Pharmacology (1999) 128, 1 -3).
In a typical experiment, the antagonistic activity against human OX1 and OX2 receptors is determined by using CHO e HEK-293 cells transfected with human recombinant OX1 and OX2 receptors respectively, seeded at density of 2 and 3x104 cells/well respectively in a 96 fluorometry well plate. Thus the plate was loaded with the calcium dye (Fluo-4NW/probenecid in HBSS, Hepes 20 mM, pH
7,4; Invitrogen) at 37°C for 60 min. Afterward the temperature was equilibrated at 22 °C for 15 min and the [Ca2+]i measured directly on the plate by using a fluorescent plate reader (CelILux Perkin Elmer).
Invention compounds 1 -1 1 were dissolved in DMSO, diluted in HBSS (DMSO, 0.3% final) and added to the wells. In this assay 5 other compounds, with similar substituent structure with respect to the invention compounds but without the spiro ring, have been tested for comparison. After 5 min CHO cells were activated with orexin-A, 3 nM while HEK-293 cells were activated with orexin-B, 10 nM.
The compounds, dissolved in DMSO and diluted in the medium (DMSO, 0.3% final), have been analysed in the 1 nM-1 μM concentration range (every concentration in duplicate). The antagonistic activity has been expressed as pKb (co-logarithm of the apparent dissociation constant calculated by using the modified Cheng Prusoff equation).
Compounds of the following example tested according to this example gave pKbs as follows:
Compound pKb 0X1 pKb 0X2
1 6.8 <5.0
2 8.2 <5.0
3 7.4 NA
44 77..66 NA
5 7.9 <6.0
6 6.8 NA
7 7.6 <5.0
8 7.7 <5.0
99 77..00 <5.0
10 7.4 NA
11 7.5 NA
12 7.3 NA
13 7.6 NA
1155 66..99 <5.0
16 7.2 NA
17 7.5 <5.0
18 7.3 <5.0
19 6.9 NA
2200 77..33 NA
21 6.9 NA
22 7.7 <5.0
23 7.3 NA
24 7.0 NA
25 7.4 NA
26 7.6 NA
27 7.9 NA
28 7.6 NA
29 7.5 NA
30 7.2 NA
31 7.8 NA
32 7.2 NA
33 8.8 NA
34 7.7 NA
35 8.3 7.1
37 6.8 <5.0
38 7.7 NA
39 7.9 <5.0
40 7.5 NA
41 7.2 NA
42 7.6 NA
43 8.0 NA
44 7.8 NA
45 8.0 NA
46 6.8 NA
49 8.1 <5.0
50 7.1 <5.0
51 8.2 <5.0
54 7.2 <4.0
55 7.4 <4.0 comparison 1 6.9 7.5 comparison 2 8.0 7.6 comparison 3 9.0 8.5 comparison 4 8.5 6.8 comparison 5 8.5 8.4
Structure of comparison compouds:
Cmp#5 Cmp#4 Cmp#3 Cmp#2 Cmp#1
NA: IC5O vale not calculable. The concentration-response curve showed less than 25% of the effect at the highest concentration tested.
<5.0 o <6.0: IC5O value above the highest concentration tested. The concentration- response curve showed less than 50% of the effect at the highest concentration tested.
As shown in the table, compounds of the invention resulted surprisingly selective against the 0X1 receptor, differently from the comparison compounds which showed antagonist activity against both OX1 and OX2 receptors.
Specifically compound 2, which had a structure almost identical to comparison compound 2 apart from the spiro ring, resulted highly selective against the OX1 receptor. The same behaviour was seen between compound 1 and comparison compound 3, compound 7 and comparison compound 4 and compound 8 and comparison compound 5.
Example 99
The pharmacokinetics of compound 4 were studied in male Han Wistar rats. The rats were treated intravenously and orally (n=3 for each dose route) with a compound 2 solution at the dose of 1 mg/kg, formulated in Lactic acid 150 mM pH 4.5 in water, 5% DMSO, 10% TWEEN 80. The rats were fitted with a jugular cannula for serial sampling, a full profile was acquired for each rat. Another group of rats (n=3) was treated intravenously and sacrificed after 1 hour harvesting arterial blood and brain to asses brain penetration. Plasma and brain extracts were quantitatively analyzed using a specific and sensitive LC-MS/MS bioanalytical method. Inter-individual variations between the three rats in each group were limited (CV for pharmacokinetic parameters was below 30%).
After intravenous injection, the compound was available to the systemic circulation with average AUC values of about 740 ng.h/mL. Average values for clearance was about 320 ml/h representing 40% of rat liver blood flow that suggested moderate clearance and liver extraction. The average volume of distribution (Vss) was of
330 ml, that was twice the rat total body water, suggesting moderate compound distribution outside of the blood compartment.
After oral administration, absorption was quite fast with a clear maximum concentration reached by 30 minutes for all three animals. The average AUC was about 360 ng.h/mL representing about 50% of AUC after intravenous administration.
One hour after intravenous administration, average arterial plasmatic level was 126 ng/mL, average total brain level was 83 ng/g. Brain/plasma concentrations ratio resulted 0.66 indicating significant brain penetration of the compound.
In conclusion, compound 2 administered to rats at 1 mg/kg resulted a moderate clearance drug with moderate volume of distribution with good brain penetration characteristics. Administered as an oral solution, compound 2 presented a good absolute oral bioavailability of 50%.