Cyclic urea compounds and preparation thereof

1. Cyclic urea compounds comprising a ring of at least 7 atoms, said cycle comprising at least one carboxylic amide function and at least one urea function, each amide and urea function being separated from the closest adjacent amide or urea function by at least one methylenic carbon atom.

2. The cyclic urea compounds of claim 1 , of formula (Ia):

in which the R 1 , R 2 , R 3 , R 4 , and R 5 groups can each and independently from one another represent:

a) a hydrogen;

b) a halogen;

c) the protected or non-protected side chain of an amino acid chosen from the natural or non-natural amino acids;

d) a linear or branched alkyl (C1–C20) group, non-substituted or substituted by one or more substituents which include: —COOR a , —CONHR a , —OR a , —NHR a , —NH(CO)R a , —NHCOOR a , an aryl or heteroaryl group, whose cyclic structure contains from 5–20 carbon atoms, one halogen atom, and one R′″CO— group, the R′″ group comprising from 1 to 10 carbon atoms, a nitrile, guanidino or nitro group;

e) one aryl group whose ring structure contains from 5 to 20 carbon atoms, substituted or non-substituted by the above-mentioned substituents, and by cyano or amidine groups;

f) an alkenyl or alkynyl group (C1–C6);

g) a sulfonyl group (R c SO 2 );

h) an acyl group (R c CO);

i) an OR b group;

j) an NH 2 group;

k) —COOR b ;

l) —CONHR b ;

m) —CH 2 CONH 2 ;

R a and R b representing, independently from one another, a hydrogen, an allyl, benzyl, t-butyl, fluorenylmethyl, benzyloxymethyl, tert-butyldimethylsilyl, 2-ethoxyethyl, methoxymethyl, 2-methoxyethoxymethyl, tetrahydropyran-2-yl, trhnethylsilyl, triethylsilyl, 2-(trimethylsilyl)ethyl, trityl, 2,2,2-trichioroethyl, tosyl, ortho-(or para)-nitrophenylsulfonyl, alkyl group having from 1 to 20 carbon atoms, or an aryl group whose ring structure contains from 5–20 carbon atoms;

R c representing an alkyl group having from 1 to 20 carbon atoms, or an aryl group whose ring structure contains from 5–20 carbon atoms, or a heteroaryl, arylalkyl or heteroarylalkyl group;

the R 1 , R 2 , R 3 and R 4 groups also being able to form the following intramolecular cyclizations:

1/cyclization between R 1 and R 2 and/or;

2/cyclization between R 3 and R 4 ;

said cyclic urea compounds able to be, when one or more asymmetric carbons are present in formula (Ia), independently, either of R configuration (rectus) or of S configuration (sinister).

3. The cyclic urea compounds of claim 2 , corresponding to formulae (Ib), (Ic), (Id), (Ie), (If), (Ig), (Ih):

wherein the R1 and R2 groups also being capable of forming an intramolecular cyclization,

said cyclic urea compounds able to be, when one or more asymmetric carbons are present in formulae (Ib) to (Ih), independently, either of R configuration (rectus) or of S configuration (sinister).