[1,2,3]-triazolo[4,5-d] pyrimidine compounds

A compound of formula (I):

• wherein:
• R1 is OR5 or CH2R6;
• R2 is alkyl C1-6 or haloalkyl C1-6;
• R3 is cycloalkyl C3-6, optionally substituted by R7;
• R4 is alkyl C1-6;
• R5 is H or alkyl C1-6, optionally substituted by OH;
• R6 is OH, N3, or NHR8;
• R7 is phenyl, optionally substituted by one or more groups selected from alkyl C1-6, halogen, and OR10;
• R8 is H, alkyl C1-6, or COR9;
• R9 is alkyl C1-6;
• R10 is alkyl C1-6;
• or a pharmaceutically acceptable salt or solvate thereof,
• or a solvate of such a salt.