The invention relates to compound of the formula Iin which the substituents are as defined in the specification in free form or in salt form to its preparation, to its use as medicament and to medicaments comprising it.本發明係關於式I化合物:其中取代基如本說明書中所定義;其係呈游離形式或呈鹽形式;其製備、其作為藥物之用途及包含其之藥物。