。
I can't remember his name.
Literal
I [topic-は] his [possessive-の] name [object-を] recall-can-not.
思い出す ('to recall, recollect') + potential → 思い出せる + negative → 思い出せない. 名 is the shortened/literary form of 名前 ('name'). The use of 名 alone gives the sentence a slightly formal or literary flavor.