General Disinterest:
* Apathy: A lack of feeling or emotion; indifference.
* Indifference: Lack of interest, concern, or enthusiasm.
* Uninterested: Not interested or enthusiastic.
* Bored: Feeling weary and lacking interest.
* Unengaged: Not involved or interested in something.
More Specific Types of Disinterest:
* Alienation: Feeling isolated and disconnected from others or society.
* Distraction: Having one's attention diverted from something.
* Disdain: Feeling contempt or disapproval.
* Contempt: Feeling that something is worthless or undeserving of respect.
* Aversion: A strong dislike or avoidance.
The best word to use will depend on the context of your sentence.