Why do I receive the message "Parse error: unexpected symbol ´int' " in the "public int y;" line ?

using UnityEngine;
using System.Collections;

public class GridItem : MonoBehaviour
{
	public int x;
	{
		get;
		private set;
	}

	public int y;
	{
		get;
		private set;
	}

	public void OnItemPositionChanged (int nexX, int newY;)
	{
		x = newX;
		y = newY;
		gameObject.name = string.format ("Sprite [{0}][{1}]", x, y);
	}

	void OnMouseDown ()
	{
		print ("Click sobre esse item");
	}
}

Seems like you’re completely new to c#, a lot of problems in your code, here is a corrected version for you:

using UnityEngine;
using System.Collections;

public class GridItem : MonoBehaviour
{
    public int x
    { 
        get; 
        private set; 
    }
    public int y
    {
        get;
        private set;
    }
    public void OnItemPositionChanged(int newX, int newY)
    {
        x = newX;
        y = newY;
        gameObject.name = string.Format("Sprite [{0}][{1}]", x, y);
    }
    void OnMouseDown()
    {
        print("Click sobre esse item");
    }
}

You should really consider to start off with some tutorials and examples.

Because properties are defined by their blocks, whereas variables stand alone and are ended with a semicolon. Basically, the semicolon says “I’m done with this” and it’s trying to figure out what to do with the blocks that follow. Remove the semicolon and it should work.