The Bible tells us that Israel (Jacob) loved his son Joseph best as he was his child of old age. Although this chapter doesn't say it I wonder if it had anything to do with Rachel being his mother and this was Israel's first and true love. Remember she is no longer alive. Israel worked 14 years for her hand in marriage. She was not blessed with as many children as Leah or the handmaidens and she died giving birth to Benjamin. I am sure all this played a part in Israel's mind as he beheld Joseph. He gave him the position of assistant at the age of 17 and asked him to report back on his brother's behavior. He would bring back nasty tales of their misbehavior. This could not have endeared him to his brothers, nor did the special coat Israel had made for him with many colors. Another thing that really irked his brothers was the dreams he would have. When he would relate them to his brothers, I can picture them rolling their eyes and asking "Who does he think he is?" because the dreams would depict him having a higher station in life than them.
The brothers were out in the field tending the flocks, when Israel sent him to Shechem to check on his them. While he was traveling out to see them they were plotting his death. One brother, Reuben pretended to go along with the plan, but only agreed partially. The brothers wanted to kill him then cast him in a well. Rueben asked them to only toss him in the well but not to cause him direct harm. He secretly planned to return and rescue him after to return to his father. When he arrived the brothers pounced on him removing the coat of many colors. Then they placed him in the well.
The brothers sat down to eat and saw from afar some Ismaelites coming. Greed over took them or perhaps they did not truly want their brother to die, but to be removed from their lives; so they sold him as a slave for 20 pieces of silver; dipped his coat into goat blood and planned to tell their father he had been murdered by an animal. Reuben, who had not been with them at the time, came and checked the well to pull him out and he was gone. Reuben questioned his brothers regarding his brother's disappearance. Then the other brothers presented the bloodied tunic to Israel and asked him if it was Joseph's. Their father went into deep mourning and was unconsolable for many days.
Joseph was again sold, this time to Potiphar in Egypt. Potiphar held a high position under the pharoah.