If anyone can provide advice to a friendship problem?

my friend and i recently decided to end our friendship and go in different directions. we used to spend a lot of time together, we liked hanging out and had the same interests, i suppose naturally as we got older our common interests as well as our daily lives spread further apart and year by year we did less and less to the point of since last summer the only thing we did on a weekly basis was get lunch at a restaurant we never ate at before. over the years as we grew further apart, we discussed simply ending the friendship to make it easier for one another so we wouldn't have to stay aboard a sinking ship so to say but decided against it each time, basically the same reasons for not ending the friendship, our long history together(friends since 1993)growing up together and being there during personal hardships, injuries and illnesses. since about 2007 my friend has been hanging out with a group of people who i don't like at all. i gave them a year to see if there attitudes would change and if i would get more comfortable hanging around them, but i saw that this wasn't the group i wanted to be associated with. i told my friend that i don't think he should be around people like this, high school dropouts with piercing's, tattoos, smoking and drinking. they commonly hung out at a park or bowling alley(not exactly high society)my friend grew up in a troubled home and was always kind of shy and embarrassed about his life. he was never popular but these people were a couple of years younger than him so he enjoyed being liked by any group of people, i told him that this was bad judgement and if he liked me as a longtime friend and trusted my opinion, that he listen to my advice and stay away from them, as i thought they were bad news. he told me not to tell him what to do and how to live his life, it was like this for the past 3 years, i gave him multiple chances to stay away from them before i lost patience because he was ungrateful towards me and everything i had done for him over the years, helping him with stuff thru life. this is when we agreed to go our separate ways, i didn't like that he was hanging out with them, he didn't like to what he perceived as me trying to run his life. there is nobody in his immediate family i can talk to about this situation. i didn't like the person he was when we hung out the past year or two because of the bad influence these people have been on him but i also don't like it that we wont be friends anymore and wont speak. what should i do and is there a way to solve this problem from both ends? any advice is appreciated, and you are welcome to email me if you need more details and information. thanks so much.