Thiobenzophenone synth

Hello fellow chemist and welcome back for a new smelly adventure

Today i wanted to share a synth i just finished that gave a beautiful result: Thiobenzophenone

Little reminder: H2S is a silent killer, keep in mind it is nearly as toxic as HCN and it paralize your odor sensor over time, not smelling it doesn't mean it isn't here, alwaus keep some lead acetate test around of your apparatus and work in a well ventilated area under a air aspiration
For thiobenzophenone i haven't found much info so consider it not less dangerous than benzophenone itself if more

While getting lost on internet at work i found a protocol making it and as it was described as a bleu to purple compound i decided to give a try to the synth
The original procedure is from this site
http://orgsyn.org/demo.aspx?prep=cv4p0927
here my goal is to share the modifications i added to make it more doable by a amateur chemist

-I first started by measuring 25g of benzophenone i put in 125ml of dry ethanol (dry ethanol isn't needed, it is just cheap for me to get it)
-i then setup 2 generators
-The first one was an HCl gas made from NaCl and H2SO4 and the second one was the rest of my iron sulfide H2S generator when i made trithioacetone (i then switched it to a paraffin and sulfur generator as it work better for long periods of time)
- I cooled the flask to 10°c or so and started to bubble both gas in it via only one bubbler. There wasn't much change at the beginning, only slightly turned yellow
- i let it run for a few more dozen minutes and when i came back the whole reaction mixture turned a beautiful deep purple blue color. At this time it was getting late so i stopped the synth and let it in the fridge overnight
-Next day i continued to bubble both for a total of 2h and then i switched to H2S for around 5h. The solution got a deeper and deeper color until some blue cyrstals (looking like copper sulfate) started to precipitate
- At this point i was super happy and decided to stop here after i cooled it one last time to harvest as much product as possible. I filtered under vacuum in ambiant atmosphere and then immediatly put it in my dessicator under nearly perfect vacuum.

I haven't tested it yet or weight it but i would say i got around 15g from eye estimation. I will try to post news about the purity of it by IR spectrum and melting point in the followling week once school start back and that i can use their equipment

The product is described at not very air stable so i will run a test over some days to see if it does decompose

By the way beware, this compoun look beautiful but stink like H2S if not stronger

To finish i still have a deep blue solution where i will try to bubble more H2S to get as much product as possible


Here are some pictures, first of the final product drying unde vacuum second after some hours of H2S bubbling where you can still see benzophenone floating around and finally of the mixture after bubbling H2S and HCl gas at the beginning
Last picture is the ghetto setup i used for bubbling the H2S and cooling the mixture

Anyway hope you enjoyed and see you soon !

I love the blue, an organic blue

Much more impressive than indigo or its dibromo analogue purpur.

I wonder how it would perform as a pigment? Probably not well, but what would its benzhydrol analogue be in color?
Could you check on a little bit with a pinch of borohydride?

Quote: Originally posted by karlos³

I love the blue, an organic blue Much more impressive than indigo or its dibromo analogue purpur. I wonder how it would perform as a pigment? Probably not well, but what would its benzhydrol analogue be in color? Could you check on a little bit with a pinch of borohydride?

Sorry stupid me, I just intended to skim through the thread and then saw the color and reacted like a magpie... without actually knowing what I was talking about

I had actually thought about a benzophenone analogue with 2-thiophene groups instead of, well, a thioketone... insert the blushing smiley we don't have here....
Sorry, the color, and me not reading, I'll keep my mouth shut

I actually made two aminoketones from 2-propanoylthiophene and thats probably why I thought about a 2-thiophenylketone instead of a thioketone...

[Edited on 28-8-2021 by karlos³]

Quote: Originally posted by Ormarion

Little reminder: H2S is a silent killer, keep in mind it is nearly as toxic as HCN and it paralyze your odor sensor over time, not smelling it doesn't mean it isn't here, always keep some lead acetate test around of your apparatus and work in a well ventilated area under a air aspiration