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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Skay on April 21, 2021, 02:48:52 AM

Title: Type of reaction unknown
Post by: Skay on April 21, 2021, 02:48:52 AM
What type of reaction mechanism are happening and why?

https://ibb.co/LYHSz4F
Title: Re: Type of reaction unknown
Post by: Borek on April 21, 2021, 04:47:57 AM
Please read the forum rules (https://www.chemicalforums.com/index.php?topic=65859.0).

You have to show your efforts and attempts at answering the problem to receive help, this is a forum policy.
Title: Re: Type of reaction unknown
Post by: Skay on April 21, 2021, 07:13:11 AM
So for the first reaction I discovered it was a Fischer esterification.
The second one is a substitution.
but the third one im not completely sure:

In this reaction we have a substitution that involves the nucleophilic substitution of the Cl as leaving group with the new molecule as nucleophile, using the H for creating HCl as a side product. 
We are using K2CO3 (potassium carbonate) that will be CO3-2 as base for counter the HCl, DMF as a polar aprotic solvent and temperature (90C) all of them for forcing the chemical equilibrium of the reaction to the right.
Title: Re: Type of reaction unknown
Post by: Orcio_87 on April 21, 2021, 07:32:22 AM
@Skay Third reaction is nucleophilic substitution - with amine as nucleophile.

But I would not say that "HCl is side product". Product is clopidogrel hydrochloride, which can be deprotonated - by amine which is used in reaction or some other base - here it is K2CO3. Without K2CO3 reaction is still possible to do, but it will need more amine (compound 8 ) as source of base.
Title: Re: Type of reaction unknown
Post by: Meter on April 21, 2021, 08:02:50 AM
Why use HCl for Fischer esterification? Wouldn't the high water content of concentrated HCl give a low yield?
Title: Re: Type of reaction unknown
Post by: Orcio_87 on April 21, 2021, 08:17:08 AM
@Meter Dimethyl ether or methyl ether of 13 can be side-product if one will use conc. H2SO4 instead.
Title: Re: Type of reaction unknown
Post by: rolnor on April 21, 2021, 10:31:43 AM
Its anhydrous HCl, not HCl(aq)
Title: Re: Type of reaction unknown
Post by: Meter on April 21, 2021, 12:44:22 PM
Quote from: rolnor on April 21, 2021, 10:31:43 AM
Its anhydrous HCl, not HCl(aq)
Yes, but in the laboratory, how do you use anhydrous HCl? Isn't that a gas at STP?
Title: Re: Type of reaction unknown
Post by: rolnor on April 21, 2021, 03:26:47 PM
Yes, its a gas. You can make a solution in MeOH or EtOH by slowly mixing a little AcCl in the alcohol. Its a powerfull reaction, do it dropvise!
Title: Re: Type of reaction unknown
Post by: Meter on April 21, 2021, 03:27:47 PM
Quote from: rolnor on April 21, 2021, 03:26:47 PM
Yes, its a gas. You can make a solution in MeOH or EtOH by slowly mixing a little AcCl in the alcohol. Its a powerfull reaction, do it dropvise!
Thanks. Good to know.
Title: Re: Type of reaction unknown
Post by: Guitarmaniac86 on April 21, 2021, 03:39:11 PM
You can even get 4M HCl in anhydrous 1,4-dioxane too! Very useful reagent!