Home >
Community >
How to synthesise 2-aminoethyl benzene
Upvote
32
Downvote
+ Synthesis
Posted by
Aarij Asher
How to synthesise 2-aminoethyl benzene
Several thoughts:
I can't see how you form toluene with a Grignard - it's certainly possible though
Radical chlorination of toluene with $\ce{Cl2}$ isn't the cleanest reaction.
To reduce the nitrile to the amine, you don't need to go through the amide.
Also, from ethylbenzene, it's very hard to introduce that amine group cleanly. You effectively just have a compound with C-H groups and you have to somehow introduce some kind of functional group into the non-benzylic position. Try to think backwards instead of forward!
The amine you want can be obtained by direct reduction of a nitrile either by simple $\ce{LiAlH4}$ reduction or hydrogenation:
That arrow essentially means "can be made from".
Of course, that's easy to make using a nucleophilic substitution reaction with $\ce{CN-}$ and benzyl chloride (for example):
To get from benzene to benzyl chloride, you could use a Blanc chloromethylation. So your forward synthesis would be:
and you might want to use catalytic $\ce{KI}$ in the nucleophilic substitution step. Of course, for such a simple compound, there are tons of ways to synthesise it. The amine could be made from reduction of an azide, or by a reductive amination, and so on. I strongly doubt my proposed route is the most efficient. Still, I think it should work.
Theoretically, you could use a Friedel-Crafts alkylation and a radical bromination to get to benzyl bromide instead:
I can't see how you form toluene with a Grignard - it's certainly possible though
Radical chlorination of toluene with $\ce{Cl2}$ isn't the cleanest reaction.
To reduce the nitrile to the amine, you don't need to go through the amide.
Also, from ethylbenzene, it's very hard to introduce that amine group cleanly. You effectively just have a compound with C-H groups and you have to somehow introduce some kind of functional group into the non-benzylic position. Try to think backwards instead of forward!
The amine you want can be obtained by direct reduction of a nitrile either by simple $\ce{LiAlH4}$ reduction or hydrogenation:
That arrow essentially means "can be made from".
Of course, that's easy to make using a nucleophilic substitution reaction with $\ce{CN-}$ and benzyl chloride (for example):
To get from benzene to benzyl chloride, you could use a Blanc chloromethylation. So your forward synthesis would be:
and you might want to use catalytic $\ce{KI}$ in the nucleophilic substitution step. Of course, for such a simple compound, there are tons of ways to synthesise it. The amine could be made from reduction of an azide, or by a reductive amination, and so on. I strongly doubt my proposed route is the most efficient. Still, I think it should work.
Theoretically, you could use a Friedel-Crafts alkylation and a radical bromination to get to benzyl bromide instead:
Several thoughts:
Also, from ethylbenzene, it's very hard to introduce that amine group cleanly. You effectively just have a compound with C-H groups and you have to somehow introduce some kind of functional group into the non-benzylic position. Try to think backwards instead of forward!
The amine you want can be obtained by direct reduction of a nitrile either by simple $\ce{LiAlH4}$ reduction or hydrogenation:
That arrow essentially means "can be made from".
Of course, that's easy to make using a nucleophilic substitution reaction with $\ce{CN-}$ and benzyl chloride (for example):
To get from benzene to benzyl chloride, you could use a Blanc chloromethylation. So your forward synthesis would be:
and you might want to use catalytic $\ce{KI}$ in the nucleophilic substitution step. Of course, for such a simple compound, there are tons of ways to synthesise it. The amine could be made from reduction of an azide, or by a reductive amination, and so on. I strongly doubt my proposed route is the most efficient. Still, I think it should work.
Theoretically, you could use a Friedel-Crafts alkylation and a radical bromination to get to benzyl bromide instead:
I don't like the alkylation step though.
Several thoughts:
Also, from ethylbenzene, it's very hard to introduce that amine group cleanly. You effectively just have a compound with C-H groups and you have to somehow introduce some kind of functional group into the non-benzylic position. Try to think backwards instead of forward!
The amine you want can be obtained by direct reduction of a nitrile either by simple $\ce{LiAlH4}$ reduction or hydrogenation:
That arrow essentially means "can be made from".
Of course, that's easy to make using a nucleophilic substitution reaction with $\ce{CN-}$ and benzyl chloride (for example):
To get from benzene to benzyl chloride, you could use a Blanc chloromethylation. So your forward synthesis would be:
and you might want to use catalytic $\ce{KI}$ in the nucleophilic substitution step. Of course, for such a simple compound, there are tons of ways to synthesise it. The amine could be made from reduction of an azide, or by a reductive amination, and so on. I strongly doubt my proposed route is the most efficient. Still, I think it should work.
Theoretically, you could use a Friedel-Crafts alkylation and a radical bromination to get to benzyl bromide instead:
I don't like the alkylation step though.
More
VOTE