http://pmgb.wordpress.com/2008/03/23/n-alkylation-of-primary-amines-to-secondary-amines/ chemical reaction procedures Tue, 10 Nov 2009 16:18:40 +0000 http://wordpress.com/ hourly 1 http://pmgb.wordpress.com/2008/03/23/n-alkylation-of-primary-amines-to-secondary-amines/#comment-132 ian Wed, 21 Jan 2009 03:02:56 +0000 http://pmgb.wordpress.com/?p=7#comment-132 iodo is better leaving group the rxn could just be run longer in the case of hindered bromides. the reason yeilds are low is water in inhibiting the sn2 reaction. also noted the higher dielectric constant aprotic solvents give better yeilds and selectivity condidered dimethyl sulfone? iodo is better leaving group the rxn could just be run longer in the case of hindered bromides.
the reason yeilds are low is water in inhibiting the sn2 reaction.
also noted the higher dielectric constant aprotic solvents give better yeilds and selectivity
condidered dimethyl sulfone?

]]> http://pmgb.wordpress.com/2008/03/23/n-alkylation-of-primary-amines-to-secondary-amines/#comment-19 pmgb Tue, 01 Apr 2008 19:58:44 +0000 http://pmgb.wordpress.com/?p=7#comment-19 There is a typo - we took one eq. of bromide. The yield is variable with our substrates. Sometimes we improved the yields to 40-50% by adding 1 eq. sodium iodide or tetrabutylammionium iodide (TBAI) to the reaction mixture. With activated halides (benzylic chlorides/sodium iodide system) we obtained the products of mono N-alkylation in excellent yields. There is a typo – we took one eq. of bromide. The yield is variable with our substrates. Sometimes we improved the yields to 40-50% by adding 1 eq. sodium iodide or tetrabutylammionium iodide (TBAI) to the reaction mixture. With activated halides (benzylic chlorides/sodium iodide system) we obtained the products of mono N-alkylation in excellent yields.

]]> http://pmgb.wordpress.com/2008/03/23/n-alkylation-of-primary-amines-to-secondary-amines/#comment-14 gilgerto Tue, 01 Apr 2008 19:03:35 +0000 http://pmgb.wordpress.com/?p=7#comment-14 First why using only around 0.5 Eq of the bromide abd the get a very bad 15% yield? The origiginal paper in JOC (67, 674) states over 1 Eq of the bromide. Cesium effect for mono alkylation of primary amines is a great concept on paper but did'nt work well in my hands, but I know poeple who used this methodology with succes. First why using only around 0.5 Eq of the bromide abd the get a very bad 15% yield? The origiginal paper in JOC (67, 674) states over 1 Eq of the bromide. Cesium effect for mono alkylation of primary amines is a great concept on paper but did’nt work well in my hands, but I know poeple who used this methodology with succes.

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