selectivity rule for amines

Hi,

I'm using "react -l -r" to cap amines with an acetyl but I only want one amine to react as defined by a "selectivity" rule.

e.g. primary > secondary > aromatic amine 

How do I write multiple selectivity rules based on smarts?

'[NX3v3;!$(N[C,S]=[O,S]);!$(NN):1]([H:2])>>[N:1]C(=O)C..s:match(ratom(1),"[NH2;$(NC)]")'

works for the primary over all others but when I add a second rule that doesn't seem to be applied.

i.e. ..s:match(ratom(1),"[NH2;$(NC)]")..s:match(ratom(1),"[NH;$(NC)]")

Of course this gets more complicated, if there are two primary amines then I may want the least hindered to react.

Is there some way to use a sequence of reactions getting less specific each time?

Thanks

Stephen

Hi Stephen,

Separate the selectivity rules with semicolons, and it will work.

Examples:

$ react -r '[NX3v3;!$(N[C,S]=[O,S]);!$(NN):1]([H:2])>>[N:1]C(=O)C..s:match(ratom(1),primary_amine);match(ratom(1),secondary_amine)' "NCCNC"
CNCCNC(C)=O

$ react -r '[NX3v3;!$(N[C,S]=[O,S]);!$(NN):1]([H:2])>>[N:1]C(=O)C..s:match(ratom(1),secondary_amine);match(ratom(1),primary_amine)' "NCCNC"
CN(CCN)C(C)=O

In the first example the primary amine will react, in the second example the secondary amine. The only difference between two examples is the order of the selectivity rules. It is possible to use more than two selectivity rules.

Zsolt