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Tips for Building Structures for Substructure Searching

For a structure containing
ring systems, do you want to
block additional ring fusion?
(including spiro attachments
and bridging)
yes
Highlight one node in the ring.
QUERY DEF, RING ISOLATION.
Select "Isolated".
For a structure containing
atoms in a chain, do you
want to allow these atoms to
also be part of a ring?
yes
Highlight the atom(s).
QUERY DEF, NODE CHARACTERISTICS.
Select "Ring/Chain".
For a structure containing
chain bonds, do you want to
allow any of these bonds to
also be part of a ring?
yes
Highlight the bond(s).
QUERY DEF, BOND CHARACTERISTICS.
Select "Ring/Chain".
Do you want to allow bonds to
have any value?
yes
DRAW, BOND.
Select "Unspecified".
Do you want to allow bonds to
be either present or absent?
yes
Leave the bond out of the structure.
Add node characteristics of ring/chain.
Do you want to block substitution
at all positions in your structure?
yes
Run an EXACT or FAMILY structure
search.
Do you want to block substitution
at some positions in your structure?
yes
Add hydrogens at appropriate positions.
Do you want to force substitution
at a position in your structure?
yes
DRAW, VARIABLES.
  • A = anything but H
  • Q = anything but H or C
  • X = any halogen
  • M = any metal
  • CY= any ring
  • CB= any carbocycle
  • HY= any heterocycle
  • Ak= any carbon chain
Do you want to force substitution
at a position in your structure AND
define the substitution options?
yes
DRAW, G-GROUP.
Reproduced with the permission of CAS, a division of the American Chemical Society, from "Tips for Searching the CAplus & REGISTRY File." (CAS9613-0298)