NCI Platted has a repository of compounds that are available at no cost to further NIH funded "Cancer Research".
Here is a description of the process received (July 2014):
There is no charge for the compounds from our repository. However, investigators are responsible for all shipping costs.
To request compounds from our Open Chemicals Repository, please visit: http://dtp.cancer.gov/RequestCompounds/
It is important to note that each request for materials is unique. The Simple Letter of Agreement (SLA) does not serve as a blanket agreement for all compound requests.
The maximum number of vialed compounds that can be requested is 40 compounds in one request. This does not apply to the plated sets as there are more than 40 compounds on the plates. Investigators are required to wait an additional 30 days from the time the first 40 compound request is placed to request additional material. Our plated sets are already established. More specifically, we will be unable to provide customized plated sets.
Investigators are encouraged to request enough material to conduct their own independent assessments of the quality/purity/veracity of structure for each compound as the vast majority of agents in our repository have been donated from various sources. And, due to confidentiality we are unable to disclose the identities of the originators of the substances.
In general, the typical amount requested for in vitro research is up to 10 mg (this does not apply to the plated sets as they are already set with a known concentration). You will have an idea as to whether the amount you are seeking is likely to be fulfilled during this process.
A few links you may find helpful: http://www.dtp.nci.nih.gov/dtpstandard/dwindex/index.jsp and http://www.dtp.nci.nih.gov/branches/dscb/Cmpd_Ordering_Flowsheeet.pdf and http://www.dtp.nci.nih.gov/dtpstandard/ChemData/index.jsp Instructions for structure searches can be found at our website, http://dtp.cancer.gov/docs/dtp_pubchem_search.html
Our system does not recognize ZINC codes. You will need an NSC number.
We do not have a similarity search on the DTP web site at the moment. All our open compounds are in PubChem and you can search that database by similarity. See http://pubchem.ncbi.nlm.nih.gov/search/search.cgi. You can also go to http://www.ncbi.nlm.nih.gov/pcsubstance and search for NSCNNNN where NNNN is the NSC number you are seeking. That will lead you to a result page that has menu picks for related structures.
The status of your compound request can be monitored via the following link: http://dtp.cancer.gov/OrderAuth/
Our process is such that each submission for material from the NCI/DTP repository is regarded as a request. There are no assurances that the requested amount(s) will be supplied, but we do our best to accommodate the requested amounts based on various factors; amongst those considerations are availability of material and the information provided by investigators in the "assay description" field justifying the quantities being sought. In instances where our system indicates that a particular agent is not available, it is unlikely that the agent will be replenished and a commercial source may need to be pursued.