www.chemhome.net , a good website to look for chemical information, especially for those who do R&D or techical of chemistry.
this website listed many English websites , which can help us to find many useful information such as property of reagents, patents, many useful databases and so on!
I find that it is very useful so I share with others. If you want to use it , you can go to the home page of it ,then choose the English version.