You might be better off checking out the spice isle at your local grocery stores. You've got lots of precursors for phenethylamines if you have the stuff to work it up. If you can fractionally distill cinnamon, nutmeg, vanilla etc. Lots of natural essential oils can be used as precursors. Check Strikes and Festers books for specifics. I don't think birch oil has any clandestine use., but look into other local plants in your area. I've got lots of sassafras around me for MD compounds for example. Some people probably have khat or other things growing wild they can use and don't know about.