Appreciated your explanation, so glad you sharing knowledge with me. And you are right, the 1st vendor sent me precursor claim is 5fadb pair bromobutane, i can make solid form very easy, I believed what I make is adb not 5fadb. Ps: 2nd order this vendor take money and disappear!
Now 2nd vendor I try use pair with bromobutane fail, then pair 5bromo1pentene also fail. So the vendor ask me try the other precursor and test it again. Lol headache!