Salute sir William! I carried out the synthesis of 3cmc from 2Br-3Clpropiophenon CAS 34911-51-8 in strict accordance with this manual with the only difference that I used DMSO instead of NMP, but the result is still not satisfactory. A glass with a mixture of all the components specified in the manual, after acidification to pH=6, has been in the freezer for several hours at a temperature of -20⁰C, and no signs of crystallization are even observed. Only at the bottom of the glass does a radical black substance slowly collect, the consistency of which is very similar to used car oil. I have a question for all the experienced users of this Internet resource and in particular for the experts: what could be the reason for my failure, if the synthesis of 4MMC from BK-4 in simple DCM was successful and the yield was about 50%? I would be grateful for any rational and constructive explanation.