4mmc freebase turns red with few acid

[Irving Langmuir]

What determines the color of 4MMC :

Yellowish - produced by ingestion of 4'-methyl-2-bromopropiophenone, making the product oily;
Yellow - Yellow-brown, brown - resins formed during overheating of the reaction mixture, iodine;
Greenish - obtained when 4'-methyl-2-bromopropiophenone gets into the final product;
Reddish, ginger, earthy colors- iodine / bromine contamination;
Blue, bluish - excess methylamine salts;
Black, dark brown pasty - n-methylpyrrolidone, DMSO, DMF.

 

[dodobird]

Most solvents used are real pain. Little research can avoid most issues.

 

[dodobird]

Ph at 7 before acidification is quite low, hbr and other side reactions. For clean salt crash ph before acid usually should be above 9 or 10. Did you do Na2Co3 wash. Would be better to add Na2Co3 before acid. Depends..ea try only 125 ml to begin with. Ma40 amination hindered plus don't use acetone. Basify after amination, add very little cold dw and add hcl37 drop wise by first placing solution in ice bath. After acid 1 hr.. add ice salt slurry if needed. Cheers