https://patents.google.com/patent/US4196286A/en
US4196286A - Process for the manufacture of basic oxazine dyestuffs - Google Patents
Process for the manufacture of a basic oxazine dyestuff of the formula (1) ##STR1## in which R, R 2 and R 3 denote alkyl with 1 to 4 carbon atoms and R 1...
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