Substitution Reactions on Aromatic sp

Picryl halides react with 2-amino-4-methylthiazole. Again, the exocyclic nitrogen is the reactive center (288). and the product formed (128) is 

The amino group of 2-imino-3-phenyl-4-amino-5-carbethoxy-A4-thiazoline is very reactive and displaces the chlorine atom of various 2-chlorothiazoles (1577). 

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