Sladowska H, Bartoszko-Malik A, Zawisza T
Farmaco Sci. 1985 Jan;40(1):58-64. doi: 10.1002/chin.198523233.
It was stated that esters of 3H-2-imino-7-methyl-4-oxopyrido [3,2-e]-1,3-thiazine-5- and -6-carboxylic acids (I, II) undergo the Mannich reaction giving the corresponding 3-aminomethyl derivatives (III-XIV). Derivatives of ester II [(XII) and (XIV)] showed distinct analgesic and antiserotonic activities.