1: With methanol; sodium hydroxide; water T=1 - 40°C; 2.5 h; 2: With hydrogenchloride; water

1: 3,4-dihydro-2H-1,4-benzothiazin-3(4H)-one With sodium hydride in N,N-dimethyl-formamide T=0 - 40°C; 0.5 h; 2: bromoacetic acid methyl ester in N,N-dimethyl-formamide T=1 - 40°C; 2.5 h;