Chabrecek, P: Benzothiazole compounds. 26. synthesis of s-[1-acetyl-2-(2-oxobenzothiazol-3-yl)ethyl] 0,0(0,n,0,s)-dialkyl thio(dithio)phosphates and s-[1-acetyl-2-(2-thioxobenzothiazol-3-yl)ethyl] 0,0(0,s)-dialkyl thio(dithio)phosphat|es