Abstract
1) It has been found that 1-(2-dimethylaminoacyl)-3-(4-antipyrinyl) urea derivatives, whose syntheses were described earlier, unexpectedly had low toxicity and a high safety margin. This is rather interesting considering that 4-antipyrinylurea is the final metabolite of aminopyrine. Therefore, compounds of this series, 4-antipyrinyl-thiourea derivatives (XIII to XXIX, XXXVIII, XXXIX) and 1-(4-antipyrinyl)-1-methylurea derivatives (XXXIII to XXXVII), were prepared.
2) Reaction of 4-aminoantipyrine (I) and CSCl2 affords 4-antipyrinyl isothiocyanate (II) while the reaction of (I) and COCl2 gives 1, 3-diantipyrinylurea (XXXI). Reaction of 4-methylaminoantipyrine (I′) and COCl2 affords N-4-antipyrinyl-N-methylcarbamoyl chloride (XXXII). Condensation of (II) and (XXXII) with various amines afforded the above-mentioned urea derivatives.
