Structure and molecular interactions of anti-thyroid drugs. Part 1. Dipole moments of carbimazole and methimazole, and conformation of carbimazole

A new and efficient approach to the synthesis of 6-amidino-2-oxopurines

“…This duplication of bands may indicate the co-existence of conformers E and Z (19E and 19Z) in the solid state. A similar situation was previously reported for carbimazole, 10 where two carbonyl groups are present in a comparable relative position. In this case, the two sets of bands registered in the IR spectrum of this compound were equally assigned to the Z and E conformers.…”

“…The signals at δ 155.8 and 126.2 ppm showed three-bond interactions with C(8)H and were assigned respectively to C(4) and C(5). All the carbon atoms of the tosyl and aryl groups were clearly identified with this technique, and the remaining carbon atoms could be assigned with certainty to C(2), C(6) and C (10).…”

Structure and molecular interactions of anti-thyroid drugs. Part 2. Electron donor properties of carbimazole 1

“…The classical method, 24 which follows the IR absorbance decrease of the 3614 cm Ϫ1 O᎐H band of FP on the addition of increasing quantities of CBZ, is only able to give the total concentration of hydrogen-bonded complexes [1]…”

Reaction of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine

“…1 These compounds are used for the treatment of hyperthyreosis (imidazole and pyrim idine derivatives), 2 leukemia (purine derivatives), 3 and cerebrovascular diseases. 4 The thioamide group, which is present in imidazole , oxazole , thiazole , hydantoin , thiadiazole , and barbiturate and uracil based com pounds, is believed to be a pharmacophore responsible for the antithyroid activity, 5, 6 with the result that these com pounds exhibit antithyroid and goitrogenic properties.…”