Some Pharmacological Reactions of Benzothiazole.

Abstract

Benzothiazole was prepared according to the method of Bogert and Stull, 1 by condensing o-amino thiophenol hydrochloride with formaldehyde. The constant boiling point of 231° C. corresponded with that given in the literature.

Owing to the fact that many compounds containing reduced or divalent sulfur are physiologically active, it seemed worth while to test the pharmacological action of this base. Accordingly, experiments of 2 types were performed; namely, cutaneous and intravenous tests.

In the cutaneous tests, a minute droplet of the oil was placed on the unbroken skin of the forearms of women and of men. Forty per cent of the number tested (43) developed a local dermatitis: the redness, swelling, and violent itching involving an area of at least 2 sq. cm. In the attempt to correlate these positive findings with various factors, it was observed that blondes seemed to be more susceptible than brunettes, but that sex apparently played no part. Two remarkable phenomena were noted; namely, delayed reactions, and increased hypersensitivity with repeated application. In most of the cases, the reaction appeared in from 2 to 18 days after the oil had been applied (average 91/2 days), and in many it reappeared after having subsided for a few days. In one case, the application of the drug to the right wrist after the reaction on the left wrist had partly subsided caused, in addition to a direct reaction, a highly intensified recurrence of the original reaction of the left wrist.

For the intravenous administration, the benzothiazole was emulsified in saline or in an autogenous serum. Injection into cats caused a marked fall in blood pressure, with an increase in the pulse rate. The effect on the respiration varied, depending on the dosage. A small dose sometimes caused an increase in both the rate and the amplitude, while larger doses usually had the opposite effect.