The utilization of nicotinamide derivatives and related compounds by mammals, insects and bacteria

No appreciable reaction took place when NaF, in place of KF, was heated with 1:2:4-chlorodinitrobenzene employing the conditions given above. Physiological examination(1) A batch of 23 rabbits, rats, guinea-pigs and mice were exposed to a Ct* of 5000 mg.min./m.3 in a 1-87m.3static chamber.The material was sprayed in ether (25 ml.).During exposure the animals suffered from irritant action, but recovered after being removed from the chamber.At the end of a week there were no deaths.The batch was then re-exposed to the same Ct.The irritation seemed more intense and all four guinea-pigs died in 48 hr.The post- mortem examination showed changes typical of those caused by a lung irritant.(2) Subcutaneous injection into mice, using propylene glycol as solvent: 100 mg./kg.killed 1/6.(3) Vesicancy on human skin.Benzene solutions of 1:2:4-fluorodinitrobenzene (F) were dropped on to the right arms of two subjects, and similar solutions of 1:2:4-chloro- dinitrobenzene (Cl) were dropped on to the left arm.There was free evaporation.5 mg.drops of 1% solution (i.e. 50,tg.)had no effect within 4 days.5 mg.drops of 10% solutions (i.e.500 pg.) produced considerable irritation as follows: Subject 1. F patch.Smarting and swelling in 7 hr., blister without surrounding erythema in 36 hr.No change when blister was pricked on 3rd day.Scar almost healed by 9th day.' Cl patch.During the first 9 days there was no more than a red weal.By the 12th day there was irritation and swelling which subsided on the 15th day.Subject 2. F patch.Immediate smarting and swelling which persisted for 1 day, and subsided the next day without a blister.After 3 days the skin broke down with formation of pus and scabs.After 8 days only a scar remained.CI patch.Slight redness during first 8 days.Swelling on 9th day and weal rash of vesicles op 10th day.The spots oozed freely on the 14th day.Recovery on 20th day.SUMMARY 1.A convenient method of preparing 1:2:4- fluorodinitrobenzene is described.2. The compound is relatively non-toxic in comparison with the highly toxic fluoroacetates.It produces, however, a slight vesication on human skin.Our thanks are due to the Director General of