2- piperidine hydrobromide, preparation

To a solution of 28 g (0.1 mol) 2-carbethoxymethylene-3-methyl-5-bromo-4-thiazolidinone prepared as described In 200 ml benzene Is added (0.2 mol) piperidine and the mixture is allowed to stand for 3 hours at 25°C. The resulting suspension is filtered to remove the precipitated piperidine hydrobromide and the filtrate is evaporated to dryness. The residue is taken up in ether, filtered and the filtrate saturated with dry hydrogen chloride to yield the hydrochloride salt of 2-carbethoxymethylene-3-methyl-5-piperidino-4-thiazolidinone, MP 158°C to 159°C. 

The A-substituted >-(bromoalkyl)cyanamide may be isolated by vacuum-distillation, or the crude product may be used for further reactions for instance, the Br may be replaced by N(Alkyl)2,1153 or the CN may be split off by boiling 48% HBr. An example of the last-mentioned reaction is the preparation of 7V-(5-bromopentyl)aniline hydrobromide by boiling for 48 h a mixture of 48 % HBr and the Br(CH2)4CH2-N(C6H5)-CN obtained from 1-phenyl-piperidine and BrCN.1158... 

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