6273-17-2Relevant academic research and scientific papers
S-DERIVATIVES OF THIOUREA. XX. REACTION OF THIOUREA WITH TERMINAL DIBROMOALKANES
Tkachenko, S. E.,Sal'nikov, D. I.,Lys, Ya. I.,Fedoseev, V. M.,Zhurilin, V. S.
, p. 878 - 884 (2007/10/02)
The kinetics of the reaction of thiourea with terminal dibromoalkanes Br(CH2)nBr, where n= 1-5, were investigated by radiochromatography.It was established that the reaction of thiourea with 1,4-dibromobutane and 1,5-dibromopentane leads to the formation of only products from substitution of one or two bromine atoms by thiourea.In the case of 1,2-dibromoethane and 1,3-dibromopropane 2-amino-2-thiazoline and 2-amino-5,6-dihydro-4H-1,3-thiazine were found in addition to the analogous substitution products.The rate constants of the individual stages of the processes were determined.A series of S-bromoalkylisothioureas Br(CH2)nSC+.(NH2)2Br-, where n= 2-5, were synthesized.It was shown that the rate of their reaction with thiourea is higher than for terminal dibromoalkanes and (for n= 3-5) alkyl halides Br(CH2)nH.It was found that the reactivity varies irregularly with increases in the length of the polymethylene chain for bromoalkylisothioureas, and this evidently results from the superimposition of several effects from the substituent.
