Farina Brackmann, D. S. Yufit, J. Howard
Feb 1, 2005
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0
Influential Citations
10
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Journal
European Journal of Organic Chemistry
Abstract
tert-Butyl N-[1-(hydroxymethyl)cyclopropyl]carbamate (8) was converted into spirocyclopropanated analogues 14-CP and 14-CT of the insecticide Thiacloprid (2) in six simple steps with overall yields of 24 % each, along with their regioisomers 13-CP and 13-CT in overall yields of 17 and 15 %, respectively. The spirocyclopropanated analogues 27-CP and 27-CT of the insecticide Imidacloprid (1) were prepared from 8 in five steps in an overall yield of 10 % each, along with their regioisomers 20-CP and 20-CT in an overall yield of 8 and 7 %, respectively. The key step in all preparations was a cocyclization of an appropiately protected (1-aminocyclopropyl)methyl derivative with S,S-dimethyl cyanodithioiminocarbonate (11) or nitroguanidine (22). The structures of several final products and by-products were verified by X-ray crystal structure analyses.