Acylation of fluorine-containing spiro[cyclopropane-1-pyrazolines] and dehydrohalogenation of the resulting adducts |
| |
Authors: | E V Guseva Yu V Tomilov |
| |
Institution: | (1) N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation |
| |
Abstract: | Acylation of 6-(1-fluorovinyl)-6-methyl- and 6-(2,2,3,3-tetrafluorocyclobutyl)-4,5-diazaspiro2.4]hept-4-enes with acetyl chloride proceeds as electrophilic addition to the N(5) atom and is accompanied by opening of the cyclopropane ring to give 1-acetyl-3-(2-chloroethyl)-5-(1-fluorovinyl)-5-methyl- and 1-acetyl-3-(2-chloroethyl)-5-(2,2,3,3-tetrafluorocyclobutyl)-4,5-dihydropyrazoles, respectively. Under the same conditions, acylation of 6-(2,3,3-trifluorocyclobut-1-enyl)-4,5-diazaspiro2.4]hept-4-ene is not regioselective. The (2-chloroethyl) pyrazolines obtained undergo dehydrochlorination into vinylpyrazolines in the presence of an excess of MeONa in MeOH. The reaction of 4-acetyl-6-(2,3,3-trifluorocyclobut-1-enyl)-4,5-diazaspiro2.4]hept-5-ene with MeONa results in selective replacement of the F atom at the double bond by a methoxy group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 419–422, February, 2005. |
| |
Keywords: | fluorine-containing spiro[cyclopropane-1-pyrazolines] acylation acetyl chloride cyclopropane ring opening dehydrochlorination NMR spectra |
本文献已被 SpringerLink 等数据库收录! |
|