Photolytic dehydrochlorination of N-chloro-N-alkyl amides: formation of N-(.alpha.-methoxyalkyl) amides

Abstract

The photoinduced dehydrochlorination, in methanol, of TV-chloro-N-alkyl amides with one substituent at the a position to nitrogen gave good yields of /V-(a-methoxyalkyl) amides and the parent amides as secondary products. JV-Chloro amides disubstituted at the a position gave mostly parent amides. In most cases no products resulting from 1,5 hydrogen transfer of amidyl radicals were observed. The quantum yields of decomposition of Nchloro-jV-methylpentanamide (la) were significantly greater than unity, indicative of a chain process for dehydrochlorination. The reaction was affected by the solvent, addition of base or radical inhibitors, concentration of TV-chloro amide, light intensity, and irradiation wavelength.

Heterocyclic compounds from Chrysanthemum coronarium L. and their inhibitory activity on hACAT-1, hACAT-2, and LDL-oxidation

“…and identified as methyl trans-ferulate (2, Allen, 1972), prunasin (3, Aritomi et al, 1985Cardona et al, 1992;Neilson et al, 2006), sambunigrin (4, Neilson et al, 2006), pterolactam (5, Nakano et al, 1972Iwasaki et al, 1979;Phan and Shannon, 1983), and adenosine (6, Grzelczak and Buchowicz, 1975;Cardin and Roy, 1985).…”

Dehydrogenation–halogenation of a 4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridin-4-one to provide a scaffold for acylpyridones

“…Our attention was therefore drawn to a report of the photolysis of N-chlorolactams to afford N-(α-methoxyalkyl)lactams. 19 After some experimentation, a solution of N-chloro compound 6…”

“…Other light sources were less efficient; for example, use of two home Solaria UV lamps gave 4 in just 40% (60% based on recovered 5). The mechanism for the dehydrochlorination of 5 is proposed to be via a radical chain process (Scheme 3): 19 homolysis of the N-Cl bond followed by H-atom abstraction from C-6 of 6, would leave a carbon radical at C-6 which, if it fragments to expel a chlorine atom, would generate an imine that could simply tautomerize to the stable acyl enamine form 4. The accompanying production of the N-H lactam 5 is proposed to arise from H-abstraction from the MeOH solvent; the HCl so-formed may also cause acid-promoted decomposition of 6 with generation of chlorine.…”

Progress in the Synthesis of N-Acyl-N,O-acetals

“…Phan and Shannon provided an original and efficient methodology to synthesize N-(-methoxyalkyl)amides 36 in methanol through photoinduced dehydrochlorination of N-chloro-N-alkylamides 35, which were monosubstituted at the -position to nitrogen (Scheme 17). 25 N-Chloro-Nalkylamides with two substituents in the -positions mainly produced parent amides under photolysis conditions. The reaction was affected by the concentration of amide 35, irradiation wavelength, and light intensity.…”