The effect of copper salts on the thermal decomposition of benzoyl peroxide in benzene

Sandmeyer reactions. Part 4.1 An investigation into the cyclisation modes of Pschorr phenanthrene synthesis

“…The major methyl fluorophenanthrene-10-carboxylate, 14a [identified as reported in Results (v)], eluted after 10.8 min, and the minor, 13a, after 13.0 min. The mass spectra of the two isomers were essentially identical: m/z 254 (100%, M ϩ ), 223 (85), 195 (68), 194 (35), 175 (12), 169 (7) and 168 (7). When allowance is made for the mass of F, the fragmentation pattern is essentially the same as that observed for the unsubstituted ester 21.…”

“…The prevailing condition of excess Cu 2ϩ would ensure the oxidation of the spiro-cyclohexadienyl radicals 15 to 16, which would be followed by rearrangement of the carbocation to give the same products as Ar 2(6) -6 cyclisation (Scheme 3). [35][36][37] In an endeavour to detect whether the cyclising radical 8c might be capable of Ar 1 -5 cyclisation, we treated methyl (E)-3-(2-iodophenyl)-2-(phenyl)propenoate 20b with tributyltin hydride in benzene solution at reflux, initiating the reaction with azoisobutyronitrile. Under these essentially reductive conditions, it was hoped that any of the spiro-cyclohexadienyl radical 15c might either be reduced or dimerised.…”

“…54 The following reaction sequence is typical. (16), 214 (18), 194 (19), 183 (35), 123 (100), 119 (60), 95 (35)…”

“…HCl, 1 : 2) [Found: M ϩ (amine), 271.1012. C 16 H 14 FNO 2 requires 271.1009]; m/z 271 (45%, M ϩ ), 240 (90), 238 (25), 222 (20), 212 (100), 211 (80), 183 (30), 165 (15), 117 (15) and 90 (15); ν max (Nujol)/cm Ϫ1 3000 and 2500 (NH Cl requires 303.0320); m/z 305 (1.5%, M ϩ ), 303 (5%, M ϩ ), 286 (5), 274 (2), 258 (20), 242 (17), 240 (10), 230 (23), 213 (11), 199 (7), 195 (8), 176 (35), 165 (40) 35 ClNO 4 requires 317.0455); m/z 319 (0.3%, M ϩ ), 317 (1.0%, M ϩ ), 290 (0.5), 288 (2), 286 (2), 274 (5), 272 (15), 260 (8), 258 (25), 232 (5), 230 (15), 176 (28), 165 (25), 141 (33) 35 ClNO 2 requires 287.0713]; m/z 289 (15%, M ϩ ), 287 (45%, M ϩ ), 258 (30), 256 (100), 230 (25), 229 (30), 228 (80), 227 (65), 193 (50), 165 (40) and 117 (18); ν max (Nujol)/cm Ϫ1 2900 and 2600 (NH (15), 208 (10), 196 (32), 176 (20), 152 (16), 119 (68) Methyl phenanthrene-9-carboxylate, 21. Methyl (E)-3-(2diazoniophenyl)-2-phenylpropenoate (50 mg) was dissolved in 50 cm 3 of an aqueous solution of Cu(NO 3 ) 2 (0.1 mol dm Ϫ3 ).…”

Nitrous Oxide as a Radical Scavenger

“…7,8 There is no doubt that the radical species, such as benzoyloxyl, phenyl, and phenylcyclohexadienyl radicals, are involved in the decomposition. 7,8 It has been also reported that photochemical decomposition of benzoyl peroxide (10 -3 M) in Freon 113 produced 8% of benzene and 7% of phenyl benzoate in the absence of cyclohexane and 35% of benzene in the presence of cyclohexane (0.06 M). 9 It has also been shown that phenyl and benzoyloxyl radicals are involved in the mechanism of formation of products in the photochemical reaction of benzoyl peroxide.…”