Nitro acetalation

It was mentioned above that acetalic nitroxyl radicals produced by addition of a-alkoxyalkyl radicals to tetranitromethane (TNM) undergo a spontaneous heterolysis with the carbon center being oxidized and TNM reduced (to nitro-form anion (NF ) and NOj). In order to see the addition-elimination sequence with acyclic a-alkoxyalkyl radicals there have to be two (electron-withdrawing relative to methyl) hydrogens at Q. Even one alkyl group at Q is sufficient to make khs > 10 s and therefore too fast to measure. If, however, an alkyl group which is inductively deactivated is introduced at Q, the k values fall in the... 

Dipyrrolidino- bzw. 7,7-Dipiperidino-bicyclo[4.1.0]heptan setzen sich als N,N-Acetale bei 25° unter Stickstoffatmosphare mit Nitro-alkanen in Gegenwart von Jodmethan untcr C-Alkylierung um z.B.11 ... 

Primate Nitro-aliphaten lassen sich mit Natriummethanolat unter Saure-Katalyse (Schwe-felsaure) in Methanol bei — 35° in guten Ausbeuten unter Substitution der Nitro-Gruppe in O.O-Acetale fiberfuhren5 ... 

One method of synthesizing the aspirin substitute, acetaminophen, involves a three-step procedure as outlined in Fig. PI. 113. First, p-nitrophenol is catalytically hydrogenated in the presence of aqueous hydrochloric acid to the acid chloride salt of p-aminophenol with a 86.9% degree of completion. Next the salt is neutralized to obtain p-aminophenol with a 0.95 fractional conversion. Finally, the p-aminophe-nol is acetalated by reacting with acetic anhydryde, resulting in a yield of 3 kg mol of acetaminophen per 4 kg mol. What is the overall conversion fraction of p-nitro-phenol to acetaminophen ... 

Die bei der Reaktion primar entstehenden Acetale lassen sich bei aciden Methylen-Ver-bindungen nur in Ausnahmefallen erhalten. So ergibt N itroessigsaure-methylester mit Or-thoameisensaure-trimethylester den 3,3-Dimethoxy-2-nitro-propansdure-methylester zu... 

Durch die Einwirkung von Licht lassen sieli 2-Nitro-benzaldehyd-acetale in 2-Nitroso-bmzoesiiureeder umwandeln1-3 z. B. ... 

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