1- Alkyl-2-hydroxymethyl-5-nitro

Neben den bereits in Band VI genannten Beispielen konnen auch 1-Alkyl-5-nitro-imidazole in 2-Stellung hydroxymethyliert werden (1 -Alkyl-2-hydroxymethyl-5-nitro-imidazole). Diese Umsetzung wird normalerweise in Dimethylsulfoxid mit Paraformaldehyd bei 120-130" durchgefuhrt746- 748. 

For the reaction of fully saturated 1,3-dioxanes with electrophiles, an activation of the heterocycle by metalation either close to an appropriate functional group or by displacement of a functional group is necessary since deprotonation of unfunctionalized 1,3-dioxanes is not a common method. It was reported that 5-nitro-l,3-dioxanes were alkylated at C-5 using standard alkylation conditions (LDA, R-X) <2001TL105, 2006JOC2200> (Scheme 59) or by reaction with Michael acceptors <2002TL8351>. A 5-hydroxymethyl-5-nitro-l,3-dioxane was also amenable to alkylation after a photoinduced retro-aldol reaction had taken place in the presence of sodium methoxide. However, only 2-nitrobenzyl chloride was a suitable electrophile for an efficient alkylation <2004TL1737>. 

Hydroxymethyl-phenol reagiert mit Nitro-alkanen in einer Triethylamin/m-Xylol-Lo-sungzu 4-(2-Nitro-alkyl)-phenolen, 1,1 -Bis-[4-hydroxy-phenyl]-l -nitro-alkanen und in sehr geringen Ausbeuten zu 1-Nitro-l, 1,1 -tris-[4-hydroxy-phenyl]-me-than1 ... 

Formylation of amines and alcohols. Behai,8 discoverer of the reagent, found that it reacts unidirectionally with simple alcohols to produce alkyl formates free from acetates. Hurd et al. J found that acetic-formic anhydride (prepared from formic acid and ketene) reacts quantitatively with aniline to give formanilide. Another study10 established that acetic-formic anhydride mixes endothermally with 2-nitro-2-methyl-l-propanol, exothermally with 2-nitro-2-methyl-l,3-propanediol, and displays no appreciable temperature effect with either 2-nitro-l-butanol or tris-(hydroxymethyl)-nitromethane. Formic esters are favored by avoiding a high reaction temperature and by not using sulfuric acid as catalyst. The mixed anhydride has been used for the preparation of formyl fluoride.11... 

Attempts to brominate the free position 6 of compound 122 failed so also did the attempt to nitrate 121 or 122 because the nitro group entered the most accessible position of the phenyl ring to give either 6-(4-nitrophenyl)- (124), or 7-(4-nitrophenyl) derivative 125. Attempts to acylate, formylate, hydroxymethylate, chloromethylate of aminomethylate 6- or 7-substituted thiazolo[2,3-/]purinediones 121 and 122 also resulted in failure. The bromo group of 7-bromo derivative 123 did not react with either ammonia or amines (81KGS1267) (Scheme 34). The alkylation at N(3) with halogenoacetate is illustrated in Scheme 30. 

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