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The reactivity of new formylating agents related to formamide has been investigated both experimentally and theoretically. The reaction in 1,2-dichloroethane between tris(diformylamino)methane (2) and several arenes, catalyzed by AlCl 3 or BCl 3 , was shown to proceed in good yields to afford the corresponding para-substituted aldehydes. The nature of the active electrophilic species was also investigated theoretically. Thus, the relative stability of the O-and N-protonated forms, as well as those of AlCl 3 adducts, of several formylat-

297Aromatische Aldehyde spielen in der chemischen und pharmazeutischen Industrie eine wichtige Rolle als Zwischenprodukte mit besonders hohem Wertschöpfungspotential.Die unter C,C-Knüpfung verlaufende Synthese der verwandten aromatischen Ketone ist bekanntlich sehr einfach durch die bereits 1877 entdeckte Friedel-Crafts-Reaktion möglich. Die aufbauende Synthese aromatischer Aldehyde ist wesentlich problematischer, weil nur wenige stabile Ameisensäurederivate bekannt sind, die eine mit Carbonsäurechloriden vergleichbare Reaktivität besitzen [2]. Im Jahr 1897 wurde von Gattermann und Koch die Formylierung von Alkylaromaten mit Hilfe des Systems CO/HCl, Cu(I)Cl/AlCl 3 beschrieben. Von Olah wurde ca. 60 Jahre später in dem System Formylfluorid/Bortrifluorid ein Formylierungsmittel gefunden, das dem Reagenztyp entspricht, der bei der klassischen Friedel-Crafts-Reaktion verwendet wird [3]. Bei anderen klassischen Formylierungsmethoden dienen -gegebenenfalls in situ erzeugte -Iminiumsalze als Formylierungsmittel. So können nach Gattermann Phenole, Phenolether, Alkylbenzole und kondensierte Aromaten mit dem System HCN/HCl/AlCl 3 formyliert werden. Die Methode wurde mehrfach verbessert und mo- Orthoamide. LIII [1]Abstract. Diformamide (1) reacts with activated aromatic compounds like toluene, anisole, m-xylene, 1,2-dimethoxybenzene in the presence of AlCl 3 to give N-(diarylmethyl)formamides 2a -d, the corresponding aromatic aldehydes 3 -6 are formed as by-products in low yields. From N,N-dimethylaniline and 1/AlCl 3 the triphenylmethane derivative 7 can be obtained. The reaction of anisole with N-methyl-diformamide (9) affords the formamide 10. The mixture of formamide, P 4 O 10 and AlCl 3 reveals to be a reagent which is capable to formylate toluene and anisole, resp. Triformamide (14)/AlCl 3 is an effective formylating system which allows the preparation of aromatic aldehydes (e.g. 3,4,17 -32) from the corresponding aromatic hydrocarbons. Aluminiumchloride can be replaced by borontrichloride. The yields of the formylation reactions depend strongly from the reaction conditions (molar ratio: aromatic hydrocarbon/ AlCl 3 /14; solvent, reaction temperature). The scope of the reaction covers nearly complete those of the Gattermann-Koch-, Gattermann-and Vilsmeier-Haack-reaction.

N, N, N´, N´-Tetraalkyl-chloroformamidinium chlorides 6 are prepared from N, N, N´, N´-tetraalkylureas 5 and phosgene in acetonitrile. The iminium salts 6 react with primary and secondary amines in the presence of triethylamine to give N, N, N´, N´, N´´-pentasubstituted and N, N, N´, N´, N´´, N´´- hexasubstituted guanidinium salts 7 and 8, respectively, Treatment of the guanidinium salts 7 with sodium hydroxide in excess affords the N, N, N´N´, N´´-pentasubstituted guanidines 9a - 9aa. Additionally, the N, N, N´, N´, N´´-pentasubstituted and N, N, N´, N´, N´´, N´´-hexasubstituted guanidinium salts 7l´, 7p´ and 8a - c can be obtained from the reaction mixtures by addition of stoichiometric amounts of sodium hydroxide. A modified method is described for the preparation of guanidinium salts possessing dialkylamino substituents consisting of two long-chain alkyl groups (>C14). Some guanidines 9 were alkylated with allyl chloride and bromide, ethyl bromide, butyl bromide, benzyl bromide and chloride, dimethyl sulfate, diethyl sulfate, and methyl methansulfonate to give the corresponding guanidinium salts 11 - 15. By alkylation of the N, N, N´, N´, N´´-pentasubstituted guanidine 9v with triethyloxonium tetrafluoroborate the guandinium tetrafluoroborate 16a is accessible. N-Functionalized guanidinium salts 17 - 18a - c result from the reaction of N, N, N´, N´, N´´-pentasubstituted guanidines with ethyl bromoacetate and bromoacetonitrile, respectively, and subsequent anion exchange with sodium tetraphenylborate. N, N, N´, N´-Tetramethylguanidine (21) adds to ethyl acrylate to give the labile guanidine 22, which forms the guanidinium salt 23a on treatment with methyl iodide. Zwitterionic guanidinium salts 25 result, when N, N, N´, N´, N´´-pentasubstituted guanidines are treated with sultones 24.

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A Formylation Agent for Aromatic Compounds of Wide Scope. -A reagent system from title compound (II) and AlCl3 allows for efficient formylation of aromatic compounds. The scope of this system is comparable with the Olah formylation and the Gross-Rieche procedure. -(KANTLEHNER, W.; HAUG, E.; SCHERR, O.; STOYANOV, E. V.; MEZGER, J.; ZIEGLER, G.

The preparation of sodium diformamide (7) from formamide and sodium methanolate under azeotropic removal of methanol with cyclohexane, or from formamide and sodium ethanolate in ethanol, is described. Diformamide (8) can be prepared by treatment of sodium diformamide (7) with formic acid. Triformamide (triformylamine) (1) is formed in the reaction of sodium diformamide with inorganic acid halides such as SOCl2, SO2Cl2 or PCl3 in acetonitrile at low temperatures. Triformamide (1) can be prepared on a large scale by the action of methanesulfonyl chloride on finely powdered sodium diformamide (7) in acetonitrile. Tris(diformylamino)methane (4) can be formed as a side product. A procedure was developed for the large-scale preparation of N;N-diformylacetamide (6) from sodium diformamide and acetyl chloride. Triformamide (1) can be prepared from N;Ndiformylacetamide (6) and diformamide with good yields