Synthesis of Symmetrically and Unsymmetrically Substituted .alpha.-Diones from Organometallic Reagents and 1,4-Dialkylpiperazine-2,3-diones

Structurally Characterized Hetero‐Oligopolyphenylenes: Synthetic Advances Toward Next‐Generation Heterosuperbenzenes

“…Each retains the same arrangement of four peripheral functional groups and four ortho-imine nitrogen atoms, characteristic of the known nitrogen-heterosuperbenzenes (Scheme 2). Alkyl, ethynyl and bromo-substituted tetraphenylcyclopentadienones of the type required were accessed by a two-fold Knoevenagel condensation [14] of the appropriate 1,2-diketone (from the synthesis by Mueller-Westerhoff) [15] and the 1,3-diarylacetone (from the modified synthesis of des Abbayes). [16] In this manner the functionality achieved can be uniform throughout; or can consist of two pairs of substituents depending on whether they are of diketone or propanone origin.…”

“…These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. Single-crystal analyses were made with a Bruker SMART APEX CCD area detector by using graphite monochromized Mo Ka (l = 0.71073 ) radiation at 153(2) K (8,15,16) and 298(2) K (10,11,12). The data reduction was performed by using SAINT.…”

Novel Perylene Chromophores Obtained by a Facile Oxidative Cyclodehydrogenation Route

“…Afterwards, 12 was converted into the desired compound 13 by a carbonylation reaction with iron pentacarbonyl under phase-transfer conditions following the reports of Otsuji [22] and Thilmont (yield: 67 %). [23] The synthesis of the alkyl-substituted diketone 17 was accomplished by using a procedure of Mueller-Westerhoff, [24] which includes lithiation of 4-bromododecylbenzene (16) with sec-butyllithium in tetrahydrofuran and subsequent treatment with 1,4-dimethylpiperazine-2,3-dione (yield of 17: 50 %). The aforementioned 4-bromododecylbenzene (16) was readily available by Friedel ± Crafts acylation of bromobenzene (14) with lauroyl chloride (yield: 53 %) followed by a Wolff ± Kishner reduction of the resulting ketone 15 (yield: 76 %).…”

Synthesis of 2‐(Arylamino)‐2‐(arylimino)acetamides

“…Symmetrical structures are very common and include, for example, oxalyl chloride, [1,2] dialkyl oxalates, [3] 1,4-dimethylpiperazine-2,3-dione, [4] N,NЈ-dimethoxy-N,NЈ-dimethylethanediamide, [5] oxaldiimidoyl dichlorides A, [6] dialkyl oxaldiimidoates, [7] oxaldiamidines B [8] or dithiooxalates C. [9] Unsymmetrical derivatives are more rare and include ethyl 2-chloro-2-oxoacetate [10] and related derivatives, such as ethyl 2-(N-imidazolyl)-2-oxoacetate [10] and 2-ethoxy-N-methoxy-N-methyl-2-oxoethaneamide. [10] In addition, unsymmetrical imidoyl derivatives have been reported which include 2-(arylimino)-2-chloroacetates D, [11] 2-chloro-2-hydrazonoacetates [12] and 2-alkoxy-2-iminoacetates E. [13] The synthesis of two examples of ethyl 2-(arylamino)-2,2-dichloroacetates, which can be regarded as hydrochlorides of D, was reported as early as in 1877 and a few synthetic applications have been also described.…”