Optically active bithienyls. VIII. Synthesis of 3,3′,6,6′-tetramethyldiphenic acid was written by Gronowitz, Salo;Hansen, Gunnar. And the article was included in Arkiv foer Kemi in 1967.Formula: C10H9NO2 The following contents are mentioned in the article:
cf. CA 62: 11757d. The title compound (I) was prepared for comparison of its racemization rate with that of its bithienyl analog (II) (G. and Beselin, CA 59: 15241g). The procedure for condensation of 2,5-Me2C6H3NH2 with CCl3CHO.H2O and NH2OH.HCl (Baker, et al., CA 46: 10176h) was modified and yielded 78% 2,5-Me2C6H3NHCOCH:NOH (III), m. 153-6°. III cyclized with 86% H2SO4 yielded 76% 4,7-dimethylisatin decomposing at 270° which on oxidation with alk. H2O2 yielded 68% 3,6-dimethylanthranilic acid (IV), m. 119-20°. The diazonium salt of IV (Atkinson and Lawler: Organic Syntheses. Collective Volume 1 Wiley: New York 1941. p. 222) yielded 56% I, m. 290-306°. Three other routes to I failed but produced new compounds 2,3-Dibromo-5-nitro-p-xylene (from nitration of 2-bromo-p-xylene with fuming HNO3 and bromination at 0° of the 5-nitro derivative in concentrated H2SO4 in the presence of Ag2SO4) was reduced in 90% EtOH with Fe powder and HCl yielding 94% 5-amino-2,3-dibromo-p-xylene (V), m. 87-9° (EtOH-H2O). V diazotized at 0°, reduced with 50% H3PO2 (added dropwise at -2°), left 18 hrs. in a refrigerator, and the oil which separated taken up in C6H6 and fractionated, yielded 85% 2,3-dibromo-p-xylene (VI), b16 139-44°, m. 16-17°. Since VI with BuLi and CO2 failed to give the corresponding carboxylic acid, apparently a stable Li compound could not be formed for a synthesis of I parallel to that of II. 2-Acetamido-p-xylene nitrated, refluxed with concentrated HCl, and steam distilled yielded 10% 2-amino-3-nitro-p-xylene (VII), m. 29-32°, from the distillate and 52% 5-nitro isomer (VIII), m. 142-3°, from the residue. The structures of VII and VIII are evident from their N.M.R. spectra. VIII brominated in AcOH at 40° yielded 75% 2-amino-3-bromo-5-nitro-p-xylene (Blanksma CA 7: 1492) which was diazotized by Schoutissen’s method (CA 28: 1215), treated with KI in H2O, warmed to 45°, NaHSO3 added, and the product recrystallized from EtOH-H2O yielding 85% 3-bromo-2-iodo-5-nitro-p-xylene (IX), m. 107-8°. A biphenyl derivative could not be obtained from IX by Ullman coupling. 3,6-Dimethylphthalic anhydride (from the Diels-Alder adduct between 2,5-dimethylfuran and maleic anhydride) heated 2-3 hrs. over a free flame with concentrated NH4OH yielded 97% 3,6-dimethylphathalimide (X), m. 227-8° (MeOH-H2O). X should give IV with NaOH solution and hypobromite, but only the anhydride resulted. N.M.R. values are recorded for all compounds This study involved multiple reactions and reactants, such as 4,7-Dimethylindoline-2,3-dione (cas: 15540-90-6Formula: C10H9NO2).
4,7-Dimethylindoline-2,3-dione (cas: 15540-90-6) belongs to indole derivatives. In addition to tryptophan, indigo, and indoleacetic acid, numerous compounds obtainable from plant or animal sources contain the indole molecular structure. It is used in perfumery and in making tryptophan, an essential amino acid, and indoleacetic acid (heteroauxin), a hormone that promotes the development of roots in plant cuttings.Formula: C10H9NO2
Referemce:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles