Reference

Azo dyes

Azo dyes. Leverenz, Klaus (Bayer A.-G., Ger.). Ger. Offen. DE 2516031 28 Oct 1976, 15 pp. (German). (Germany). CODEN: GWXXBX. CLASS: IC: C09B041-00. APPLICATION: DE 75-2516031 12 Apr 1975. DOCUMENT TYPE: Patent CA Section: 40 (Dyes, Fluorescent Whitening Agents, and Photosensitizers) Azo dyes (I, R = NO2, CN; R1 = Et, Pr), blue dyes for polyester fibers, were prepd. by diazotization of 2,6-dibromo-4-nitroaniline [827-94-1] or 2,4-dinitro-6-bromoaniline [1817-73-8] in tetrahydrothiophene 1,1-dioxide [126-33-0] using nitrosylsulfuric acid, coupling with 3-AcNHC6H4NR12 in a polar aprotic solvent such as DMF [68-12-2] in the presence of a nonaq. base, and treating the unisolated bromoazo deriv. with CuCN and optionally zinc cyanide.Except for chemicals metioned above, 56532-53-7 and 126-33-0 are also used. .

The first total synthesis of (R)-convolutamydine A

All Rights Reserved. The first total synthesis of (R)-convolutamydine A. Luppi, Gianluigi; Monari, Magda; Correa, Rodrigo J.; Violante, Flavio de A.; Pinto, Angelo C.; Kaptein, Bernard; Broxterman, Quirinus B.; Garden, Simon J.; Tomasini, Claudia (Dipartimento di Chimica 'G.There are some reagents with their cas registry numbers 865155-18-6 and 827-94-1 are used in this study. Ciamician'-Alma Mater Studiorum, Universita di Bologna, Bologna 40126, Italy). Tetrahedron, 62(51), 12017-12024 (English) 2006 Elsevier Ltd. CODEN: TETRAB. ISSN: 0040-4020. DOCUMENT TYPE: Journal CA Section: 31 (Alkaloids) Section cross-reference(s): 22, 75 The first total synthesis of (R)-convolutamydine A (I) has been achieved by the organocatalytic addn. of acetone to 4,6-dibromoisatin. The abs. configuration was detd. by single crystal X-ray diffraction. DFT studies were used to model the transition states for the aldol reaction and equil. geometries of the post-aldol reaction intermediates. The DFT study revealed that the aldol bond forming reaction was considerably endothermic. .