Benzaldehyde, 2,3-dimethoxy complexes

To a solution of 10 g impure 2,5-dimethoxy-(t-butylthio)benzaldehyde in 75 mL of nitromethane there was added 1.0 g of anhydrous ammonium acetate, and the mixture was heated on the steam bath 1.5 h. Removal of the excess solvent/ reagent under vacuum produced an orange oil that was (not surprisingly) complex by TLC and which would not crystallize. A hot hexane solution of this oil was allowed to slowly cool and stand at room temperature for several days, yielding a mixture of yellow crystals and a brown viscous syrup. The solids were separated and recrystallized from 40 mL MeOH to give 3.7 g 2,5-dimethoxy-4-(t)-butylthio-B-nitrostyrenc as fine lemon-yellow crystals, with a mp of93-94 °C. A second crop... 

N]04Ci,H2, Benzaldehyde, 2,3-dimethoxy-, 5-(a-methylbenzyl)semioxamazone, chromium complexes, 23 88 Nj04C H2, Benzaldehyde, 3,4-dimethoxy-, 5-(ot-methylbenzyl)semioxamazone, chromium complexes, 23 88 N305C,Hi3, Cytidine, palladium(II) complexes, 23 54 N30,3PrC8H,6, Praseodymium Ill), trini-... 

An alternative approach toward the vancomycin AB system was described by Wilhelm and Widdowson in a synthesis of the cnt-actinoidinic acid derivative 118 (Scheme 21) [60]. These authors start from 3,5-dimethoxy benzaldehyde (112) to prepare first complex 113. The latter serves as a substrate for an enantio-... 

To a solution of 10 g impure 2,5-dimethoxy-(t-butylthio)benzaldehyde in 75 mL of nitromethane there was added 1.0 g of anhydrous ammonium acetate, and the mixture was heated on the steam bath 1.5 h. Removal of the excess solvent/reagent under vacuum produced an orange oil that was (not surprisingly) complex by TLC and which would not crystallize. 

In the presence of water-soluble cobalt phthalocyaninetetra(sodium sulfonate) (CoPcTS), 3,4-dimethoxybenzyl alcohol (a lignin model) is catalytically oxidized by dioxygen to 3,4-dimethoxy-benzaldehyde" ". Typical reaction conditions are 1 atm O2 and 85°C, 12 hours at pH 11, yield 100%.The product yield decreases with decreasing pH it is 84% at pH 10 and 18% at pH 8. A cationic latex particles had little effect on the yield or rate of oxidations. PcTS complexes of Fe(II), Cu(II) and Ni(II) gave less than 1% yield under comparable conditions. 

Scheme 5.6 outlines the stereoselective approach to the enantiopure, planar chiral key intermediates, 2-bromo-3,5-dimethoxy-benzaldehyde Cr(CO)3 complexes (+)-9 and (—)-9, as planar chiral coupling partners [50]. The elegance of... 

Reactions of the anions (L) of Schiff bases from 5 -a-amino acids and cinnamic aldehyde or 4-methoxy or 2,4-dimethoxy benzaldehyde with [Cp RhCl2]2 gave the (N,0) chelate complexes ds/trans Cp RhCl(L). The complex Cp RhCl[02CCH(CHMe2)N=CH-CH=CHPh] 136 was formed with a high diastereoisomeric excess (9/1). ... 

---