M-Hydroxy benzaldehyde

Slightly greater effects are observed for the B-bands of m-hydroxy-benzaldehyde and ra-nitrophenol (D, H-bond +68 and +96 A), although the nitro and formyl groups may not be terminal. Greater displacements should have been expected for the B-bands of o-hydroxy benzaldehyde and o-nitrophenol, but, owing to the formation of intramolecular hydrogen bonds by these derivatives (cf. below), an experimental confirmation is, unfortunately, not possible. 

A mixture of m-hydroxy-benzaldehyde, fused sodium propionate and of butyric anhydride was stirred and refluxed at heating. 

Isopelletierine (23) undergoes a Mannich reaction with both m-methoxy- and m-hydroxy-benzaldehyde, to give respectively a mixture of the cis (24 R = Me) and trans (25 R = Me) quinolizidines, and exclusively the tran -quinolizidine (25 R = H). The ratio of stereoisomers in the former reaction varies widely with solvent used. ... 

The thio analogue of 511 with R2 = H and Ar = m-hydroxyphenyl named dimethylenastron was prepared as a racemic mixture by the reaction of m-hydroxy benzaldehyde with 1 and thiourea in the presence of polyphosphate ester under MW irradiation. It has a distinct cell permeable inhibition of the mitotic Kinesin, Eg5 which was more potent than monastrol (05MI1173). 

Bromination of m-tolyl acetate in CC14 under irradiation by a 500 W lamp gives a 75 % yield of 3-acetoxybenzylidene bromide, which is converted in 70% yield into m-hydroxy-benzaldehyde by sodium formate in alcohol.431... 

In this equation, we find the different source and the selectivity between the two solutes, which can differ by the difference in energy of adsorption (Si° - 82°), molecular size (As2 - Asi), and secondary adsorption effect (Aeas)i - (Aeas)2- These considerations are valuable for a large number of compounds, but in the case of some isomers, the second terms of Eq. 13 can be considered practically equal to zero and only difference sources for selectivity remain in the difference in energy of adsorption and the secondary adsorption effect. The secondary adsorption effect plays a major role in the separation of the isomers. For instance, in adsorption on silica gel with benzene-pyridine (90 10, vol/vol) as eluent, the following Aeas values - 0.90 0.17 and + 0.05 0.11 for m-hydroxy-benzaldehyde and (9-hydroxybenzaldehyde, respectively. 

Scheme 31) [109]. 4-Chlorobutanal, cyclopropylaldehyde, and m-phenoxyl-benzaldehyde are also prepared in the two-phase system [110]. Indirect electrooxidation of 6y3-methyl-3y3, 5a-dihydroxy-16a, 17a-cyclohexanopregnan-20-one are indirectly electrooxidized to the corresponding 5a-hydroxy-3,20-dione using sodium bromide and substituted TEMPO as the mediating couple [111]. 

It is a liquid, m.p. — 4°, b.p. 245°, with a pleasant odor of white thorne flowers and is used in perfumes. It is interesting that while hydroxy benzaldehyde itself yields only one form of oxime the anis aldehyde yields the two stereo-isomeric forms. This is attributed to the influence of the free hydroxyl group in preventing the formation of isomers. In the anis aldehyde the hydroxyl group is converted into methoxy and the isomers are obtained. 

In place of SnCl2, HCI even iron powder and an organic acid like formic acid can be used. Meto-hydroxy benzaldehyde is then methylated with dimethyl sulfate in an alkaline medium to produce m-anisic aldehyde... 

This plant yielded V-methylpiperidine and girgensonine, C13H16ON2 (m.p. 144-146 or 147-148°, [a] 0° picrolonate, m.p. 192-194°), which proved to be iV-piperidyl-p-hydroxyphenylacetonitrile. Hydrolysis with alcoholic potash generated piperidine, hydrogen cyanide, and p-hydroxy-benzaldehyde. Its synthesis was accomplished by a recombination of these fragments (67). 

Chloro-l,3-dithian, obtained by the reaction of 1,3-dithian and A-chloro-succinimide, undergoes dissociation to chloride and dithianium ions in liquid SO2, as judged by the peak at 8 = 10.65 in the n.m.r. spectrum due to the 2-methine hydrogen. Reaction with phenol and iVA-dimethylaniline produced 2-(p-hydroxyphenyl)- and 2-(p-dimethylaminophenyl)-l,3-dithian, in 75 and 30% yield, respectively. The dithian derivatives of the o-hydroxy-benzaldehydes... 

N-Benzyl-hydroxy lamin 2 Zu2,42g(20 mMol) Benzaldehyd-oxim tropftman unter Riihren bei 0° 16m/ (32 mMol) 2 m Boran-Losung in abs. THF. Man riihrt 12 Stdn. bei 20 unter Stickstoff. engt i.Vak. ein, versetzt bei 0° mit 10 ml 20%iger Salzsaure, erhitzt 1 Stde. unter RiickfluB und stellt bei 0° mit 10%iger Kalilauge alkalisch. Die Mischung wird 90 Stdn. mit Pentan kontinuierlich extrahiert, im Stickstoff-Strom eingeengt und der Riick-stand bei 20°/0,2 Torr sublimiert Ausbeute 1,28 g (52% d.Th.) F 57°. 

---