O-Methoxybenzaldehyde

Data of Alves el al. (1978), in 20% ethanol. The intermolecular reference reaction is the general acid catalysed addition of phenylhydrazine to the methyl ether, calculated from feH,o using a = 0.35 and determined for the reaction with o-methoxybenzaldehyde (Bastos and do Amaral, 1979). The EM, which is in some doubt because of possible mechanistic complications, is determined by comparison of the rate constant given (dm3 mol-1 s 1) with the third order rate constant for the reference reaction... 

Dean and Stark water separator (Note 1), and a reflux condenser. To the flask are added in this order 200 ml. of reagent-grade toluene, 136 g. (1.0 mole) of o-methoxybenzaldehyde (Note 2), 90 g. (1.1 moles) of commercial nitroethane (Note 3), and 20 ml. of M-butylamine (Note 4). The solution is heated to produce a rapid reflux until the separation of water ceases (Note 5). The toluene solution is used directly in the next step (Note 6). 

SYNS 2-ANISALDEHYDE BENZALDEHYDE, 2-METHOXY-(9CI) o-METHOXYBENZALDEHYDE 2-METHOXYBENZALDEHYDE 6-METHOXY-BENZALDEHYDE 2-METHOXYBENZENE-CARBOXALDEHYDE SALICYLALDEHYDE METHYL ETHER... 

Similar azomethine ylides 48 are involved as key intermediates in the racemi-zation of optically active a-amino acids in the presence of a catalytic amount of aldehyde (83JOC843). Grigg confirmed this mechanism (83TL4457) and carried out the reactions of optically pure a-amino acids with salicyl- or o-methoxybenzaldehyde and maleic anhydride or N-phenylmaleimide in acetic acid. Cycloadducts of N-unsubstituted azomethine ylides 48 with dipolaropbiles were obtained only as racemates. These results indicate that the a-amino acids first produced the corresponding imine carboxylic acids with the retention of optical activity but these then undergo a tautomeric equilibration with N-protonated azomethine ylides 48 losing their optical purity. The ylides 48 were captured by several dipolaropbiles as racemic cycloadducts. As the imines of a-amino acids usually suffer spontaneous decarboxylation (as will be discussed later in Section (II,E), the formation of... 

By rcpeatingthe procedures described in Example 1 except thai 61 gofdiotliyl sulfate were used instead of 50 g of dimethyl sulfate, 53 g of 2-ethoxy-o-methoxybenzaldehyde having a melting point of 47° - 48 C were obtained (yield 97.5%). Anal. Found C, 66.58 H, 6.74. Calcd. ( 66.67 H, 6.67. Source Imai 1975... 

Tetrabromo-o-quinone o-N aphthoquinone 4-Chloro-l,2-Naphthoquinone 6-Bromo-l, 2-Naphthoquinone p-Tolualdehyde 14 1, anisaldehyde 14S) Acetaldehyde 8) Acetaldehyde , />-nitrobenzaldehyde 8> Benzaldehyde 1° ), m-tolualdehyde 1 ), p-tolualdehyde 10 ), o-methoxybenzaldehyde 10 1, anisaldehyde 106>, o-chlorobenzaldc-hyde 4 1... 

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