Methylene-dihydroxybenzaldehyde

DIOXYMETHYLENE-PROTOCATECHUIC ALDEHYDE HELIOTROPIN 3,4-METHYLENE-DIHYDROXYBENZALDEHYDE 3,4-... 

Heliotropin 3,4-Methylene dihydroxybenzaldehyde 3,4-Methylenedioxybenzaldehyde 3,4-Methyleneprotocatechuic aldehyde Piperonal Piperonaldehyde Piperonyl aldehyde Protocatechuic aldehyde methylene ether Classification Diazo dye organic compd. 

A similar reaction is the methylenation of 3,4-dihydroxybenzaldehyde in the presence of a phase-transfer catalyst on a benign calcium carbonate surface [26]. Presumably, bonding of the vicinal hydroxyl groups is low thereby enhancing the reaction with the alkylating agent under the action of solvent-free microwave irradiation (Eq. 15). 

Dissolve 4 g 3,4-dihydroxybenzaldehyde (or any other ben-zaldehyde having adjacent OH groups) and 7.6 g KOH in 50 ml water. Heat to 50° (under N2 if possible) with stirring and add 5 g methylene sulfate stir and heat two hours. Add 500 ml water and sufficient K sulfate to dissolve the precipitate. Extract with ether, acidify the aqueous phase with HCI to precipitate unreacted aldehyde, and dry, evaporate in vacuum the ether to get the title compounds (recrystallize-methanol). 

From Catechol. Several routes have recently been developed for the synthesis of heliotropin from catechol. In one such route, catechol is converted into 3,4-dihydroxymandelic acid with glyoxylic acid in an alkaline medium in the presence of aluminum oxide. 3,4-Dihydroxymandelic acid is oxidized to the corresponding keto acid (e.g. with copper-(II) oxide), which is decarboxylated to 3,4-dihydroxybenzaldehyde [176]. The latter product is converted into heliotropin, for example, by reaction with methylene chloride in the presence of quaternary ammonium salts [177]. 

To asolution of 11.7 g 3-bromo-4,5-dihydroxybenzaldehyde in 36 mL DMSO there was added 29 g methylene iodide followed by 20.8 g anhydrous K2COr This was heated on the steam bath for 3 h, added to 1 L H,0, made strongly basic with NaOH, then extracted with 3x100 mL CH2C1,. These extracts were pooled, washed with H.O, and the solvent removed under vacuum. The dark brown semi-solid residue was distilled with the major fraction (6.0 g) coming over at 120-130 °C at 0.3 mm/Hg. This, upon recrystallization from 35 g boiling MeOH, gave 1.3 g of 3-bromo-4,5-methylenedioxy-benzaldehyde as an off white crystalline solid with a mp of 123-124 °C. 

SYNS 3,4-BENZODIOXOLE 5-CARBOXALDEHYDE 3,4-DIHYDROXYBENZALDEHYDE METHYLENE KETAL DIOX i METHYLENE-PROTOCATECHUIC ALDEHYDE FEMANo. 2911 HELIOTROPIN 3,4-METH iTENE-DIHYDROXYBENZALDEHYDE 3,4-METHYLENEDIOXYBENZALDEHYDE PIPERON-ALDEHYDE PIPERONYL ALDEHYDE PROTO-CATECHUIC ALDEHYDE METHYLENE ETHER... 

Synonyms 1,3-Benzodioxole-5-carboxaldehyde 3,4-Benzodioxole-5-carboxaldehyde 3,4-Dihydroxybenzaldehyde methylene ketal Dioxymethyleneprotocatechuic aldehyde Formaldehyde protechualdehyde-3,4-cyclic acetal... 

Based on AA oxidation to dehydroascorbic acid in acidic medium using iodine-iodide solution as oxidizing reagent. The iodine amount consumed in the redox reaction was detected Electrocatalysis of AA on a glassy carbon electrode chemically modified with polyaniline films AA was determined at a vitreous C electrode modified with 3,4-dihydroxybenzaldehyde AA was determined with a chemically modified with methylene green (electron mediator) carbon paste electrode... 

Pyridinecarboxylic acid [ 2,3-dihydroxyphenyf)methylene] hydrazide, 9CI. (x-Picolinic acid resorcinolhy dr azide. 2,3-Dihydroxybenzaldehyde 2-pyridinecarbonylhydrazone [40522-21-2]... 

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