Preparation of 3-Ethoxy-B-nitrostyrene

A solution of 8.5 parts of potassium hydroxide in 27 parts of methanol is added during 30 minutes to a stirred solution of 50 parts of 3-ethoxybenzaldehyde in a mixture of 24 parts of nitromethane and 55 parts of ethanol at 5°C. The mixture is stirred for 15 minutes and a solution of 6.8 parts of sodium hydroxide in 33.5 parts of water is then added during 15 minutes at less than 10°C. The mixture is stirred for a further 30 minutes and is then poured into 350 parts of ice-cold water. The aqueous solution thus obtained is poured with stirring into a solution of 196 parts of concentrated hydrochloric acid in 235 parts of water. The mixture is filtered and the solid residue is crystallised from ethanol. There is thus obtained 3-ethoxy-B-nitrostyrene, m.p. 104— 105°C. Source Imperial Chemical Industries Limited 1966 

A solution consisting of 25 g of 2,4-dimethoxybenzaldchydc (Aldrich) in 200 mL. of nitroethane was treated with 0.5 g anhydrous ammonium acetate and held on a steam bath for 12 hours. The solvent was removed in vacuo from the mixture yielding 22.3 g of yellow crystals, m.p. 80°-81 ° C., upon cooling in 50 ml of methanol. 

A mixture of 31.6 g. of 2,5-dimethoxy-4-methylbenzaldehyde, 20.2 mL. of 1-nitropropane, 6 mL. cyclohexylamine, and 50 mL. benzene is kept at reflux in a Dean Stark apparatus for 24 hours. Cooling results in tbe spontaneous crystallization of an orange product wbicb on filtration and drying weighs 14.9 g. Recrystallization from methanol yields the product 2-nitro-(2,5-dimethoxy-4-methylphenyl)-butene-l as an orange crystalline material, mp. 115°C. Source Shulgin 1976 

To a solution of 144 g of protocatechualdehyde in 3000 mL. of nitroethane, heated to about 90°C, 14 g. of ammonium acetate are gradually added, the the mixture is heated at 100°C for 3 hours The excess nitroethane is then distilled off. The residue is l-(3,4-dihydroxy-phenyl)-2-nitroproplene, m.p. 148—149°C. Yield 192 g (94%). 

The contents of the still-pot are then transferred to a beaker (heating gently to melt, if necessary), cooled in an ice-salt mixture to crystallize, filtered, and drained. Melting point, of crude crystals 57-60 C., after recrystallization from ethanol-water or petroleum ether ethyl ether 67° C. Source Bruce 1952 

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