MDP2P from Piperonalby Karel
Here is announced experimental from JOC 221 (1951):
In a 5-liter 3-necked flask equipped with a stirrer and reflux condenser were placed 1000 cc. of ethanol and 110 g of beta-nitroisoeugenol. The mixture was heated with stirring and, when the nitroisoeugenol was dissolved, 2500 cc. of hot water was added. With heating and vigorous stirring, 200 g of reduced iron powder and 8 g of hydrated ferric chloride were added. With continued stirring 100 cc. of concentrated hydrochloric acid was added slowly. The hydrochloric acid caused a violent reaction which subsided after about 5 minutes; the mixture was refluxed with stirring for two hours and then distilled under reduced pressure until approximately 2 liters of distillate was collected. The residue was filtered, and the fluffy iron oxide was washed thoroughly with hot water and then with ether. The combined filtrate and washings were acidified strongly with hydrochloric acid and extracted with ether. The ether was dried and distilled to yield a light oil which was fractionated in vacuo to give 68 g of vanillyl methyl ketone boiling at 126-127 C at 0.3 mm (72 % yield).
3,4-Dimethoxyphenylacetone and 3,4-methylenedioxyphenylacetone were prepared from the corresponding beta-nitropropenylbenzenes by almost identical procedures with 90 and 72 % yield.
For preparation of 2-MeO-P2P with toluene/water as solvent see Organic Syntheses, Coll. vol. 4, p. 573.
My modification of this preparation:
In a 2-liter 3-necked flask equipped with a stirrer and reflux condenser were placed 460 ml of ethanol (1) and 67 g of beta-nitroisosafrole (2). The mixture was heated with stirring and, when the yellow crystals were dissolved, 1100 ml of hot water was added. With heating and vigorous stirring, 80 g of reduced iron powder (3) and 5 g FeCl3+6H2O were added. With continued stirring 63 ml conc. HCl was added in 30 min. The mixture was refluxed with stirring for 2 h and then distilled under atmospheric pressure (4). The residue was filtered and brown iron oxide was extracted 3 x 50 ml CH2Cl2. Filtrate and organic washings were acidified with HCl and red ketone layer was collected. Light green water layer was extracted 2 x 100 ml CH2Cl2. The combined extracts were dried with Na2SO4 and distilled at atmospheric pressure (80 C bath). Dichloromethane was completely removed in vacuo to give 55 g of crude MDP2P as deep red oil which was used for CH3NH2/Al reaction.