The following will be conducted in few weeks as the timetable forbids, so to say.. The synth is following the writeup found at
https://www.thevespiary.org/rhodium/Rhodium/chemistry/mda.txt
I let you know the yields
... and all comments/suggestions are welcome!
STEP 1 (Makin' da nitroalkene)
Dissolve 500g (2.05mol, 245.07g/mol) of 4-bromo-2,5-dimethoxybenzaldehyde into 154g (2.05mol, 75.067g/mol, Density: 1.045) of nitroethane containing 33g of cyclohexylamine and let the mix stand for about 3 weeks... Then, crush your nitroalkene cake and wash it with about liter of freezer cold MeOH. Spread to dry...
Supposed YIELD: ABOUT 500-550g of 4-bromo-2,5-dimethoxyphenyl-2-nitropropene (288.095g/mol)
STEP 2 (Reducin' da above mentioned stuff with AlH3)...
To 250 g of LiAlH4 dissolved in 3,5 L of ice cold anhydrous THF or in 2L of anhydrous diethyl ether, add dropwise with cooling and stirring and to this, 48ml of 100% H2SO4 (keep under 0'C!). To the reducing solution, add 500-550 g of 4-Br-2,5-DiMeOP-2-NP (straight from the previous step) dissolved in 1 L of anhydrous THF or diethyl ether... The addition should take around 4 hours with proper cooling (keeping below 0'C) of the reaction mix...
Stir at room temperature for 48 hours... (NO REFLUX!) Check the completion of the reaction with TLC...
Then, add to the mix containing the now reduced compound, 1000 ml of IPA to decompose the residual AlH3... followed by 400 ml of ~20% aqueous NaOH... (100g NaOH)
Filter the solids (Al + Li salts) from the reaction mix and CAREFULLY wash the filter cake using first some THF and then with IPA...
Evaporate the solvents and (preferably distill the oil) gas the free base in anhydrous IPA with HCl or add 1:1/mol 85% phosphoric acid to get the monobasic phosphate.
Afterwork: Wash the salt with anhydrous Et2O and recrystallize from boiling IPA.