Post 258096 (https://www.thevespiary.org/talk/index.php?topic=12309.msg25809600#msg25809600)
(Rhodium: "Safrole to MDMA via isocyanates?", Serious Chemistry) where Rhodium had the same idea, but to make a methylamine.Post 442105 (https://www.thevespiary.org/talk/index.php?topic=9038.msg44210500#msg44210500)
(DRIVEN: "NaOCN from urea and sodium carbonate", Methods Discourse) for making 4-MAR.Post 445115 (https://www.thevespiary.org/talk/index.php?topic=9038.msg44511500#msg44511500)
(Polverone: "More cyanate info", Methods Discourse) on cyanates and Bandil's postPost 354295 (https://www.thevespiary.org/talk/index.php?topic=9285.msg35429500#msg35429500)
(Bandil: "trans-4-MAR synth w/o cyanogenbromide writeup!", Methods Discourse) suggest that cyanates might persist long enough in aqueous solution to make use of phase-transfer catalysis techniques. Perhaps if the aqueous phase is buffered with something noncompetitive like sodium acetate. Otherwise, just stirring NaOCN with haloalkane might do the trick. (eventually)
Reactant : potassium isocyanate, i-propyl halide
Product : isocyano-acetic acid isopropyl ester
Yield : 92 percent
Solvent : dimethylformamide
Time : 3 hour(s)
Temperature : 55 - 60 °C
Suzuki, Mamoru et al; Chem. Pharm. Bull. EN, 28, 8, (1980) 2374-2383
Reactants: 4-phenoxy-benzoyl chloride ; sodium cyanate
Product: 4-phenoxy-benzoyl isocyanate
Yield: 76 percent (BRN=5022396)
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 2 hour(s)
Other Conditions: Heating
Reactants: propionyl chloride ; sodium cyanate
Product: propionyl isocyanate
Yield: 52 percent
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 8 hour(s)
Temperature: 80°C
Reactants: 3-chloro-benzoyl chloride ; sodium cyanate
Product: 3-chloro-benzoyl isocyanate
Yield: 81 percent
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 2 hour(s)
Other Conditions: Heating
Reactants: 2-chloro-benzoyl chloride ; sodium cyanate
Product: o-chlorobenzoyl isocyanate
Yield: 80 percent
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 2 hour(s)
Other Conditions: Heating
Reactants: 3-methoxy-benzoyl chloride ; sodium cyanate
Product: 3-methoxy-benzoyl isocyanate
Yield: 78 percent
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 2 hour(s)
Other Conditions: Heating
Reactants: sodium cyanate ; benzoyl chloride
Product: benzoyl isocyanate
Yield: 83 percent
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 2 hour(s)
Other Conditions: Heating
Reactants: 4-methyl-benzoyl chloride ; sodium cyanate
Product: 4-methyl-benzoyl isocyanate
Yield: 81 percent
Catalyst: SnCl4
Solvent: 1,2-dichloro-benzene
Time: 2 hour(s)
Other Conditions: Heating
Reactants: 2-ethyl-2-bromo-butyryl bromide ; mercury (I)-cyanate
Product: 2-ethyl-2-bromo-butyryl isocyanate
Patent DE271682 (http://l2.espacenet.com/dips/viewer?PN=DE271682&CY=gb&LG=en&DB=EPD)
Reactants: sodium cyanate ; (3-bromo-propoxy)-benzene
Product: (3-isocyanato-propoxy)-benzene
Solvent: dimethylformamide
Time: 1 hour(s)
Other Conditions: Heating
isocyanate : yield
Phenyl 86%
1-Naphthyl 90%
Ethyl 78%
isothiocyanate: yield
Phenyl 96%
Allyl 81%
They use slightly more than equimolar amounts of LiAlH4 to reduce. The equation for reduction is suggested to be:
4 RNCO + 3 LiAlH4 --> LiAl[RNCH3]4 + 2 LiAlO2
With post-reaction hydrolysis yielding the free methylamines.
Experimental details:
The isocyanates were dissolved in 5x their weight of ether and dripped carefully into an ethereal solution of LiAlH4, then refluxed for 1.5 to 2 hours. The excess hydride was destroyed with water and 100-200 ml 30% NaOH solution was added and the whole shebang refluxed. It seems the LiAl salt was rather persistant and hard to hydrolyze.
Would MDMA survive being refluxed in 30% lye? Hmmm...that could be a problem.