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Please login to access the full content or check if you have access via19.7.1.1.5.2 Variation 2: With Trichloromethyl Chloroformate (Diphosgene)
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Suginome, M.; Ito, Y., Science of Synthesis, (2004) 19, 457.
Trichloromethyl chloroformate (diphosgene) is a safer alternative to phosgene and is similarly effective for the dehydration of N-substituted formamides in the synthesis of isocyanides 30.[43] In many cases, higher yields have been achieved with the diphosgene method than with the phosgene method. Preparations of some selected isocyanides are summarized in Scheme 19. For the synthesis of isocyanides from optically active amino acid derivatives, the use of 4-methylmorpholine as a base is recommended to avoid racemization.
Meeeee 88 Meeeeeeee ee Meeeeeeeeee ee eee Meeeeeee eee Meeeeeeeeeeeeee Meeeeeeeeeeee Meeeeee[88]
M8 | Meeee (%) | Mee | |
---|---|---|---|
Meeeeeeeeeeeeee Meeeeeeeeeeeee | Meeeeeee | ||
Me | 88e | 88 | [88] |
e-Me | 88e | 88 | [88] |
Me | 88 | 88 | [88] |
Me | 88 | 88 | [88] |
8-MeMM8M8 | 88 | 88 | [88] |
MM8MM8Me | 88 | 88 | [88] |
MMMeMMMMMMMeMM8Me | 88e | 88 | [88] |
e Me8M eee MM8Me8 eeee eeee ee −88°M eeeeee eeeeeeeee eeeeee.
e Meee: Me8M, eeeeeee: 8,8-eeeeeeeeeeeeeee. Mee eeeeeeee eee eeeeeeee eeee eee MM8.
e Meeeeee: 8,8-eeeeeeeeeeeeeee.
e Meee: 8-eeeeeeeeeeeeeeee.
Mee eeeeeeeeee eeeeee eee eeee ee eeeeeee ee eee eeeeeeeee ee 8,8-eeeeeeeeeeeeeeeee eeeeeeeeeee 88 eeee eee eeeeeeeeeeeee eeeeeeeeeeee 88 (Meeeee 88).[88]
Meeeee 88 Meeeeeeee ee 8,8-Meeeeeeeeeeeeeeeee[88]
Meeeeeeeeeee Meeeeeeee
Meeeeeeeeee 88 Meeee Meeeeeeeee; Meeeeee Meeeeeeee:[88]
MMMMMMM: Meeeeeeeeeeeeee eeeeeeeeeeeee (eeeeeeeeee) eee eeeeeeee eeeeeeee ee eeeeeeeeee ee eeeeeeeeeeeee.
M eeee ee eeeeeeeeeeeeeee eeeeeeeeeeeee (8.88 eM, 8.88 e, 88 eeee) ee eee MM8Me8 ee 8°M eee eeeee, eeee eeeeeeee, eeee 8 e ee e eeee ee ee M-eeeeeeeeeeeeeee eeeeeeeee (8.88 eee) eee eeeee Me8M (88 eM, 8.88 eee) ee eee MM8Me8 (888 eM) eeeeee ee −88°M. Meeee eeeeeeee eee 88–88 eee, eee eeeeeeeeeee eee eeeeeee ee eeee ee 88°M eee eee eeee eee eeeeeeeee eeee M8M (88 eM) eee 8.8% ee MeMMM8. Mee eeeeeee eeeee eee eeeeeeeee eee eeeee. Meeeeeeeeee ee eee eeeeeeee eeeeeeee ee eeeeeeeeeeee ee eeeeeeeeeeeeeeeee eeeeeeee eee eeeeeeeeeeeee eeeeeeeeee.
8,8-Meeeeeeeee-8,8-eeeeeeeeeeeeeee (88, M8 = M8 = Me); Meeeeee Meeeeeeee:[88]
M eeee ee eeeeeeeeeeeeeee eeeeeeeeeeeee (8.8 eM, 88 eeee) ee MM8Me8 (88 eM) eee eeeee ee e eeeeeee eeeeeee ee (8,8-eeeeeeee-8,8-eeeeeeeee)eeeeeeeeeee (88, M8 = M8 = Me; 8.88 e, 88.8 eeee) eee Me8M (8.8 eM, 88 eeee) ee MM8Me8 (8 eM) eeee 88 eee ee −88°M. Mee eeeeeee eee eeeeeeeee eeeeee ee 8°M eeeeeeeee eeee eeeeeeee eee eeee eeeeee ee −88°M. Mee-eeee 88% ee Me8MM8 (88 eM) eee eeeee eeeeeeee ee eee eeeeeee, eeeee eee eeee eeeeee ee ee. Mee eeeeeee eeeee eee eeeeeeeee, eeeeeeeee eeee eee-eeee 88% ee Me8MM8, eee eeeee (MeMM8). Mee eeeeeee eee eeeeeeeeee eee eee eeeee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee (Meeeeeee, eeeeee/MM8Me8 8:8) ee eeee e eeeeee eeeee; eeeee: 8.88 e (88%); ee 888–888°M (eee).
References
[43] | Meeeee, M.; Mee, M., Meeee. Meee., (8888) 88, 888; Meeee. Meee. Mee. Me. Meee., (8888) 88, 888. |
[44] | Mee, M.; Meeeeee, M.; Meeeee, M.; Meeeeeee, M., Meeeeeeee, (8888), 888. |