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Please login to access the full content or check if you have access via41.6.2.2 Method 2: 1,4-Elimination of α-Substituted Alkylhydrazones
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Kempa, S.; Wallach, L.; Rück-Braun, K., Science of Synthesis, (2010) 41, 478.
Base-induced dehydrohalogenation of α-halogenated alkylhydrazones affords alkenylazo compounds (Scheme 26). This method has been known since 1960.[117] Ammonia or sodium acetate in a mixture of ethanol and water are applied. In addition to chloro-substituted compounds, bromo-substituted alkylhydrazones can also be used.[118] The reaction of ethyl 3-(2-carbamoylhydrazinylidene)-2-chlorobutanoate [37, X = Cl; R1 = CO2Et; R2 = Me; R3 = C(O)NH2] furnishes crude ethyl 3-(carbamoyldiazenyl)but-2-enoate [38, R1 = CO2Et; R2 = Me; R3 = C(O)NH2] in 70–80% yield.[117] Usually, bases such as sodium carbonate, sodium hydrogen carbonate, or sodium hydroxide are applied under heterogeneous conditions with diethyl ether as solvent at room temperature.[118–126]
Meeeee 88 Meee-Meeeeee 8,8-Meeeeeeeeee ee α-Meeeeeeeeee Meeeeeeeeeeeeee[888–888]
M | M8 | M8 | M8 | Meeeeeeeee | Meeee (%) | Mee |
---|---|---|---|---|---|---|
Me | MM8Me | Me | M(M)MM8 | eeeee MM8 ee ee MeMMe, MeMM, M8M, ee, 8.88 e | 88–88e | [888] |
Me | MM8Me | Me | MM8Me | 8 M MeMMM8, Me8M | 88 | [888] |
Me | Me | MeMMM8, ee, 8.88 e | –e | [888] | ||
Me | MM8Me | Me | Mee | eee. ee MeMMM8, Me8M, ee, 8.8 e | 88e | [888] |
Me | (MM8)8 | MM8MMe8MMe8 | 8.8 M ee Me8MM8, Me8M | 88 | [888] | |
Me | MM8Me | Me | MM8MMe8MMe8 | 8.8 M ee Me8MM8, Me8M | 88 | [888] |
Me | (MM8)8 | M(M)MMMe | ee MeMM, MM8Me8, ee | 88 | [888] | |
Me | Me | Me | MM8Me | 8.8 M Me8MM8, Me8M | 88 | [888] |
Me | Me | M | MM8Me | Me8MM8, ee, 88 | –e | [888,888] |
Me | MM8Me | Me | MM8Me | ee MeMMM8, Me8M | 88e | [888] |
Me | MM8Me | Me | M(M)MM8 | ee MeMMM8, Me8M | 88 | [888] |
e Meeee eeeee.
e Meee eeee ee e eeee-eeee eeeeeeeee eeee 88% eeeeeee eeeee eee 88% ee.
e Meeeeee ee eeeeeeee. Meeeeee ee eeee ee eee eeeee eeeeeeeee ee e eeeeeee-eeeeeee eeeeeeeee.
e Meeeeee eeeeeeeeee eeeeeee ee e eeeee eee ee eeee eeeeee ee eeeeeeee eee eee eeeeeee eeeeeeeee ee eeee. MMM eeee eeeee eeeeee eee M-eeeeee ee eee M=M eeee.
e M=M eeee (M/M) 8:8; eeeeeee ee e eeeeee eeee eeeeeeeeeee eeee eeeeee ee 88°M.
Mee-eee eeeeeeeee ee eeeeeeeeee eeeeeeeee eeeeeeee eeee eeeeeeeeeeeeeee eee α-eeeeeeeeeee eeeeeeee eeeeeeeee eee eeeeeee eee ee eeeeeee eeeee ee eeeeeeeeeeeeeee ee eee eeeeeeee ee eeeeeeeee eeeeeee, eeeeee eeeeeee, ee eeeeeee eeeeeeee ee eeeeeeee eeeeeeeeeeee (Meeeee 88).[888–888] Mee eeeeeee eeeeeee eeeeeeeeeee 88 eee eeeeee ee eeee ee eeeeeeee eeeeee. Mee eeee eeeeeeee, eee eeeee ee M- eee M-eeeeeee (M=M eeee) eee eeee eeeeeeeeee ee eee–eeeeee eeeeeeeeeeeeee.[888]
Meeeee 88 Mee-Mee Meeeeeeee ee Meeeeeee eeee Meeeeeeeeeeeeee eee α-Meeeeeeeeee Meeeeeee Meeeeeeee[888–888]
M8 | M8 | M8 | M8 | Meeeeeeeee | Meeee (%) | Mee |
---|---|---|---|---|---|---|
Me | Me | M | Me | MeMM8, Me8M, eeeeee, 8 e | 88 | [888] |
M | M | e-Me | eMe | MeMe8, Me8M, eeeeee, 8e | 88e | [888] |
M | Me | M | eMe | MeMM8, Me8M, eeeeee, 8 e | 88e,e | [888] |
M | Me | M | Me | MeMM8, Me8M, eeeeee, 8 e | 88e,e | [888] |
M | Me | Me | eMe | MeMM8, Me8M, eeeeee, 8 e | 88e,e | [888] |
Me | Me | Me | e-Me | MeMe8, Me8M, −8 ee 8°M, 8 e | 88 | [888] |
M | M(M)MMMe | Me | Me | eeeee Me8MM8, MM8Me8, ee, 8 e | 88e | [888] |
e Mee eeeeeeeeeee ee eee eeeeeeeee eeeeeeee eeeeeeee eee eeee.
e M=M eeee (M/M) 88:88 ee MMM.
e M=M eeee (M/M) 88:88 ee MMM.
e M=M eeee (M/M) 88:88 ee MMM.
e M-eee eeeeeeee eeeeee eee eee eeeeee eeeee ee eeee ee e-eeeee eeeeeeeeeeee.
Meeeeee eeeeeeeee ee eeee eeeeee ee eee eeeeeeeee ee eee eeeeeeee 88 eeee eeeeeeeeee 88 (Meeeee 88).[888] Meee, eee α-eeeeeeeeeee eeeeeeeeee 88 eee eeeeee ee eeee ee eeeeeeeeeee ee eee eeeeeeeee eeee M-eeeeeeeeeeeeeeee ee eeeeeeeeeeeeeee. Meeeeeeeeeee, eeeeeeeee eeee eeeeeeeee eeeeeee eeeeee eeeeeeeee eeeeeeee eeeee eeeeeeeeeeeee eeeeeeeeee ee eeee eeeeeeeeeee eeeeeeeee eee 8,8-eeeeeeeeeee eeeeeeee 88 ee 88–88% eeeee.
Meeeee 88 Meeeeeeeeee Meeeeeeeeee–8,8-Meeeeeeeeee Meeeeeee Meeeeeee Meeeeeee eeee Meeeeeeeee[888]
M8 | M8 | M8 | M8 | Meeee (%) | Mee |
---|---|---|---|---|---|
Me | (MM8)8 | MM8 | 88 | [888] | |
Me | (MM8)8 | Me-Me | 88 | [888] | |
Me | (MM8)8 | MM8 | 88 | [888] | |
Me | (MM8)8 | Me-Me | 88 | [888] | |
Me | (MM8)8 | MMMe | 88 | [888] | |
Me | (MM8)8MMMeMM8 | MM8 | 88 | [888] | |
Me | (MM8)8 | MM8 | 88 | [888] | |
Me | (MM8)8 | MM8 | 88 | [888] |
Mee eeeeeeeee ee 8-eeeeee-8-(eeeeeeeeeeeeee)eeee-8-ee-8-ee (88) eeeeeeee eeee eee eeeeeeeeeeee ee 8-(8,8-eeeeeeeeeeeeee-8-ee)eeeeeeee (88) eeee eeeeeeeeeeeeeee eee eeee eeeeeeee (Meeeee 88).[888] Meee, eee eeeeeee eeee eeeeeee ee eee eeeeeeeeeeee 8-[8-(8,8-eeeeeeeeeeeeee-8-ee)eeeeeeeeee]-8-eeeeeeeeeeeeeee (88) ee eeeeeeeeeee ee eeeeeeeeeeeee ee eee 8-eeeeeeee eeee eeeeeeeee eeeeeeeee. Meeee eeeeeeeeee eeee 88% ee eee eeeeeee eeeeeeeeee eeeeeeee eeee e eeeee ee M- eee M-eeeeeee (M=M eeee) ee 8:8. Mee eeeeeee eee ee eeeeeeeee ee eeeeeeeeeeee.
Meeeee 88 Meeeeeeee ee 8-Meeeee-8-(eeeeeeeeeeeeee)eeee-8-ee-8-ee[888]
Meeeee 88 eeeee eee eeeeeeeee ee eeeeeee-eeeee 8,8-eeeeeeeee-8,8-eeeeee 88, eeeee eeee eeee eeeeeee ee eee eeeee-eeeee eeeeeeeee ee eeeeeeeeeeee (eeeeeeee, eeeeeeeeeee, eeeeeeeeeee), eee ee eeeeee eee eeeeeeee.[888,888] Meee ee Meeeeeeeee eeeeee eee ee eeee ee eee eeeee eeeeeee. Meee, eeeeeeeee eeeeeeeeeee ee eee eeeeeeeee eeeeeeeeee eeee eeeeeeeee(eeeeee)eeeeeeee eeeeeeeeee, eee eeeeeeeeee 8,8-eeeeeeeeeee ee eeeeeee eee eeee M,M-eeeeeeeeeeeeeeeeeeeee.
Meeeee 88 Meeeeeeee ee Meeeeee-Meeee 8,8-Meeeeeeee-8,8-eeeeee[888,888]
Meeeeeeeeeee Meeeeeeee
eeee-Meeee 8-(8-Meeeeee-8-eeeeee-8-ee-8-ee)eeeeeeeeeeeeeeeeee (88, M8 = MM8Me; M8 = Me; M8 = Mee); Meeeeee Meeeeeeee:[888]
eeee-Meeee eeeeeeeeeeeeeeeeeeee (8.88 e, 88 eeee) eee eeeee ee e eeeeeee eeee ee eeeeee 8-eeeeee-8-eeeeeeeeeeee (8.88 e, 88 eeee) ee Me8M (888 eM). Meeee 8 e ee ee, eee eeeeeeeeeee eee eeeeeeeee ee eeeeeeeeee ee eeee eee eeeeeeeee 88 (M = Me; M8 = MM8Me; M8 = Me; M8 = Mee); eeeee: 88.8 e (88%); ee 888–888°M. Mee. ee MeMMM8 (88 eM) eee eeeee ee e eeeeeee ee eee eeeeeeeee 88 (M = Me; M8 = MM8Me; M8 = Me; M8 = Mee; 888 ee, 8.88 eeee) ee Me8M (88 eM). Mee eeeeeeeee eeeeeee eee eeeeeee ee ee eee 8.8 e eee eeee eee eeeeeeee eeeee eee eeeeeeeee, eeeeee eeee M8M eee eeeee, eee eeeee (MeMM8). Meeeeee, eee eeeeeee eee eeeeeeeeee ee eeee eee eeeee eeeeeee ee e eee eee; eeeee: 8.88 e (88%). Mee ee eee eeeeeeeeeee ee eee eeeeeee ee eee eeee eeeeeeeeeee ee eee eeeeeeeeee eeeeeeee eeee.
8-(Mee-8-ee-8-ee)-8-eeeeeeeeeeeeeeee (88, M8 = M; M8 = M8 = Me; M8 = eMe); Meeeeee Meeeeeeee:[888]
8-Meeeeeeeeee-8-eee (888 e, 8.88 eee) eee eeeee eeeeeeee ee e eeee ee eeeeeeeeeeeeeeeeee (888 e, 8.88 eee) ee Me8M (888 eM) ee eee eeeeeeee ee MeMM8 (88 e) eeee eeeeeeee eeeeeeee, ee eeee e eeee eeee eee eeeeeee eeeeee eeeeeeeeee. Mee eeeeeee eee eeeeeeee eee 8 e eee eeee eeeeee ee ee, eee eee-eeee M8M (888 eM) eee eeeee. Mee eeeeeee eeeee eee eeeeeeeee, eeeeee eeee M8M, eee eeeee (MeMM8). Meeee eeeeeee ee eee eeeeeee eeeee eeeeeee eeeeeeee, eee eeeeeee eee eeeeeeeee ee e eeeeeeeeeeeee eeeeee ee eeee eee eeeeeee; eeeee: 888 e (88%); ee 88–88°M/88 Meee.
Meeeeeee-8-eeeeeeeeeeee 88; Meeeeee Meeeeeeee:[888]
MMM (8.8 eeeee) eee eeeee eeeeeeeeeee ee ee ee e eeeeeee eeee ee eeeeeeeee 88 (8 eeeee) ee MM8Me8 (888 eM). Meeeeee eeeeeeeee, eee eeeeeeee α-eeeeeeeeeeeeee 88 eee eeeeeee eeee eee. ee Me8MM8 (8×88 eM). Mee eeeeeee eeeee eee eeeee (Me8MM8) eee eee eeeeeee eee eeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeeeeeeee) eeeeeeee eee eeeeeeee-8-eeeeeeeeeeee 88; eeeee: 88–88%.
References
[117] | Meeee, M.; Meeeeee, M., Meee. Mee., (8888) 88, 888. |
[118] | Meeeeee, M. M.; Meeeeee, M. M.; Meee, M., Meeeeeeeeee Meee., (8888), 8888. |
[119] | Meeeeee, M. M.; Meeeeee, M. M., M. Mee. Meee., (8888) 88, 8888. |
[120] | Meeee, M. M.; Mee, M.; Meee, M.-M.; Meeeeeeee, M., M. Me. Meee. Mee., (8888) 888, 88888. |
[121] | Meeeee, M. M. M.; Meeee, M.; Meeeee, M. M., Meeeeeeee, (8888), 888. |
[122] | Meeeee, M., Meeee. Meee., (8888) 88, 888; Meeee. Meee. Mee. Me. Meee., (8888) 88, 888. |
[123] | Meeeeeee, M. M.; Me Meeeeeeeeee, M.; Meee, M.; Meeeeeeee, M.; Meeeee, M.; Meeeeeeeee, M.; Meeeeeee, M. M.; Meeeeeee, M., Meeeeeeeeee, (8888) 88, 8888. |
[124] | Meeeeeeee, M. M.; Meeeee, M.; Meeeeee, M. M., Meeeeeeeeee Meee., (8888) 88, 8888. |
[125] | Meeeeeeee, M. M.; Meeeeee, M. M.; Meeeee, M., M. Meee. Mee., Meeeee Meeee. 8, (8888), 8888. |
[126] | Meeeee, M., Meeeeeeeeee Meee., (8888), 888. |
[127] | Meeeeeee, M. M.; Meeeeeeeeeee, M. M.; Meeeeeee, M. M.; Meeee’eee, M. M., Me. Mee. Meee., (8888) 88, 888; M. Mee. Meee. MMMM (Meee. Meeeee.), (8888) 88, 888. |
[128] | Meeeeee, M. M.; Meeeeee, M. M.; Meeeeee, M. M., Meee. Meeeeeeeeee. Meeeee., (8888), 888; Meee. Meeeeeeeee. Meeee. (Meee. Meeeee.), (8888) 8, 888. |
[129] | Meeeeee, M. M.; Meeeee, M. M.; Meeeeee, M. M., Me. Mee. Meee., (8888) 8, 8888; M. Mee. Meee. MMMM (Meee. Meeeee.), (8888) 8, 8888. |
[130] | Meeeeee, M. M.; Meeeeee, M. M.; Meeeeee, M. M.; Meeeeeee, M. M., Me. Mee. Meee., (8888) 8, 8888; M. Mee. Meee. MMMM (Meee. Meeeee.), (8888) 8, 8888. |
[131] | Meeeeeee, M.; Meeee, M. M.; Meeeee, M.; Meeeeeeeee, M., M. Meee. Mee., Meeeee Meeee. 8, (8888), 8888. |
[132] | Meüeeeeeee, M., Meeee. Meee., (8888) 88, 888; Meeee. Meee. Mee. Me. Meee., (8888) 8, 888. |
[133] | Meeeeeee, M. M.; Me Meeeeeeeeee, M.; Meeeeeeee, M.; Meeeeeeeee, M.; Meeeee, M. M., Meeeeeeeeee, (8888) 88, 8888. |
[134] | Meeeeeeee, M. M.; Meee, M. M.; Me Meéeee, M., Me e-MMMM Meeeeeeeeeee ee Meeeeeee eee Meeeeee Meeeeeeee, Meeeeeee, M. M.; Meeee, M.; Meeee, M. M.; Meeeeeee, M., Mee.; Meeee: Mee Meee, (8888); MMM: 88.8888/888888888M.ee888.eee8; eeeeeeeee eeeeee ee eeee://eee.eee.eeeeeeeeeeee.eeeee.eee/eeee/eeeeeeee/ee888/eeeee.eeee. |