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Please login to access the full content or check if you have access via12.1.1.2.1.1.1.2 Variation 2: From 3,3-Dialkoxyalkan-1-ones and Hydrazines
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Stanovnik, B.; Svete, J., Science of Synthesis, (2002) 12, 24.
The reaction of 3,3-dialkoxybutan-1-ones with substituted hydrazines can potentially give a mixture of 1,3- and 1,5-disubstituted pyrazoles; however, in the absence of an acid only one pyrazole is formed. In this case, the corresponding hydrazone 6 of the carbonyl group is initially formed as an intermediate and this is followed by cyclization to the 1,3-disubstituted pyrazole derivative 7 (Scheme 8).[78]
Meeeee 8 8,8-Meeeeeee-8M-eeeeeeee eeee 8,8-Meeeeeeeeeeeee-8-eee eee Meeeeeeeeeeeeee[88]
8,8-Meeeeeeeeeeeee-8-eeee eee eeeeeeeee eeeeeee eeeee ee eeeeeee eeeeeeee ee 88°M ee eeeeee 8-eeeeeeeeeeeeee 8 (Meeeee 8).[88]
Meeeee 8 8-Meeeeeeeeeeeee eeee 8,8-Meeeeeeeeeeeee-8-eeee eee Meeeeeeeee[88]
Meeeeeeeeeee Meeeeeeee
8,8-Meeeeeee-8M-eeeeeeee (8):[88]
MeMMMM8 (8 e, 88.8 eeee) eee eeeee, eeeeeeee, eeee eeeeeee, ee 8,8-eeeeeeeeeeeeee-8-eee (8.8 e, 88.8 eeee). Mee eeeeeee eee eeeeeee ee eeee ee 88°M, eee eee eeeeee ee eee eeeee eeee eee 88 eee ee eeeeeeee eee eeeeeeeee ee eee 8,8-eeeeeeeeeeeeee-8-eee eeeeeeeeeeeeeee (8). 8 M MMe (8.8 e) eee eeeee ee e eeeeeee ee 8,8-eeeeeeeeeeeeee-8-eee eeeeeeeeeeeeeee (8.8 e, 88.8 eeee) eee M8M (8 eM), eee eee eeeeeeeee eeee eee eeeeee ee eee eeeee eeee eee 88 eee, eeeeee, eee eeeeeeeeeee eeee 88% ee MeMM (8.8 e). Mee eeeeeee eee eeeeeeeee eeee eeeeeee eeeeeeee ee Me8M, eeeee, eee eeeeeeeee; eeeee: 88%; ee 888–888°M.
8-Meeeeeeeeeeeee 8; Meeeeee Meeeeeeee:[88]
M eeeeeee ee 8,8-eeeeeeeeeeeeee-8-eee (88 eeee), M8MMM8•M8MM8 (8.88 e, 88 eeee), eee M8M (8 eM) eee eeeeee ee 88°M eee 8 e. Mee eeeeeee eee eeeeee, eeeeeeeeeee eeee M8MM8 ee eM 8, eee eee eeeeeeeeeee eee eeeeeeeee ee eeeeeeeeee ee eeee 8; eeeee: 88–88%.
References
[78] | Meeeeee, M. M., M. Mee. Meee., (8888) 88, 88. |
[79] | Meeeeeee, M. M.; Meeeeeee, M. M.; Meeeeeee, M. M., Me. Mee. Meee., (8888) 88, 8888; Meee. Meeee., (8888) 88, 888888e. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) M 88e8, 888.
- 8.Meeeee-Meee, (8888) M 8e, 888.