Efficient Method to Synthesize Benzhydrazides by In Situ 
Oxidation/Coupling of Benzylic Alcohols with Azodicarboxylates

Kobra Azizi; Akbar Heydari

doi:10.1055/s-0036-1591311

Synlett, Table of Contents

Synlett 2018; 29(02): 189-192
DOI: 10.1055/s-0036-1591311

letter

Efficient Method to Synthesize Benzhydrazides by In Situ Oxidation/Coupling of Benzylic Alcohols with Azodicarboxylates

Kobra Azizi

Chemistry Department, Tarbiat Modares University, P. O. Box 14155-4838 Tehran, Iran Email: heydar_a@modares.ac.ir

,

Akbar Heydari*

Chemistry Department, Tarbiat Modares University, P. O. Box 14155-4838 Tehran, Iran Email: heydar_a@modares.ac.ir

› Author Affiliations

Abstract

All articles of this category

Abstract

An efficient synthesis of benzhydrazides has been achieved through the direct acylation of azodicarboxylates with benzylic alcohols in moderate to high yields. The method represents the first practical approach to amides containing a hydrazine structural unit from benzylic alcohols.

Key words:

benzhydrazides - hydroacylation - azodicarboxylates - C–N bond formation

Full Text

References

References and Notes
1 Inamdar SM. More VK. Mandal SK. Chem. Lett. 2012; 41: 1484
2 Nair V. Menon RS. Sreekanth AR. Abhilash N. Biju AT. Acc. Chem. Res. 2006; 39: 520
3 Kharasch MS. Zimmermann M. Zimmt W. Nudenberg W. J. Org. Chem. 1953; 18: 1045
4 Chatgilialoglu C. Crich D. Komatsu M. Ryu I. Chem. Rev. 1999; 99: 1991
5 Mariappan A. Rajaguru K. Muthusubramanian S. Bhuvanesh N. Tetrahedron Lett. 2015; 56: 338

6a Zaballos-García E. González-Rosende ME. Jorda-Gregori JM. Sepúlveda-Arques J. Jennings WB. O’Leary D. Twomey S. Tetrahedron 1997; 53: 9313
6b Chudasama V. Ahern JM. Dhokia DV. Fitzmaurice RJ. Caddick S. Chem. Commun. 2011; 47: 3269

7 Kim YJ. Lee D. Org. Lett. 2004; 6: 4351

8a Zhang Q. Parker E. Headley AD. Ni B. Synlett 2010; 2453
8b Ni B. Zhang Q. Garre S. Headley AD. Adv. Synth. Catal. 2009; 351: 875

9 Qin Y. Peng Q. Song J. Zhou D. Tetrahedron Lett 2011; 52: 5880

10a Sasano Y. Nagasawa S. Yamazaki M. Shibuya M. Park J. Iwabuchi Y. Angew. Chem. Int. Ed. 2014; 53: 3236
10b Rogan L. Hughes NL. Cao Q. Dornan LM. Muldoon MJ. Catal. Sci. Technol. 2014; 4: 1720

11 Markó IE. Giles PR. Tsukazaki M. Brown SM. Urch CJ. Science 1996; 274: 2044
12 McCann SD. Stahl SS. J. Am. Chem. Soc. 2016; 138: 199
13 Pérez JM. Ramón DJ. Adv. Synth. Catal. 2014; 356: 3039
14 Lee D. Otte RD. J. Org. Chem. 2004; 69: 3569
15 Dialkyl 1-Aroylhydrazine-1,2-dicarboxylates; General Procedure
The appropriate dialkyl azodicarboxylate (1.5 mmol) was added to a stirred mixture of CuO nanoparticles (10 mol%) and a benzylic alcohol (0.75 mmol) in MeCN (0.5 mL) under argon. A 30% solution of t-BuOOH (2 equiv) was added dropwise, and the mixture was stirred at 80 °C for 6 h. When the benzaldehyde generated in situ had been consumed (TLC; decolorization of the azodicarboxylate was also observed), the mixture was treated with NaBH₄ (0.5 mmol, 20 mg) in MeOH (0.5 mL). After 5 min, the reaction was quenched with aq NH₄Cl (1 mL) and brine (1 mL). The cooled mixture was centrifuged to separate the catalyst then extracted with EtOAc (2 × 20 mL). The extracts were dried (MgSO₄), filtered, and concentrated in vacuo to give a crude product that was purified by column chromatography [silica gel, EtOAc–hexanes (1:4)]. Diisopropyl 1-Benzoylhydrazine-1,2-dicarboxylate White solid; yield: 85%; mp 123 °C. ¹H NMR (500 MHz, CDCl₃): δ = 7.7 (m, 2 H), 7.52 (t, J = 7.4 Hz, 1 H), 7.4–7.45 (m, 2 H), 7.26 (br s, 1 H), 4.98–5.05 (m, 1 H), 4.8–4.9 (m, 1 H), 1.29 (d, J = 6.0 Hz, 6 H), 1.08 (d, J = 5.4 Hz, 6 H). Diethyl 1-Benzoylhydrazine-1,2-dicarboxylate Colorless oil; yield: 80%. ¹H NMR (500 MHz, CDCl₃): δ = 7.68 (d, J = 7.2 Hz, 2 H), 7.30–7.50 (m, 3 H), 7.24 (br s, 1 H), 4.23 (q, J = 7.2 Hz, 2 H), 4.15 (q, J = 7.2 Hz, 2 H), 1.29 (t, J = 7.2 Hz, 3 H), 1.07 (t, J = 7.2 Hz, 3 H).