Metal-Free Synthesis of C-3-Alkoxycarbonylated 2H-Indazoles Using Alkyl Carbazates

Dipti Lai; Suvam Bhattacharjee; Sumit Ghosh; Subrata Sinha; Alakananda Hajra

doi:10.1055/a-2316-5066

Synlett, Table of Contents

Synlett 2024; 35(20): 2477-2481
DOI: 10.1055/a-2316-5066

letter

Special Issue to Celebrate the 75th Birthday of Prof. B. C. Ranu

Metal-Free Synthesis of C-3-Alkoxycarbonylated 2H-Indazoles Using Alkyl Carbazates

Authors

Dipti Lai

^aDepartment of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, West Bengal, India

^bIntegrated Science Education & Research Centre, Visva-Bharati (A Central University), Santiniketan 731235, West Bengal, India
Suvam Bhattacharjee

^aDepartment of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, West Bengal, India
Sumit Ghosh

^aDepartment of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, West Bengal, India

^bIntegrated Science Education & Research Centre, Visva-Bharati (A Central University), Santiniketan 731235, West Bengal, India
Subrata Sinha

^bIntegrated Science Education & Research Centre, Visva-Bharati (A Central University), Santiniketan 731235, West Bengal, India
Alakananda Hajra∗

^aDepartment of Chemistry, Visva-Bharati (A Central University), Santiniketan, 731235, West Bengal, India

Abstract

All articles of this category

This paper is dedicated to Professor Brindaban C. Ranu on the occasion of his 75^th birthday.

Abstract

A simple, efficient, and environmentally benign method for the direct C-3-alkoxycarbonylation of 2H-indazoles using alkyl carbazates has been developed under metal-free conditions at room temperature. This current protocol represents a facile access to C-3-carboxylic ester derived 2H-indazoles with wide functional group tolerance in good to excellent yields. The mechanistic studies suggest that the reaction proceeds through a radical pathway.

Key words

metal-free - C-3-alkoxycarbonylation - 2H-indazole - synthetic transformations - alkyl carbazate

Full Text

References

References and Notes

1a Zhao Y, Li Y, Ou X, Zhang P, Huang Z, Bi F, Huang R, Wang Q. J. Agric. Food Chem. 2008; 56: 10176
1b Szűts A, Szabó-Révész P. Int. J. Pharm. 2012; 433: 1
1c Ortega-Requena S, Montiel C, Máximo F, Gómez M, Murcia MD, Bastida J. Materials 2024; 17: 268

2a Levin JI, Turos E, Weinreb SM. Synth. Commun. 1982; 12: 989
2b Zhang J, Leitus G, Ben-David Y, Milstein D. Angew. Chem. Int. Ed. 2006; 45: 1113
2c Shi Y, Liu X, Cao H, Bie F, Han Y, Yan P, Szostak R, Szostak M, Liu C. Org. Biomol. Chem. 2021; 19: 2991

3 Pimparkar S, Dalvi AK, Koodan A, Maiti S, Al-Thabaiti SA, Mokhtar M, Dutta A, Lee YR, Maiti D. Green Chem. 2021; 23: 9283
4 Schoenberg A, Bartoletti I, Heck RF. J. Org. Chem. 1974; 39: 3318

5a Munday RH, Martinelli JR, Buchwald SL. J. Am. Chem. Soc. 2008; 130: 2754
5b Brennfuhrer A, Neumann H, Beller M. Angew. Chem. Int. Ed. 2009; 48: 4114
5c Ueda T, Konishi H, Manabe K. Org. Lett. 2012; 14: 3100

6a Godard C, Muñoz BK, Ruiz A, Claver C. Dalton Trans. 2008; 853
6b Brennführer A, Neumann H, Beller M. ChemCatChem 2009; 1: 28
6c Liu Q, Zhang H, Lei A. Angew. Chem. Int. Ed. 2011; 50: 10788
6d Kalck P, Urrutigoïty M. Inorg. Chim. Acta 2015; 431: 110

7a Taniguchi T, Sugiura Y, Zaimoku H, Ishibashi H. Angew. Chem. Int. Ed. 2010; 49: 10154
7b Su YH, Wu Z, Tian SK. Chem. Commun. 2013; 49: 6528
7c Ding R, Zhang QC, Xu YH, Loh TP. Chem. Commun. 2014; 50: 11661
7d Wang G, Wang S, Wang J, Chen SY, Yu XQ. Tetrahedron 2014; 70: 3466

8a Gao Y, Lu W, Liu P, Sun P. J. Org. Chem. 2016; 81: 2482
8b Li C.-K, Zhang D.-L, Olamiji OO, Zhang P.-Z, Shoberu A, Zou J.-P, Zhang W. Synthesis 2018; 50: 2968
8c Li X, Fang M, Hu P, Hong G, Tang Y, Xu X. Adv. Synth. Catal. 2014; 356: 2103
8d Xie L.-Y, Peng S, Fan T.-G, Liu Y.-F, Sun M, Jiang L.-L, Wang X.-X, Cao Z, He W. Sci. China: Chem. 2019; 62: 460
8e Sarothiya D, Bhawale RT, Kshirsagar UA. J. Org. Chem. 2022; 87: 14915

9a Lee F.-Y, Lien J.-C, Huang L.-J, Huang T.-M, Tsai S.-C, Teng C.-M, Wu C.-C, Cheng F.-C, Kuo S.-C. J. Med. Chem. 2001; 44: 3746
9b Haddadin MJ, Conrad WE, Kurth MJ. Mini-Rev. Med. Chem. 2012; 12: 1293
9c Zhang S.-G, Liang C.-G, Zhang W.-H. Molecules 2018; 23: 2783
9d Rodríguez-Villar K, Yépez-Mulia L, Cortés-Gines M, Aguilera-Perdomo JD, Quintana-Salazar EA, Olascoaga Del Angel KS, Cortés-Benítez F, Palacios-Espinosa JF, Soria-Arteche O, Pérez-Villanueva J. Molecules 2021; 26: 2145

10a Jia Y, Zhang J, Feng J, Xu F, Pan H, Xu W. Chem. Biol. Drug Des. 2014; 83: 306
10b Cerecetto H, Gerpe A, González M, Arán VJ, De Ocáriz CO. Mini-Rev. Med. Chem. 2005; 5: 869

11a Murugan A, Gorantla KR, Mallik BS, Sharada DS. Org. Biomol. Chem. 2018; 16: 5113
11b Mahanty K, Maiti D, De Sarkar S. J. Org. Chem. 2020; 85: 3699
11c Liu L, Jiang P, Liu Y, Du H, Tan J. Org. Chem. Front. 2020; 7: 2278
11d Kim W, Kim HY, Oh K. Org. Lett. 2020; 22: 6319
11e Sun M, Li L, Wang L, Huo J, Sun M, Li P. Org. Chem. Front. 2021; 8: 4230
11f Laru S, Bhattacharjee S, Hajra A. Chem. Commun. 2022; 58: 13604
11g Ma C.-H, Zhao L, He X, Jiang Y.-Q, Yu B. Org. Chem. Front. 2022; 9: 1445
11h Yang Z, Yu J.-T, Pan C. Org. Biomol. Chem. 2022; 20: 7746

12a Neogi S, Ghosh AK, Majhi K, Samanta S, Kibriya G, Hajra A. Org. Lett. 2020; 22: 5605
12b Bhattacharjee S, Laru S, Ghosh P, Hajra A. J. Org. Chem. 2021; 86: 10866
12c Ghosh P, Hajra A. J. Org. Chem. 2021; 86: 10883
12d Das KK, Hajra A. Org. Biomol. Chem. 2024; 22: 1034

13a Theodorou V, Skobridis K, Tzakosb AG, Ragoussis V. Tetrahedron Lett. 2007; 48: 8230
13b Bhattacharjee S, Hajra A. Org. Lett. 2023; 25: 4183

14a Guo S, Lu L, Cai H. Synlett 2013; 24: 1712
14b Xu X, Tang Y, Li X, Hong G, Fang M, Du X. J. Org. Chem. 2014; 79: 446
14c Pan C, Han J, Zhang H, Zhu C. J. Org. Chem. 2014; 79: 5374
14d Zong Z, Lu S, Wang W, Li Z. Tetrahedron Lett. 2015; 56: 6719
14e Wang S.-N, Zhang G.-Y, Shoberu A, Zou J.-P. J. Org. Chem. 2021; 86: 9067

15 General Experimental Procedure for the Synthesis of C-3-Alkoxycarbonylated 2H-Indazoles 3 and 5 A mixture of 2-arylindazoles 1/4 (0.2 mmol), alkyl hydrazinecarboxylate 2 (2.0 equiv), and TBHP (4.0 equiv, 0.14 mL) was taken in an oven-dried reaction tube under N₂ atmosphere. Then 1,2-DCE (2 mL) was added to it using a syringe, and the reaction mixture was further stirred at room temperature for 8 h under N₂ atmosphere. After completion of the reaction (TLC), the reaction mixture was extracted with DCM (10 mL). The organic phase was dried over anhydrous Na₂SO₄ and concentrated under reduced pressure to get the crude residue which was purified by column chromatography on silica gel (100–200 mesh) using a mixture of petroleum ether and ethyl acetate as an eluent to afford the corresponding products 3/5. Analytical Data for Compound 3ha White solid (67%, 42.9 mg); R_f = 0.50 (PE:EtOAc = 96:4); mp 155–156 °C. ¹H NMR (400 MHz, CDCl₃): δ = 8.10 (d, J = 8.4 Hz, 1 H), 7.85 (d, J = 8.4 Hz, 1 H), 7.80 (d, J = 8.4 Hz, 2 H), 7.68 (d, J = 8.0 Hz, 2 H), 7.46–7.42 (m, 1 H), 7.39–7.35 (m, 1 H), 3.94 (s, 3 H). ¹³C{¹H} NMR (100 MHz, CDCl₃): δ = 160.0, 148.9, 143.6, 131.6, 131.3, 127.7, 127.0, 126.2, 125.9 (q, J _C–F = 4.0 Hz), 124.2, 123.8 (q, J _C–F = 271.0 Hz), 121.6, 118.8, 52.3. FTIR: ν = 3055, 1708, 1616, 1462, 1296, 1103 cm^–1. HRMS (ESI-TOF): m/z [M + H]⁺ calcd for [C₁₆H₁₂F₃N₂O₂]⁺: 321.0845; found: 321.0841. Analytical Data for Compound 5aa White solid (77%, 45.6 mg); R_f = 0.5 (PE:EtOAc = 94 : 6); mp 134–135 °C. ¹H NMR (400 MHz, CDCl₃): δ = 7.72 (d, J = 9.2 Hz, 1 H), 7.39–7.37 (m, 2 H), 7.31–7.29 (m, 3 H), 7.10–7.07 (m, 1 H), 3.92 (s, 3 H), 3.89 (s, 3 H), 2.45 (s, 3 H). ¹³C{¹H} NMR (100 MHz, CDCl₃): δ = 160.3, 158.1, 145.2, 139.3, 138.7, 129.3, 126.0, 125.0, 123.9, 122.0, 120.1, 97.9, 55.6, 51.9, 21.4. FTIR: ν = 3032, 1712, 1631, 1442, 1211, 1126 cm^–1. HRMS (ESI-TOF): m/z [M + H]⁺ calcd for [C₁₇H₁₇N₂O₃]⁺: 297.1234; found: 297.1225.

Supplementary Material

Supporting Information (PDF) (opens in new window)