Correction: Cu(II)-Mediated aerobic oxidative synthesis of sulfonated chromeno[4,3-c]pyrazol-4(2H)-ones

Abstract

Correction for ‘Cu(II)-Mediated aerobic oxidative synthesis of sulfonated chromeno[4,3-c]pyrazol-4(2H)-ones’ by Quan Zhou et al., Org. Biomol. Chem., 2022, 20, 5575–5581, https://doi.org/10.1039/D2OB00639A.

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The authors regret that the molecules 3ia, 3ib in the original article (Scheme 2) were incorrectly reported. Instead, they are N-sulfonated quinolin-2(1H)-one-3-carboxamides, which was disclosed by X-ray diffraction and reported by the authors in a recent publication.¹

The corrections to the article are detailed below.

1. The correct Scheme 2 is shown here incorporating the corrected structures for 3ia, 3ib.

Scheme 2 Scope of salicylaldehyde propiolates. Reaction conditions: 1 (0.30 mmol), 2 (0.33 mmol), Cu(OAc)₂ (1.0 equiv.), 1,2-dichloroethane (6.0 mL), 60 °C, air, 6 h; isolated yield of the product; ^a 4 mmol scale, O₂ (1 atm), 12 h; ^b With TFA (1 eq.) as additive.

2. In the Experimental section the corrected details for 3ia and 3ib are:

2-Oxo-N-tosyl-1,2-dihydroquinoline-3-carboxamide (3ia). White solid (51 mg, 49%); mp: 298–301 °C; ¹H NMR (400 MHz, DMSO-d₆) δ 8.85 (s, 1H), 7.94 (d, J = 8.2 Hz, 3H), 7.76–7.65 (m, 1H), 7.45 (d, J = 8.2 Hz, 3H), 7.33 (t, J = 7.5 Hz, 1H), 2.39 (s, 3H); ¹³C NMR (101 MHz, DMSO-d₆) δ 167.3, 166.0, 151.5, 149.9, 145.1, 141.1, 139.4, 135.6, 134.9, 133.2, 128.7, 124.0, 123.9, 121.0, 26.3; HRMS (ESI) ([M + H]⁺) calcd for [C₁₇H₁₅N₂O₄S⁺]: 343.0747 (100.0%), found: 343.0745 (100%).

N-((3-Bromophenyl)sulfonyl)-2-oxo-1,2-dihydroquinoline-3-carboxamide (3ib). White solid (45 mg, 37%); mp: 265–270 °C; ¹H NMR (400 MHz, DMSO-d₆) δ 8.93 (s, 1H), 8.27–8.20 (m, 1H), 8.11–8.06 (m, 1H), 7.98 (m, 2H), 7.75 (t, J = 7.8 Hz, 1H), 7.63 (t, J = 8.0 Hz, 1H), 7.48 (t, J = 8.7 Hz, 1H), 7.35 (t, J = 7.6 Hz, 1H); ¹³C NMR (101 MHz, DMSO) δ 162.6, 161.6, 147.0, 141.1, 140.4, 137.4, 134.8, 132.0, 130.9, 130.8, 127.4, 124.0, 122.3, 119.1, 116.3; HRMS (ESI) ([M + H]⁺) calcd for [C₁₆H₁₂BrN₂O₄S]: 406.9696 (100%), 408.9675 (97.3%), found: 406.9696 (100%), 408.9663 (97.3%).

3. In the abstract: “… we developed a concise and facile synthesis of 2-sulfonylated chromeno [4,3-c]pyrazol-4(2H)-ones or 2,5-dihydro-4H-pyrazolo[4,3-c]quinolin-4-ones via Cu(II)-promoted oxidative …” should read “… we developed a concise and facile synthesis of 2-sulfonylated chromeno[4,3-c]pyrazol-4(2H)-ones via Cu(II)-promoted oxidative …”

4. The table of contents graphic should be corrected to:

5. The final sentence in the Introduction “Herein, a feasible protocol (Scheme 1f) was developed for sulfonylated pyrazole fused chromeno/quinolinone via corresponding propiolates and sulfonohydrazides” should read “Herein, a feasible protocol (Scheme 1f) was developed for sulfonylated pyrazole fused chromeno via corresponding propiolates and sulfonohydrazides”.

6. Conclusion: “Such strategy provides a quick avenue to develop a drug library of chromeno/quinolinone fused with pyrazole rings.” should read “Such a strategy provides a quick avenue to develop a drug library of chromeno fused with pyrazole rings.”

7. The corrected structures for compounds 3ia and 3ib have been included in the updated ESI.

The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.

References

1. X. Chen, S.-J. Fang, Q. Zhou, W. Huang, Q.-L. Liu and L. Wang, Org. Biomol. Chem., 2024 10.1039/D4OB01071J.

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