Electronic Supplementary Information

Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry. This journal is The Royal Society of Chemistry 205 Electronic Supplementary Information DMSO/I 2 mediated C C bond cleavage of α-ketoaldehydes followed by C O bond formation: A metal-free approach for one-pot esterification Vunnam Venkateswarlu, a,c K. A. Aravinda Kumar, a Sorav Gupta, a,c Deepika Singh, b,c Ram A. Vishwakarma, a,c Sanghapal D. Sawant a,c a Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu-80 00, India b QC-QA Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu-80 00, India c Academy of Scientific and Innovative Research, Anusandhan Bhawan, 2 Rafi Marg, New Delhi-0 00, India. E-mail: sdsawant@iiim.res.in, sawant.rrl@gmail.com Tel: +9-92585222; Fax: +9-92586333 IIIM communication No.: IIIM/78/205

MS mass peaks of intermediates and product.0. Example for formation of carboxylic acid product : Figure showing ESI-MS and GC- Fig. S [A] The ESI-MS analysis of reaction mixture for (b), collected during progress of reaction at an interval of four hour showing the mass peaks of intermediates predicted as per plausible mechanism; [B] reaction mixture after 6 hr, shows completion of reaction; [C] GC- MS of crude sample of b, showing (MS peak A) for product 2b, and (MS peak 2A) for the fragment formed during the reaction. [D] and [E] The fragmentation pattern obtained for product and/or intermediate in GC-MS analysis 2

2.0. Analytical data: Benzoic acid (2a) a,b : (400 MHz, MeOD): δ 8.03 (d, J = 7.6 Hz, 2H), 7.54 (t, J = 7.3 Hz, H), 7.43 (t, J = 7.6 Hz, 2H). 3 (0 MHz, MeOD): δ 70., 34., 3.8, 30.8, 29.50. (+) ESI-MS: 45. (M + + Na). 2-Bromobenzoic acid (2b) a : (400 MHz, MeOD) δ 7.70-7.67 (m, H), 7.58 (d, J = 8.0 Hz, H), 7.33-7.25 (m, 2H). 3 (26 MHz, MeOD) δ 69.6, 35.3, 34.5, 33.6, 32., 28.4, 22.0. (-) ESI-MS: 99.2 (M + -). 4-Bromobenzoic acid (2c) a,b,d : (400 MHz, MeOD) δ 7.82 (d, J = 8.5 Hz, 2H), 7.55 (d, J = 8.5 Hz, 2H). 3 (26 MHz, MeOD) δ 68.8, 32.8, 32.5, 3., 28.8; (-) ESI-MS: 99.2 (M + -). 3-Nitrobenzoic acid (2d) a : (400 MHz, MeOD) δ 8.65 (d, J =.7 Hz, H), 8.36 8.3 (m, H), 8.26 (d, J = 7.7 Hz, H), 7.63 (t, J = 8.0 Hz, H). 3 (26 MHz, MeOD) δ 65.9, 48.2, 35.0, 32.4, 29.6, 26.8, 23.8. (-) ESI-MS: 66. (M + -). 3-bromo-4-fluorobenzoic acid (2e) e : (400 MHz, CDCl 3 ): δ 8.34 (m, H), 8.07 (m, H), 7.23 (m, H). 9 F NMR (376 MHz, CDCl 3 ) δ -98. (td, J = 7.2, 5.2 Hz). 3 (0 MHz, CDCl3): δ 70.2, 62.7 (d, J = 256.2 Hz), 36. (d, J =.7 Hz), 3.5 (d, J = 8.8 Hz), 26.7 (d, J = 3.5 Hz), 6.7 (d, J = 23. Hz), 09.5 (d, J = 2.8 Hz); (-) ESI-MS: 26.8 (M + -). 2,4-dichlorobenzoic acid (2f) b : (400 MHz, CDCl 3 ) δ 7.99 (d, J = 8.5 Hz, H), 7.53 (d, J =.9 Hz, H), 7.35 (dd, J = 8.5, 2.0 Hz, H). 3 (0 MHz, CDCl 3 ) δ 69.2, 39.5, 36.0, 33.5, 3.4, 27.. (-) ESI-MS: 89.2 (M + -). 4-Chlorobenzoic acid (2g) b,d : (400 MHz, MeOD) δ 7.89 (d, J = 8.6 Hz, 2H), 7.38 (d, J = 8.6 Hz, 2H). 3 (0 MHz, MeOD) δ 68.7, 40.2, 32.3, 29.7. (-) ESI-MS: 55.2 (M + -) 3-Bromo-4-methoxybenzoic acid (2h) c : (400 MHz, MeOD) δ 8.05 (d, J = 2. Hz, H), 7.90 (dd, J = 8.6, 2. Hz, H), 7.0 (d, J = 8.7 Hz, H), 3.85 (s, 3H). 3 (26 MHz, MeOD): δ 68.4, 6.0, 35.7, 32.0, 25.4, 2.5, 2., 57.0; (-) ESI-MS: 228.9 (M + -). 3,4-Dimethylbenzoic acid (2i) d : (400 MHz, CDCl 3 ) δ 7.93 7.8 (m, 2H), 7.28 7.8 (m, H), 2.33 (d, J = 4.5 Hz, 6H). 3 (0 MHz, CDCl 3 ) δ 72.7, 43.3, 36.8, 3.2, 29.8, 27.8, 26.9, 20., 9.67; (-) ESI-MS: 48.8 (M + -). 3

4-Fluorobenzoic acid (2j) d : (400 MHz, CDCl 3 ) δ 8.6 8.3 (m, 2H), 7.5 (t, J = 8.0 Hz, 2H). 3 (25 MHz, CDCl 3 ) δ 68.7, 68.4, 65.9, 38.5, 33.4, 28.4, 6.5; (-) ESI- MS: 39.0 (M + -). 4-Nitirobenzoic acid (2k) a,b : (400 MHz, MeOD) δ 8.23 (d, J = 8.8 Hz, 2H), 8.3 (d, J = 8.8 Hz, 2H). 3 (26 MHz, MeOD) δ 67.6, 5.9, 37.6, 3.9, 24.5. (-) ESI-MS: 66.2 (M + -). 4-Methylbenzoic acid (2l) a,b : (400 MHz, CDCl 3 ) δ 8.03 (d, J = 8. Hz, 2H), 7.27 (t, J = 8. Hz, 2H), 2.46 (s, 3H). 3 (0 MHz, MeOD) δ 70.0, 45.0, 30.8, 30., 29., 2.6; (+) ESI-MS: 37.4 (M + + ). 4-Phenylbenzoic acid (2m) d : (500 MHz, MeOD) δ 7.99 (dt, J = 8.4,.8 Hz, 2H), 7.65 7.60 (m, 2H), 7.59 7.55 (m, 2H), 7.38 7.35 (m, 2H), 7.3 7.26 (m, H). 3 (26 MHz, MeOD) δ 69.7, 47.0, 4.2, 3.3, 30.6, 30.0, 29.2, 28.2, 28.0. (-) ESI-MS: 97.3 (M + -). 3,4,5-Trimethoxybenzoic acid (2n) e : (400 MHz, CDCl 3 ) δ 7.38 (s, 2H), 3.94 (s, 3H), 3.93 (s, 6H). 3 (26 MHz, CDCl 3 ) δ 7.4, 52.9, 42.9, 24., 07.3, 60.9, 56.2. (-) ESI-MS: 2.2 (M + -). 4-methoxybenzoic acid (2o) a,b : (500 MHz, MeOD) δ 7.87 (d, J = 8.9 Hz, 2H), 6.87 (d, J = 8.9 Hz, 2H), 3.75 (s, 3H). 3 (26 MHz, MeOD): δ69.8, 65.0, 32.8, 24.0, 4.6, 55.9. (-) ESI-MS: 5.2(M + -) 4-methoxy-2-methylbenzoic acid (2p) c : (400 MHz, DMSO-d 6 ) δ 7.84 (d, J=8.3Hz, H), 6.84 (s,h), 6.82 (s, H), 3.79 (s, 3H), 2.52 (s, 3H). 3 CMR (26MHz, DMSO-d 6 ) δ 68.0, 6.7, 42., 32.7, 22.0, 6.6,., 55.2, 2.8, (+) ESI-MS: 63.3 (M + +). 4-(tert-butyl)benzoic acid a (2q): (400 MHz, CDCl 3 ): δ 8.04 (d, J = 8.5 Hz, 2H), 7.49 (d, J = 8.5 Hz, 2H),.35 (s, 9H). 3 (26 MHz, CDCl 3 ): δ 72.4, 50.2, 30., 29., 25.6, 40.6, 3.3. (-) ESI-MS: 77.2 (M + -). 4-bromo-3-chlorobenzoic acid l (2r): (400 MHz, CDCl 3 ): δ 7.99-7.96 (t, H), 7.65-7.62 (m, H), 7.42-7.4 (d, J = 4 Hz, H). 3 (26 MHz, CDCl 3 ): δ 67.4, 36.5, 34.9, 34.0, 33.7, 33.5, 2.. (-) ESI-MS: 232.9 (M + -). 3-chlorobenzoicacid b (2s): (400 MHz, CDCl 3 ): δ 8.09 (s, H), 8.00 (d, J = 7.7 Hz, H), 7.59 (d, J = 8.0 Hz, H), 7.42 (t, J = 7.9 Hz, H). 3 (0 MHz, MeOD): δ 68.4, 35.5, 33.9, 3.2, 30.5, 29.0. 4

Nicotinic acid g (3a) : (400 MHz, MeOD) δ 9.02 (s, H), 8.64 (d, J = 3.6 Hz, H), 8.32 (dt, J = 7.9,.8 Hz, H), 7.48 (dd, J = 7.7, 5. Hz, H); 3 (0 MHz, MeOD) δ 67.7, 53.6, 5.2, 39.3, 28.7, 25.3. (+) ESI-MS: 24.2 (M + +). 5-methylthiophene-2-carboxylic acid h (3b): (500 MHz, CDCl 3 ) δ 7.7 (d, J = 2.6 Hz, H), 6.8 (s, H), 2.55 (s, 3H). 3 (26 MHz, CDCl 3 ) δ 65.6, 47.7, 33.4, 28.0, 24.6, 3.7. (+) ESI-MS: 43. (M + +). 4-Phenoxybenzoic acid c (3c): (400 MHz, CDCl3): δ 8.08 (d, J = 8.8 Hz, 2H),.4 (t, J = 7.9 Hz, 2H), 7.2 (t, J = 7.4 Hz, H), 7.09 (d, J = 7.7 Hz, 2H), 7.0 (d, J = 8.8 Hz, 2H). 3 C NMR (26 MHz, MeOD): δ 69.3, 63.4, 57.09, 33.0, 3.2, 26., 25.7, 2.2, 8.2. Benzofuran-2carboxylic acid c (3d): (500 MHz, MeOD): δ 7.72 (d, J = 7.9 Hz, H), 7.57 (t, J = 4.2 Hz, 2H), 7.48 7.44 (m, H), 7.3 (t, J = 7.5 Hz, H). 3 (26 MHz, MeOD): δ 6.0, 55.7, 46.0, 27.3, 27., 23.5, 22.6, 3.4,.5. ESI-MS: 63.2 (M + +H). 2-Furaic acid j (3e): (500 MHz, CDCl 3 ): δ 0.92 (s, H), 7.65 (d, J = 2. Hz, H), 7.34 (dd, J = 22.5, 3.4 Hz, H), 6.59 6.54 (m, H). 3 (26 MHz, CDCl 3 ): δ 63.8, 47.5, 43.8, 20.2, 2.3. (+) ESI-MS: 3.2 (M + +). Methyl benzoate 2a (4a): (400 MHz, CDCl 3 ) δ 8.09 7.99 (m, 2H), 7.67 (t, J = 7.4 Hz, H), 7.52 (t, J = 7.8 Hz, 2H), 3.99 (s, 3H); GC-MS:36. (M + ). Methyl 4-methoxybenzoate 2a (4b): (400 MHz, CDCl 3 + CD 3 OD) δ 8.00 (d, J = 8.7 Hz, 2H), 6.92 (d, J = 8.8 Hz, 2H), 3.89 (s, 3H), 3.86 (s, 3H). Methyl 2-fluorobenzoate 2b (4c): (400 MHz, CDCl 3 ) δ 7.94 (td, J = 7.6,.8 Hz, H), 7.55 7.46 (m, H), 7.24 7.07 (m, 2H), 3.93 (s, 3H); GC-MS:54.0 (M + ). Methyl 4-aminobenzoate 2a (4d): (400 MHz, CDCl 3 ) δ 7.84 (d, J = 8.6 Hz, 2H), 6.62 (d, J = 8.6 Hz, 2H), 4.5 (s, 2H), 3.84 (s, 3H); GC-MS:5. (M + ). 3 (26 MHz, CDCl 3 ): δ 67.28, 5.02, 3.6, 9.52, 3.79, 5.64. Methyl 5-methylthiophene-2-carboxylate 2c (4e): (400 MHz, CDCl 3 ) δ 7.6 (d, J = 3.7 Hz, H), 6.76 (dd, J = 3.7, 0.9 Hz, H), 3.86 (s, 3H), 2.52 (s, 3H). Ethyl benzofuran-2-carboxylate 2d (4f): (400 MHz, CDCl 3 ) δ 7.67 (d, J = 7.9 Hz, H), 7.59 (d, J = 8.4 Hz, H), 7.52 (s, H), 7.46 7.39 (m, H), 7.29 (dd, J = 3.2, 6.0 Hz, H), 4.44 (q, J = 7. Hz, 2H),.42 (t, J = 7. Hz, 3H). 5

Dihydro β-ionic Acid 2e (5a): (400 MHz, CDCl 3 ): δ 2.43 2.39 (m, 2H), 2.37 2.34 (m, 2H),.93-.89 (t, J = 6.2 Hz, 2H),.6 (s, 3H),.6.55 (m, 2H),.44.4 (m, 2H),.00 (s, 6H). 3 (0 MHz, CDCl 3 ): δ 80.3, 35.4, 28.5, 39.7, 34.9, 34.7, 32.7, 28.3, 23.5, 9.65, 9.4. HRMS (+ESI, m/z) calc for C 2 H 20 O 2 (M + ) 96.458, found (M+H + ) 97.530 6

2.0. Scanned Spectra Benzoic Acid (2a): 3 7

2-Bromobenzoic acid (2b): 3 8

4-Bromobenzoic acid (2c): 3 9

3-Nitrobenzoic acid (2d): 3 0

3-bromo,4-Fluorobenzoic acid (2e): 9 F NMR

3 2

2,4-dichloro benzoic acid (2f): 3 3

4-Chloro benzoic acid (2g): 3 4

3-Bromo,4-methoxy benzoic acid (2h): 3 5

3,4-Dimethylbenzoic acid (2i): O OH 3 O OH 6

4-Fluorobenzoic acid (2j): 3 7

4-Nitiro benzoic acid (2k): 3 8

4-Methyl benzoic acid (2l): 3 9

4-Phenyl Benzoic acid (2m): 3 20

3,4,5 Trimethoxybenzoic acid (2n): 3 2

4-methoxybenzoic acid (2o): 3 22

4-methoxy-2-methylbenzoic acid (2p): 3 23

4-(tert-butyl)benzoic acid (2q): 2.00 2.00 9.02 2.00 2.00 8.05 8.03 7.50 7.48 8.05 8.03 7.50 7.48.35 8. 8.0 7.9 7.8 7.7 f (ppm) 7.6 7.5 7.4 8.0 7.5 3 7.0 6.5 6.0 5.5 5.0 4.5 4.0 f (ppm) 3.5 3.0 2.5 2.0.5.0 0.5 0.0 24

25 4-bromo-3-chlorobenzoic acid (2r): HNMR: 0.0 0.5.0.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 f (ppm).0.00.4 7.4 7.42 7.62 7.63 7.64 7.65 7.96 7.97 7.99 7.4 7.5 7.6 7.7 7.8 7.9 8.0 f (ppm).0.00.4 7.4 7.42 7.62 7.63 7.64 7.65 7.96 7.97 7.99 3 : 35 40 45 50 55 60 65 70 75 80 85 90 95 00 05 0 5 20 25 30 35 40 45 50 55 60 65 70 f (ppm) 2.9 33.50 33.73 34.07 34.97 36.50 67.40

3-Chlorobenzoic acid (2s):.00.00.0.0.00.00.0.0 8.09 8.0 7.99 7.60 7.58 7.44 7.42 7.40 8.09 8.0 7.99 7.60 7.58 7.44 7.42 7.40 8. 7.9 7.7 f (ppm) 7.5 7.3 8.0 3 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 f (ppm) 3.5 3.0 2.5 2.0.5.0 0.5 0.0 68.35 35.52 33.90 3.6 30.57 29.05 70 60 50 40 30 20 0 00 90 80 f (ppm) 70 60 50 40 30 20 0 0 26

Nicotinic acid (3a): 3 27

5-methylthiophene-2-carboxylic acid (3b):.02.00 3.02 7.72 7.7 6.8 2.55 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 f (ppm) 3.5 3.0 2.5 2.0.5.0 0.5 0.0 3 65.6 47.76 33.4 28.0 24.63 3.78 60 50 40 30 20 0 00 90 f (ppm) 80 70 60 50 40 30 20 0 28

4-Phenoxybenzoic acid (3c): 3 29

30 Benzofuran-2-carboxylic acid (3d): 0.0 0.5.0.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 f (ppm).03.06 2.00.03 7.29 7.3 7.32 7.44 7.45 7.46 7.48 7.48 7.56 7.57 7.58 7.7 7.73 7.3 7.4 7.5 7.6 7.7 f (ppm).03.06 2.00.03 7.29 7.3 7.32 7.44 7.45 7.46 7.48 7.48 7.56 7.57 7.58 7.7 7.73 3 40 45 50 55 60 65 70 75 80 85 90 95 00 05 0 5 20 25 30 35 40 45 50 55 60 f (ppm).56 3.45 22.64 23.50 27.0 27.33 46.02 55.74 6.09

2-Furaic acid (3e):.00.00.03.02 0.92 7.67 7.63 7.37 7.36 7.32 7.32 6.59 6.59 6.58 6.55 6.54 6.54.0 0.5 3 0.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 f (ppm) 5.0 4.5 4.0 3.5 3.0 2.5 2.0.5.0 0.5 0.0 63.8 47.5 43.82 20.24 2.33 60 50 40 30 20 0 00 90 80 f (ppm) 70 60 50 40 30 20 0 0 3

Methyl benzoate (4a): 32

Methyl 4-methoxybenzoate (4b): 33

Methyl 2-fluorobenzoate (4c): 34

Methyl 4-aminobenzoate (4d): 3 67.28 5.02 3.6 9.52 3.79 5.64 70 60 50 40 30 20 0 00 90 80 f (ppm) 70 60 50 40 30 20 0 0 35

Methyl 5-methylthiophene-2-carboxylate (4e): 36

Ethyl benzofuran-2-carboxylate (4f): O O O 37

Dihydro β-ionic Acid (5a):.90 2.0 2.03 3.0 2.00 2.09 6.07 2.43 2.4 2.4 2.40 2.40 2.39 2.37 2.36 2.36 2.34 2.34.93.9.89.6.57.55.44.43.42.00 7.2 7.0 6.6 6.2 5.8 5.4 5.0 4.6 4.2 3.8 f (ppm) 3.4 3.0 2.6 2.2.8.4.0 3 80.30 35.45 28.53 39.7 34.98 34.77 32.72 28.38 23.50 9.65 9.4 80 70 60 50 40 30 20 0 00 f (ppm) 90 80 70 60 50 40 30 20 38

HRMS 39

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