In-Water and Neat Batch and Continuous-Flow Direct ... mixture of a 2.0 M aqueous solution of p-phenol sulfonic acid (14.5 mL; 29.0 mmol), an 37 % aqueous solution of formaldehyde

SUPPORTING INFOMATION

In-Water and Neat Batch and Continuous-Flow Direct Esterification and Transesterification by a Porous Polymeric Acid Catalyst

Heeyoel Baek1,3, Maki Minakawa1, Yoichi M. A. Yamada1,*, Jin Wook Han3, and Yasuhiro Uozumi1,2,*

1 RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan 2 Institute for Molecular Science (IMS), Myodaiji, Okazaki, Aichi 444-8787, Japan 3 Department of Chemistry, Hanyang University, Seoul 04763, Korea * [email protected], [email protected]

General Information:

All reagents, purchased from TCI, Aldrich, Wako, MERCK, and Fluka, were used without further

purification. Water was deionized with a Millipore system as a Milli-Q grade. NMR spectra

were recorded with JEOL JNM-AL500 spectrometer (500 MHz) and JEOL JNM-AL400

spectrometer (400 MHz) in CDCl3 at 25 °C. For 1H NMR spectra, proton chemical shifts (δ) are

given in ppm relative to tetramethylsilane (0.00 ppm) in CDCl3. Multiplicities are indicated by s

(singlet), d (doublet), t (triplet), m (multiplet), and br (broad). For 13C NMR spectra, carbon

chemical shifts were internally referenced to the deuterated solvent signal of CDCl3 (77.16 ppm).

Mass spectra were recorded with Accu TOF GC (JEOL JMS-100GC). SEM images were obtained

by using a scanning electron microscope (Hitachi TS3030Plus). EDX (Energy dispersive X-ray

spectroscopy) analyses were recorded on Bruker nanoGmbH Quantax 70. BET

(Brunauer-Emmett-Teller) surface area analysis was performed on BELSORP-36 (BEL JAPAN,

INC). ATR-IR spectra were taken with JASCO Fourier Transform Infrared Spectrometer-6200.

Amberlyst® 16 wet : CAS: 125004-35-5, H+-form , strongly acidic (Fluka)

DOWEX: CAS: 69011-20-7, 50WX2-100-200 mesh (H) Cation Exchange Resin (Sigma-Aldrich)

S-1

MS3A: CAS: 308080-99-1, 1/16˝ rod, 3 Å pore diameter (Wako)

p-phenolsulfonic acid: CAS:98-67-9, >85.0% (TCI)

p-TsOH: CAS: 6192-52-5 (Wako)

S-2

Experimental Section:

Preparation of a porous PAFR 1a and 1b

A mixture of a 2.0 M aqueous solution of p-phenol sulfonic acid (14.5 mL; 29.0 mmol), an 37 %

aqueous solution of formaldehyde (14.3 mL; 145 mmol) was stirred in a 300 mL flask with a reflux

condenser at 120 °C (oil bath temperature) for 6 h under refluxing conditions. The flask was

gradually cooled down to 25 °C in 12 h (for 1a) or in 5 min (for 1b) on an oil bath (for 1a) or an

ice-water bath (for 1b) to give a pale brownish gel. The obtained gel material was washed with

methanol and acetone, and then was dried under reduced pressure. A hardly soluble polymer

PAFR 1a was obtained in 72% yield (3.6 g) as a reddish brown solid. ATR-IR ν 3376, 1598, 1469,

1032, 773, 750, 708, 612 cm-1; Anal. Calcd. for (C35H30O8S•6H2O)n: C, 58.49; H, 5.89; S, 4.46.

Found: C, 57.78; H, 5.42; S, 4.08. 1b: Anal. Calcd. for (C35H30O8S•2H2O)n: C, 65.00; H, 5.30; S,

4.96. Found: C, 64.82; H, 5.67; S 2.99.

S-3

Figure S1. IR spectrum of 1a and IR spectrum simulation of 1,2,3-trisubstituted benzenes

(550-1000 cm-1)

Figure S2. Kr-adsorption isotherm for 1a and 1b

General procedure for the direct esterification under solvent-free conditions

Figure 3:

To a 4 mL vial was added a p-phenol sulfonic acid-formaldehyde catalyst 1a, 1b (0.7 mol%, 5.6

mg) or commercial available homogeneous and heterogeneous catalysts (0.7 mol%), a benzyl

alcohol 2a (1.0 mmol), and acetic acid (1.2 mol equiv). The mixture was shaken by a shaker (16

Hz, Petisyzer) for 12 h at 50°C. During the reaction, the reaction mixture was monitored with GC

with decane as an internal standard.

Table 1:

To a 4 mL vial was added a p-phenol sulfonic acid-formaldehyde catalyst 1a (0.7 mol%, 5.6 mg),

S-4

an alcohol 2 (1.0 mmol), and acetic acid (1.2 mol equiv). The mixture was shaken by a shaker (16

Hz, Petisyzer) for 12 h at 50-80 °C. After the reaction, the catalyst 1a was filtered by filtration and

washed with acetone. The filtrate was evaporated to give the corresponding acetate 3.

Table 2:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (0.7 mol%, 5.6 mg), a

carboxylic acid 4 (1.0 mmol), and methanol (5 mol equiv). The mixture was shaken by a shaker

(16 Hz, Petisyzer) for 12 h at 50-60 °C. After the reaction, the catalyst 1a was filtered by filtration

and washed with acetone. The filtrate was evaporated to give the corresponding methyl esters 5.

General procedure for the esterification in water

Table 3:

To a 4 mL vial was added a p-phenol sulfonic acid-formaldehyde catalyst 1a (3 mol%, 24 mg), an

alcohol 2 (1.0 mmol), and acetic acid (5 mol equiv) in water (3.0 M). The mixture was shaken by

a shaker (16 Hz, Petisyzer) for 48 h at 80 °C. After the reaction, the catalyst 1a was filtered by

filtration and washed with acetone. The filtrate was evaporated to give the corresponding acetate

3.

Table 4:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (3 mol%, 24 mg), a carboxylic

acid 4 (1.0 mmol), and an alcohol (10 mol equiv) in water (3.0 M). The mixture was shaken by a

shaker (16 Hz, Petisyzer) for 48 h at 80 °C. After the reaction, the catalyst 1a was filtered by

filtration and washed with acetone. The filtrate was evaporated to give the corresponding methyl

esters 5.

S-5

Figure 4:

Esterification:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (0.7 mol%, 5.6 mg), a decanoic

acid 4b (1.0 mmol), and an alcohol (10 mol equiv). The mixture was shaken by a shaker (16 Hz,

Petisyzer) for 24 h at 50 °C. During the reaction, the reaction mixture was monitored by GC with

decane as a internal standard.

Hydrolysis:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (0.7 mol%, 5.6 mg), a methyl

decanoate 5b (1.0 mmol), and an H2O (10 mol equiv). The mixture was shaken by a shaker (16

Hz, Petisyzer) for 24 h at 50 °C. During the reaction, the reaction mixture was monitored by GC

with decane as a internal standard.

General procedure for the transesterification

Figure 5:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a, 1b (0.7 mol%, 5.6 mg) or

commercial available heterogeneous catalysts (0.7 mol%), 2d (1.0 mmol), and ethyl acetate (10 mol

equiv). The mixture was shaken by a shaker (16 Hz, Petisyzer) for 24 h at 80 °C without removal

of ethanol. During the reaction, the reaction mixture was monitored by GC with decane as an

internal standard.

Table 5:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (0.7 mol%, 5.6 mg), 2 (1.0

S-6

mmol), and ethyl acetate (10 mol equiv). The mixture was shaken by a shaker (16 Hz, Petisyzer)

for 24 h at 80 °C without removal of ethanol. After the reaction, the catalyst 1a was filtered by


esters 3.

Table 6:

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (0.7 mol%, 5.6 mg), 6 (1.0

mmol), and methanol (10 mol equiv) without removal of ethanol. The mixture was shaken by a

shaker (16 Hz, Petisyzer) for 24 h at 80 °C. After the reaction, the catalyst 1a was filtered by


esters 5.

Synthesis of biodiesel fuel (FAME):

To a 4 mL vial was added p-phenol sulfonic acid-formaldehyde 1a (0.7 mol%, 5.6 mg) or

commercially available homogeneous and heterogeneous acid catalyst (0.7 mol%), oleic acid (1.0

mmol), and methanol (5 mol equiv). The mixture was shaken by a shaker (16 Hz, Petisyzer) for

12 h at 60 °C. After the reaction, the catalyst 1a was filtered by filtration and washed with acetone.

The filtrate was evaporated to give the corresponding biodiesel fuel 5g.

Continuous flow reaction:

The acid catalyst 1a (900 mg, 1.1 mmol) was packed into a glass column (15 cm× 6.6 mm bed

reactor) that was attached to a heat block. A solution of the mixture of oleic acid and methanol

was installed with a flow pump through capillary tubing. The flow reaction of oleic acid and

S-7

methanol (5 mol equiv) was carried at a flow rate of 10 µL/min through the 1a-packed column at

80 °C (residence time: 18 min). The reaction mixture solution was collected from the outlet of

column, and evaporated to give the corresponding biodiesel fuel 5g in 92-96% conversion.

1H and 13C NMR data of products

benzyl acetate (3a)

O

O

1H NMR (500 MHz, CDCl3): δ 2.10 (s, 3H), 5.11 (s, 2H), 7.31-7.39 (m, 5H). 13C NMR (125 MHz,

CDCl3): δ 21.2, 66.5, 128.4, 128.7, 136.1, 171.0. GC-TOF HRMS: calcd for C9H10O2 [M]+

150.0681, found 150.0672.

2-phenyl ethyl acetate (3b)

O

O

1H NMR (500 MHz, CDCl3): δ 2.04 (s, 3H), 2.94 (t, J=6.9 Hz, 2H), 4.28 (t, J=7.2 Hz, 2H),

7.21-7.32 (m, 5H). 13C NMR (125 MHz, CDCl3): δ 21.1, 35.2, 65.1, 126.7, 128.6, 129.0, 138.0,

171.2. GC-TOF HRMS: calcd for C10H12O2 [M]+ 164.0837, found 164.0846.

3-phenyl propyl acetate (3c)

O

O

1H NMR (500 MHz, CDCl3): δ 1.93-1.99 (m, 2H), 2.05 (s, 3H), 2.69 (t, J=7.7 Hz, 2H), 4.09 (t,

S-8

J=6.6 Hz, 2H), 7.18-7.21 (m, 3H), 7.26-7.30 (m, 2H). 13C NMR (125 MHz, CDCl3): δ 21.1, 30.3,

32.3, 64.0, 126.2, 128.5, 128.6, 141.4, 171.3. GC-TOF HRMS: calcd for C11H14O2 [M]+ 178.0994,

found 178.0989.

octyl acetate (3d)

O

O

1H NMR (500 MHz, CDCl3): δ 0.88 (t, J=6.9 Hz, 3H), 1.22-1.38 (m, 10H), 1.59-1.65 (m, 2H), 2.05

(s, 3H), 4.05 (t, J = 6.9 Hz, 2H). 13C NMR (125 MHz, CDCl3): δ 14.2, 21.2, 22.8, 26.1, 28.8, 29.3,

29.4, 31.9, 64.8, 171.4. GC-TOF HRMS: calcd for C10H20O2 [M]+ 172.1463, found 172.1491.

decyl acetate (3e)

O

O



29.4, 29.7, 29.7, 32.0, 64.8, 171.4. GC-TOF HRMS: calcd for C12H24O2 [M]+ 200.1776, found

200.1815.

dodecyl acetate (3f)

O

O



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29.5, 29.7, 29.7, 29.8, 29.8, 32.1, 64.8, 171.4. GC-TOF HRMS: calcd for C14H28O2 [M]+ 228.2089,

found 228.2105.

3,7-dimethyloctyl acetate (3g)

O

O

1H NMR (500 MHz, CDCl3): δ 0.87 (d, J=6.9 Hz, 6H), 0.90 (d, J=6.9 Hz, 3H), 1.10-1.16 (m, 3H),

1.21-1.34 (m, 3H), 1.39-1.46 (s, 1H), 1.48-1.56 (m, 2H), 1.62-1.69 (m, 1H), 2.04 (s, 3 H), 4.05-4.15

(m, 2H). 13C NMR (125 MHz, CDCl3): δ 19.7, 21.2, 22.7, 22.8, 24.7, 28.1, 30.0, 35.6, 37.3, 39.4,

63.3, 171.4. GC-TOF HRMS: calcd for C12H24O2 [M]+ 200.1773, found 200.1768.

cyclohexyl acetate (3h)

O

O

1H NMR (500 MHz, CDCl3): δ 1.21−1.28 (m, 1H), 1.32-1.44 (m, 3H), 1.52-1.57 (s, 2H), 1.70-1.75

(m, 2H), 1.84-1.87 (m, 2H), 2.03 (s, 3H) 4.71-4.76 (m, 1H). 13C NMR (125 MHz, CDCl3): δ 21.6,

24.0, 25.5, 31.8, 72.8, 170.8. GC-TOF HRMS: calcd for C8H14O2 [M]+ 142.0994, found 142.0976.

cyclooctyl acetate (3i)

O

O

1H NMR (500 MHz, CDCl3): δ 1.45-41.84 (m, 14H), 2.02 (s, 3H), 4.93 (sept, J = 4.2 Hz, 1H). 13C

NMR (125 MHz, CDCl3): δ 21.7, 23.1, 25.5, 27.2, 31.6, 75.6, 170.7. GC-TOF HRMS: calcd for

C10H18O2 [M]+ 170.1307, found 170.1323.

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octan-2-yl acetate (3j)

O

O

1H NMR (500 MHz, CDCl3): δ 0.88 (t, J=6.9 Hz, 3H), 1.20 (d, J=6.3 Hz, 3H), 1.22-1.35 (m, 8H),

1.41-1.50 (m 1H), 1.54-1.62 (m, 1H), 2.03 (s, 3 H), 4.89 (sext, J=6.3 Hz, 1H). 13C NMR (125 MHz,

CDCl3): δ 14.2, 20.1, 21.4, 22.7, 25.5, 29.2, 31.9, 36.1, 71.6, 171.0. GC-TOF HRMS: calcd for

C10H18O2 [M]+ 172.1463, found 172.1447.

hexadecyl acetate (3k)

O

O



29.3, 29.5, 29.5, 29.6, 29.6, 29.7, 31.9, 64.6, 171.1. GC-TOF HRMS: calcd for C18H36O2 [M]+

284.2715, found 284.2710.

4-methylbenzyl acetate (3l)

1H NMR (400 MHz, CDCl3): δ 2.08 (s, 2H), 2.35 (s, 3H), 5.06 (s, 2H), 7.16-7.25 (m, 4H). 13C NMR

(100 MHz, CDCl3): δ 21.0, 21.2, 66.2, 128.4, 129.2, 132.9, 138.1, 170.9. GC-TOF HRMS: calcd for

C10H12O2 [M]+ 164.0837, found 164.0839.

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2-methylbenzyl acetate (3m)

1H NMR (400 MHz, CDCl3): δ 2.10 (s, 3H), 2.35 (s, 3H), 5.12 (s, 2H), 7.20-7.33 (m, 4H). 13C

NMR (100 MHz, CDCl3): δ 18.8, 20.9, 64.7, 126.0, 128.5, 129.2, 130.3, 133.8, 136.9, 172.7.

GC-TOF HRMS: calcd for C10H12O2 [M]+ 164.0837, found 164.0840.

2-methoxybenzyl acetate (3n)


(100 MHz, CDCl3): δ 21.0, 55.3, 61.7, 110.4, 120.3, 124.2, 129.5, 129.7, 157.4, 170.9. GC-TOF

HRMS: calcd for C10H12O3 [M]+ 180.0786, found 180.0759.

3-methoxybenzyl acetate (3o)


(100 MHz, CDCl3): δ 20.9, 55.2, 66.1, 113.6, 113.7, 120.4, 129.6, 137.4, 159.7, 170.8. GC-TOF

HRMS: calcd for C10H12O3 [M]+ 180.0786, found 180.0799.

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4-chlorobenzyl acetate (3p)

1H NMR (400 MHz, CDCl3): δ 2.10 (s, 3H), 5.06 (s, 2H), 7.31-7.39 (m, 4H). 13C NMR (100 MHz,

CDCl3): δ 20.9, 65.5, 128.8, 129.6, 134.2, 134.4, 170.8. GC-TOF HRMS: calcd for C9H9ClO2 [M]+

184.0291, found 184.0293.

4-nitrobenzyl acetate (3q)

O2N

OCOMe

1H NMR (400 MHz, CDCl3): δ 2.15 (s, 3H), 5.20 (s, 2H), 7.53 (d, J = 8.7 Hz, 2H), 8.24 (d, J = 8.7

Hz, 2H). 13C NMR (100 MHz, CDCl3): δ 20.9, 29.7, 64.8, 123.8, 128.4, 143.2. GC-TOF HRMS:

calcd for C9H9O4N [M]+ 195.0531, found 195.0578.

methyl octanoate (5a)

OMe

O

1H NMR (500 MHz, CDCl3): δ 0.88 (t, J = 6.9 Hz, 3H), 1.22-1.34 (m, 8H), 1.59-1.65 (m, 2H), 2.30

(t, J = 7.5 Hz, 2H), 3.67 (s, 3H). 13C NMR (125 MHz, CDCl3): δ 14.2, 22.7, 25.1, 29.1, 29.3, 31.8,

34.3, 51.6, 174.5. GC-TOF HRMS: calcd for C9H18O2 [M]+ 158.1307, found 158.1340.

methyl decanoate (5b)

S-13

OMe

O

1H NMR (500 MHz, CDCl3): δ 0.88 (t, J = 6.9 Hz, 3H), 1.22-1.35 (m, 10H), 1.59-1.65 (m, 2H),

2.30 (t, J = 7.5 Hz, 2H), 3.67 (s, 3H). 13C NMR (125 MHz, CDCl3): δ 14.2, 22.8, 25.1, 29.3, 29.4,


186.1639.

methyl dodecanoate (5c)

OMe

O




found 214.1935.

methyl hexadecanoate (5d)

OMe

O



29.5, 29.6, 29.7, 29.8, 29.8, 29.8, 29.8. 29.8, 32.0, 34.3, 51.6, 174.5. GC-TOF HRMS: calcd for

C17H34O2 [M]+ 270.2559, found 270.2559.

methyl octadecanoate (5e)

S-14

OMe

O



29.5, 29.6, 29.7, 29.8, 29.8, 29.8, 29.8. 29.8, 29.8, 29.8, 32.1, 34.3, 51.6, 174.5. GC-TOF HRMS:

calcd for C19H38O2 [M]+ 298.2872, found 298.2861.

methyl heptanoate (5f)

1H NMR (400 MHz, CDCl3): δ 0.88 (t, J = 7.1 Hz, 3H), 1.22-1.35 (m, 6H), 1.60-1.64 (m, 2H), 2.30

(t, J = 7.9 Hz, 2H), 3.67 (s, 3H). 13C NMR (100 MHz, CDCl3): δ 14.0, 22.4, 24.8, 28.8, 31.4, 34.1,

51.4, 174.3. GC-TOF HRMS: calcd for C8H16O2 [M]+ 144.1150, found 144.1144.

methyl oleate (5g)

OMe

O


1.99-2.02 (m, 4H), 2.30 (t, J = 7.7 Hz, 2H), 3.67 (s, 3H), 5.31-5.38 (m, 2H). 13C NMR (125 MHz,

CDCl3): δ 14.3, 22.8, 25.1, 27.3, 27.4, 29.2, 29.3, 29.3, 29.5, 29.5, 29.7, 29.8, 29.9, 32.1, 34.3, 51.6,

129.9, 130.2, 174.5. GC-TOF HRMS: calcd for C19H36O2 [M]+ 296.2715, found 296.2732.

octyl octanoate (6a)

S-15

O

O

1H NMR (500 MHz, CDCl3): δ 0.88 (m, 6H), 1.23-1.35 (m, 18H), 1.59-1.65 (m, 4H), 2.29 (t, J =

7.5 Hz, 2H), 4.06 (t, J = 6.9 Hz, 2H). 13C NMR (125 MHz, CDCl3): δ 14.2, 14.2, 22.8, 22.8, 25.2,

26.1, 28.8, 29.1, 29.3, 29.3, 29.4, 31.8, 31.9, 34.6, 64.6, 174.2. GC-TOF HRMS: calcd for C16H32O2

[M]+ 256.2402, found 256.2389.

butyl decanoate (6b)

O

O

1H NMR (400 MHz, CDCl3): δ 0.88 (m, 6H), 1.19-1.36 (m, 14H), 1.50-1.57 (m, 4H), 2.22 (t, J = 7.1

Hz, 2H), 4.00 (t, J = 6.3 Hz, 2H). 13C NMR (100 MHz, CDCl3): δ 13.7, 14.1, 19.1, 22.6, 25.0, 20.1,


found 228.2143.

methyl 4-phenylbutanoate (6c)

O

OMe

1H NMR (400 MHz, CDCl3): δ 1.98-2.05 (m, 2H), 2.39 (t, J = 7.6 Hz, 2H), 2.71 (t, J = 7.6 Hz, 2H),

3.72 (s, 3H), 7.22-7.25 (m, 3H), 7.31-7.35 (m, 2H). 13C NMR (100 MHz, CDCl3): δ 26.5, 33.4, 35.1,

51.5, 126.0, 128.4, 141.4, 174.0. GC-TOF HRMS: calcd for C11H14O2 [M]+ 178.0994, found

178.1005.

octyl 4-phenylbutanoate (6d)

S-16

O

O


1.90-2.00 (m, 2H), 2.32 (t, J = 7.8 Hz, 2H), 2.65 (t, J = 7.8 Hz, 2H), 4.06 (t, J = 6.6 Hz, 2H),

7.17-7.21 (m, 3H), 7.26-7.31 (m, 2H). 13C NMR (75 MHz, CDCl3): δ 14.1, 22.6, 25.9, 26.5, 28.6,

29.1, 31.7, 33.6, 35.1, 64.5, 125.9, 128.3, 128.4, 141.4, 173.5. GC-TOF HRMS: calcd for C18H28O2

[M]+ 276.2089, found 276.2141.

butyl 4-phenylbutanoate (6e)

O

OBu


1.92-2.00 (m, 2H), 2.32 (t, J = 7.2 Hz, 2H), 2.65 (t, J = 7.6 Hz, 2H), 4.07 (t, J = 6.8 Hz, 2H),

7.16-7.19 (m, 3H), 7.28-7.30 (m, 2H). 13C NMR (100 MHz, CDCl3): δ 14.0, 19.2, 26.6, 30.7, 33.7,


220.1448.

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SUPPORTING INFOMATION II

In-Water and Neat Batch and Continuous-Flow Direct Esterification and Transesterification by a Porous Polymeric Acid Catalyst

Heeyoel Baek1,3, Maki Minakawa1, Yoichi M. A. Yamada1,*, Jin Wook Han3, and Yasuhiro Uozumi1,2,*

1 RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan 2 Institute for Molecular Science (IMS), Myodaiji, Okazaki, Aichi 444-8787, Japan 3 Department of Chemistry, Hanyang University, Seoul 04763, Korea * [email protected], [email protected]

1H and 13C NMR spectra

S-18

O

O

O

O

S-19

O

O

O

O

S-20

O

O

O

O

S-21

O

O

O

O

S-22

O

O

O

O

S-23

O

O

O

O

S-24

O

O

O

O

S-25

O

O

O

O

S-26

O

O

O

O

S-27

O

O

O

O

S-28

O

O

O

O

S-29

OCOMe

OCOMe

S-30

OCOMe

OCOMe

S-31

OCOMe

OMe

OCOMe

OMe

S-32

OCOMeMeO

OCOMeMeO

S-33

Cl

OCOMe

Cl

OCOMe

S-34

O2N

OCOMe

O2N

OCOMe

S-35

OMe

O

OMe

O

S-36

OMe

O

OMe

O

S-37

OMe

O

OMe

O

S-38

OMe

O

OMe

O

S-39

OMe

O

OMe

O

S-40

OMe

O

OMe

O

S-41

OMe

O

OMe

O

S-42

O

O

O

O

S-43

O

O

O

O

S-44

OMe

O

OMe

O

S-45

OBu

O

OBu

O

S-46

O

O

O

O

S-47

Documents

In-Water and Neat Batch and Continuous-Flow Direct ... mixture of a 2.0 M aqueous solution of p-phenol sulfonic acid (14.5 mL; 29.0 mmol), an 37 % aqueous solution of formaldehyde