Lipase catalyzed condensation reaction of 4-nitrobenzaldehyde with acetyl acetone
in aqueous-organic co-solvent mixtures and in nearly anhydrous media
Abir B. Majumder and Munishwar N. Gupta*
Supporting information:
S 1: Screening of organic co-solvents
S 2: 1H-NMR spectra of the 2:2 adduct (4)
S 3:D2O exchanged 1H-NMR spectra of the 2:2 adduct (4)
S 4: 13C NMR spectra of the 2:2 adduct (4, scheme 2)
S 5: 13C DEPT spectra of the 2:2 adduct (4, scheme 2)
S 6: HRMS of deuterated product (4)
S 7: 1H-NMR spectra of the cyclized 2:2 adduct (5)
S 8: Conversion-time plot (HPLC) used for the study of initial rates
90
80
70
Conversion (%)
60
50
40
30 % DMF
30 % Dioxan
30 % DMSO
30
20
10
0
0
20
40
60
80
Time (h)
S 1 Screening of organic co-solvents for the lipase catalyzed synthesis of 4: 4Nitrobenzaldehyde (100 mM), acetylacetone (100 mM), 20 mg Lipase (Mucor Javanicus
lipase), in presence of co-solvents (30 % v/v, required to dissolve the aldehyde and
acetylacetone in 1 mL buffer) were shaken at 200 rpm at 30 °C. Aliquots were taken out
at different time intervals and were analyzed by HPLC. Each experiment was performed
thrice and the deviation between the individual values within ± 2%.
2
ppm
S 2 1H-NMR spectra (CDCl3, 300 MHz) of the 2:2 adduct 4.
3
S 3 D2O exchanged 1H-NMR spectra (CDCl3, 300 MHz) of the 2:2 adduct 4. The enolic
protons (at δ 5.3 ppm) were disappeared by deuterium exchange.
4
S 4 13C- NMR Spectra (CDCl3, 300 MHz) of the 2:2 adduct 4
5
S 5 13C DEPT NMR (CDCl3, 300 MHz) Spectra of the 2:2 adduct 4 indicating a total of
five types of carbons bearing odd number of hydrogen atoms.
6
S 6 HRMS data of the product 4 (deuterated). m/z 509.3036 (M+ NaC24H22 D2 N2O9
requires 509.2027). The peak at 507.2543 was due to the mono deuterated 4 which
occurred with the proton exchange in methanol solution which was used as the solvent
for mass spectral analysis.
7
S 7: 1H-NMR spectra (CDCl3, 300 MHz) of the cyclic 2:2 adduct 5. The two enolic
protons (at δ 5.3 ppm, S 2) of 4 are missing showing removal of these two protons via
ring closure. The peak at δ 1.5 ppm is a moisture impurity.
8
100
100
Acetonitrile
90
1a
Acetonitrile
Acetylacetone
CPME
DMSO
DCM
t-butly alcohol
t-amyl alcohol
90
Acetylacetone
80
CPME
80
DMSO
70
DCM
t-butyl alcohol
60
Conversion (%)
Conversion (%)
70
1b
t-amyl alcohol
50
40
30
60
50
40
30
20
20
10
10
0
0
20
40
60
Time (h)
80
0
0
20
40
60
80
Time (h)
S 8. Effect of diffferent organic solvents on the synthesis of 4 (Fig 1a) and 3 (Fig 1b)
from acetylacetone and 4-nitrobenzaldehyde in low-water media. 4-Nitrobenzaldehyde
(0.1 M), 20 mg lipase formulation was taken in 1mL of various dried organic solvent
along with acetylacetone (0.1 M or in excess in solvent free case) and were shaken at 200
rpm at 30°C. Each experiment was performed thrice and the deviation between the
individual values within ± 2 %.
9