References
1a
D’Arrigo P.
Pedrocchi-Fantoni G.
Servi S.
Adv. Appl. Microbiol.
1997,
44:
81
1b
Csuk R.
Glänzer BI.
Yeast-Mediated Stereoselective Biocatalysis, In Stereoselective Biocatalysis
Patel RN.
Marcel-Dekker;
New York:
2000.
Chap. 19.
p.527
1c
Davey CL.
Powell LW.
Turner NJ.
Wells A. In Preparative Biotransformations
Roberts SM.
John Wiley and Sons;
Chichester:
1994.
Chap. 2.
p.8
2
Hudlicky M. In Reductions in Organic Chemistry
American Chemical Society;
Washington DC:
1999.
Chap. 8.
p.91
3a
Navarro-Ocaña A.
Jiménez-Estrada M.
González-Paredes M.
Bárzana E.
Synlett
1996,
695
3b
Navarro-Ocaña A.
Olguín LF.
Luna H.
Jiménez-Estrada M.
Bárzana E.
J. Chem. Soc., Perkin Trans. 1
2001,
2754
4
Kapinos L.
Sigel H.
Eur. J. Inorg. Chem.
1999,
1781
5
Sarlauskas J.
Dickancaite E.
Nemeikaite A.
Anusevicius Z.
Nivinskas Segura-Aguilar HJ.
Cenas N.
Arch. Biochim. Biophys.
1997,
346:
219
6
Zou R.
Ayres KR.
Drach JC.
Townsend LB.
J. Med. Chem.
1996,
39:
3477
7
Purygin PP.
Sergeeva LI.
KuzŽmina VE.
Labazova ON.
Pharm. Chem. J.
2002,
36 (8):
415.
8
Njoya Y.
Boufatah N.
Gellis A.
Rathelot P.
Crozet PM.
Vanelle P.
Heterocycles
2002,
57 (8):
1423
9
Dincer S.
Dyes Pigm.
2002,
53:
263
10
Rodembusch FS.
Buckup T.
Segala M.
Tavares L.
Bordalo-Correia RR.
Stefani V.
Chem. Phys.
2004,
305:
115
11a
Brain CT.
Steer JT.
J. Org. Chem.
2003,
68:
6814
11b
Brain CT.
Brunton SA.
Tetrahedron Lett.
2002,
43:
1893
12
Esser F.
Ehrengart P.
Ignatow HP.
J. Chem. Soc., Perkin Trans. 1
1999,
1153
13a
Kihel AE.
Benchidmi M.
Essassi EM.
Danion-Bougot R.
Synth. Commun.
1999,
29:
387
13b
Chauhan PMS.
Bhakuni DS.
Indian. J. Chem., Sect. B
1986,
25:
1146
14a
Thomas JB.
Fall MJ.
Cooper JB.
Burgess JP.
Carroll FI.
Tetrahedron Lett.
1997,
29:
5099
14b
Patel KM.
Patel VH.
Patel MP.
Patel RG.
Dyes Pigm.
2002,
55:
53
14c See ref.5 and ref.10
15a
Porter HK.
Org. React.
1973,
20:
455
15b
Terpko MO.
Heck RF.
J. Org. Chem.
1980,
45:
4992
16
Phillips MA.
J. Chem. Soc.
1928,
2393
17
Vogel’s Textbook of Practical Organic Chemistry
5th ed.:
Furniss BS.
Hannaford AJ.
Smith PWG.
Tatchell AR.
Longman;
London:
1989.
18
Representative Reduction of Substituted 2,4-Dinitro-
N
-acylanilines with Baker’s Yeast.
In a typical experiment, the substrate 2,4-dinitroacylaniline 1e (0.5 mmol) was dissolved in 5 mL of acetone-EtOH 1:1 v/v and the resulting solution was added to a prehydrated (30 min) suspension of 10 g dried yeast (Saf-instant) in 100 mL of 0.5 M phosphate buffer (pH = 7.5) and containing 10 g of sucrose at 30 °C. The mixture was stirred on an orbital shaker (150 rpm) and the pH was kept constant by adding portions of 0.5 M NaOH. The stirring was continued until all the substrate was consumed or remained unchanged as judged by TLC. The mixture was then saturated with NaCl, diluted with 100 mL of EtOAc and combined with 20 g of celite. After vigorous stirring, the cells were removed by vacuum filtration over a bed of celite, the two phases of the filtrate were separated and the aqueous layer extracted with EtOAc (3 × 100 mL); the filter cake was rinsed with EtOAc (3 × 100 mL) and the combined organic extracts were dried over anhyd Na2SO4 and concentrated in vacuo. The resulting oil was purified by column chromatography on silica gel. Elution with CH2Cl2-MeOH (95:5) yielded 2-amino-4-nitroacylaniline 2e:
1H NMR (300 MHz, CDCl3-d
6-DMSO): δ = 9.14 (1 H, s, NH), 7.73 (1 H, d, J = 9.0 Hz, ArH6), 7.65 (1 H, d, J = 2.7 Hz, ArH3), 7.47 (1 H, dd, J
5-6 = 8.8 Hz, J
5-3 = 2.8 Hz, ArH5), 5.05 (2 H, s, NH2), 2.44 (2 H, t, CH2, C-1), 2.44 (2 H, sext, CH2, C-3), 1.69 (2 H, q, CH2, C-2), 0.95 (2 H, t, CH3, C-4). 13C NMR (75 MHz, CDCl3-d
6-DMSO): δ = 172.00, 144.17, 140.11, 129.78, 123.03, 111.83, 110.171, 35.92, 27.14, 21.75, 13.33. IR (KBr): νmax = 3452 (Ar-NH2), 3374, 3255
(-NH), 2916, 2847 (CH2, CH3), 1653 (C=O), 1347
(Ar-NO2), 876, 739 (NH2, Ar) cm-1. MS (EI): m/z (%) = 237 (40) [M+], 180 (12), 177 (29), 153 (100), 107 (12), 85 (25), 57 (35). Yield: 214 mg (90%); mp 123-125 °C.
A typical example for the cyclization of 2-amino-4-nitro-acylanilines into substituted nitrobenzimidazoles is as follows: 2,4-dinitroacylaniline 2e (118.5 mg, 0.5 mmol) was dissolved in 5 mL of glacial acetic acid and then this solution was carried out at 60 °C for 6 h. After completion, the solution was concentrated in a rotary evaporator to remove the HOAc and the residue was recrystallized from MeOH-H2O to afford 2-butyl-6-nitrobenzimidazole (3e):
1H NMR (300 MHz, CDCl3-d
6-DMSO): δ = 12.14 (1 H, s, NH1), 8.50 (1 H, d, J
7-5 = 2.0 Hz, ArH7), 8.19 (1 H, dd, J
5-4 = 8.8 Hz, J
5-7 = 2.0 Hz, ArH5), 7.60 (1 H, d, J
4-5 = 8.8 Hz, ArH4), 3.00 (2 H, t, CH2, C-1), 1.89 (2 H, q, CH2, C-2), 1.46 (2 H, sext, CH2, C-3), 0.96 (3 H, t, CH3, C-4). 13C NMR (75 MHz, CDCl3-d
6-DMSO): δ = 159.59, 142.50. 114.44, 118.48, 143.57, 111.56, 138.41, 29.95, 29.21, 22.42, 13.69. IR (KBr): ν = 3430 (NH), 3000-2800 (NH), 2980, 2939 (CH2, CH3), 1625 (Ar), 1592, 1472, 1452 and 1418 (C=N and C=C), 1514 and 1341 (Ar-NO2), 825, 734 (Ar) cm-1. MS (EI): m/z (%) = 219 (6) [M+], 218 (1), 204 (5), 190 (24), 177 (100), 158 (7), 144 (12), 131 (32). Yield: 98.5 mg (90%); mp 134-135 °C (Lit.19 139-141 °C).
19
Ries WJ.
Mihm G.
Narr B.
Hasselbach KM.
Wittneben H.
Entzeroth M.
van Meel JCA.
Wienen W.
Hauel NH.
J. Med. Chem.
1993,
36:
4040