Subscribe to RSS
DOI: 10.1055/s-2003-36239
Polymer-Supported DMI as a Potential Heterogeneous Dehydrating Agent: Application to Esterification and Amidation
Publication History
Publication Date:
18 December 2002 (online)
Abstract
A new polymer-supported urea (P-DMI) (4) was prepared as a precursor for a new heterogeneous dehydrating agent, polymer-supported chloroamidinium chloride (P-DMC) (5). Application of 4 to esterification and amidation, after conversion to 5, efficiently afforded dehydrated products. No epimerization was practically observed in peptide synthesis. Compound 4 (P-DMI) was recovered as a re-useable form by simple filtration.
Key words
polymer-supported reagent - esterification - amidation - peptide synthesis - recyclability
- 1
Anastas PT.Warner JC. In Green Chemistry: Theory and Practice Oxford University Press; Oxford: 1998. -
2a
Isobe T.Ishikawa T. J. Org. Chem. 1999, 64: 5832 -
2b
Isobe T.Ishikawa T. J. Org. Chem. 1999, 64: 6984 -
2c
Isobe T.Ishikawa T. J. Org. Chem. 1999, 64: 6989 -
3a
Desai MC.Stramiello LMS. Tetrahedron Lett. 1993, 34: 7685 -
3b
Adamczyk M.Fishpaugh JR.Mattingly PG. Tetrahedron Lett. 1995, 36: 8345 -
3c
Huang W.Kalivretenos AG. Tetrahedron Lett. 1995, 36: 9113 -
3d
Balakrishnan T.Rajendran V. J. Polym. Sci., Part A: Polym. Chem. 1997, 35: 727 -
3e
Flynm DL.Crich JZ.Devraj RV.Hockerman SL.Parlow JJ.South MS.Woodard S. J. Am. Chem. Soc. 1997, 119: 4874 -
3f
Pop IE.Deprez BP.Tartar AL. J. Org. Chem. 1997, 62: 2594 -
3g
Dendrinos KG.Jeong J.Huang W.Kalivretenos AG. Chem. Commun. 1998, 499 -
3h
Dendrinos KG.Kalivretenos AG. Tetrahedron Lett. 1998, 39: 1321 -
3i
Buckman BO.Morrissey MM.Mohan R. Tetrahedron Lett. 1998, 39: 1487 -
3j
Sturio CF.Labelle M. Tetrahedron Lett. 1998, 39: 5891 -
3k
Parlow JJ.Flyn DL. Tetrahedron 1998, 54: 4013 -
3l
Adamczyk M.Fishpaugh JR.Mattingly PG. Tetrahedron Lett. 1999, 40: 463 -
3m
Kim K.Le K. Synlett 1999, 1957 -
3n
Masala S.Taddei M. Org. Lett. 1999, 1: 1355 -
3o
Balakrishnan T.Rajendran V. J. Appl. Polym. Sci. 2000, 78: 2075 -
3p
Chinchilla R.Dodsworth DJ.Najera C.Soriano JM. Tetrahedron Lett. 2000, 41: 2463 -
3q
Chinchilla R.Dodsworth DJ.Najera C.Soriano JM. Tetrahedron Lett. 2001, 42: 4487 - DMC (2) and its related chloroamidines could be reacted with primary and secondary amines to yield the corresponding guanidines and guanidinium salts, respectively. On the former see:
-
8a
Isobe T.Fukuda K.Ishikawa T. J. Org. Chem. 2000, 65: 7770 -
8b
Isobe T.Fukuda K.Tokunaga T.Seki H.Yamaguchi K.Ishikawa T. J. Org. Chem. 2000, 65: 7774 -
8c
Isobe T.Fukuda K.Yamaguchi K.Seki H.Tokunaga T.Ishikawa T. J. Org. Chem. 2000, 65: 7779 -
8d On the latter see:
Hada K.Watanabe T.Isobe T.Ishikawa T. J. Am. Chem. Soc. 2001, 123: 7705 -
9a
Akaji K.Kuriyama N.Kimura T.Fujiwara Y.Kiso Y. Tetrahedron Lett. 1992, 33: 3177 -
9b
Akaji K.Kuriyama N.Kiso Y. Tetrahedron Lett. 1994, 35: 3315 -
9c
Akaji K.Kuriyama N.Kiso Y. J. Org. Chem. 1996, 61: 3350 -
9d
Humphrey JM.Chamberlin AR. Chem. Rev. 1997, 97: 2243 - For the previous synthesis, see:
-
10a On CbzGly-l-PheOEt:
Saito T. Chem. Lett. 1975, 729 -
10b On Cbz-l-Phe-l-ProOMe:
Wante DPM.Anteunis MJO. Bull. Soc. Chim. Belg. 1984, 93: 73 -
10c See also:
Nishikata M.Yokosawa H.Ishii S. Chem. Pharm. Bull. 1986, 37: 2931 -
10d
Schmidt U.Kroner M.Beutler U. Synthesis 1988, 6: 475 -
10e On Cbz-l-Trp-l-ProOMe:
Moss RA.Chiang YP.Hui Y. J. Am. Chem. Soc. 1984, 106: 7506
References
Reaction time can be shortened from 3 d to 1 d by use of the corresponding iodide in place of the 4-chloromethyl polystyrene resin.
5Conversion of the starting polystyrene derivative to P-DMI (4) was estimated by relative peak ratio between carbonyl (at δ = 162 ppm) and aromatic carbon absorptions (at δ = 128 ppm) in the product using solid 13C NMR technique, in addition to combustion analysis. Details will be reported elsewhere.
6
Typical Procedure
(entries 2 and 3 in Table 1):
A mixture of P-DMI(4) (984 mg) and oxalyl chloride
(1.71
mmol) in benzene (10 mL) was refluxed for 24 h, cooled to r.t. and
evaporated in vacuo to yield crude P-DMC (5)
(1.19 g, 88% conversion).
To a suspension of crude 5 (1.19 g), dihydrocinnamic acid (1.0 mmol)
in CH2Cl2 (10 mL) were added t-butyl
alcohol (1.0 mmol) and Et3N (5.0 mmol), and then the
suspension was stirred at r.t. for 48 h. The polymer was recovered
by filtration and washing with CH2Cl2. The
filtrate and washings were combined, washed with 1 N HCl, sat. NaHCO3,
H2O and sat. NaCl, dried ( over MgSO4), and evaporated.
Purification of the crude product by distillation (bp 110 °C/2.0
mmHg) yielded the corresponding ester, 166 mg (80%), as
a colorless oil. The recovered 4 was successively
washed with 1 N HCl, H2O, MeOH, and CH2Cl2,
and dried at 40 °C.
Esterification of
dihydrocinnamic acid with t-butyl alcohol using
a recycled 4, after chlorination, under
the same conditions described above yielded t-butyl
dihydro-cinnamate in 81% yield.
Reaction under heating led to the formation of the corresponding polymer-bound guanidine [8] as a side product, which could be estimated in ca. 15% yield by FT-IR.