Abstract
Reaction of aryl aldehydes with 3-trimethylsilylindazole in the presence of CsF easily gave the corresponding 3-(arylhydroxymethyl)indazoles in good to moderate yields.
Keywords
aryl aldehydes - Brook rearrangement - cesium fluoride - indazoles - silyl compounds
References
1a
Bräse S.
Gil C.
Knepper K.
Bioorg. Med. Chem.
2002,
10:
2415 ; and references cited therein
1b
Fludzinski P.
Evrard DA.
Bloomquist WE.
Lacefield WB.
Pfeifer W.
Jones ND.
Deeter JB.
Cohen ML.
J. Med. Chem.
1987,
30:
1535
1c
Guillaume J.
Dumont C.
Laurent J.
Nedelec L.
Eur. J. Med. Chem.
1987,
22:
33
2a
Collot V.
Dallemagne P.
Bovy PR.
Rault S.
Tetrahedron
1999,
55:
6917
2b
Collot V.
Varlet D.
Rault S.
Tetrahedron Lett.
2000,
41:
4363
2c
Arnautu A.
Collot V.
Ros JC.
Alayrac C.
Wituski .
Rault S.
Tetrahedron Lett.
2002,
43:
2695
3
Claramunt RM.
Elguero J.
Garceran R.
Heterocycles
1985,
23:
2895
4a
Yeu J.-P.
Yeh J.-T.
Chen T.-Y.
Uang B.-J.
Synthesis
2001,
1775
4b
Zhang H.-C.
Derian CK.
Andrade-Gordon P.
Hoekstra WJ.
McComsey DF.
White KB.
Poulter BL.
Addo MF.
Cheung W.-M.
Damiano BP.
Oksenberg D.
Reynolds EE.
Pandey A.
Scarborough RM.
Maryanoff BE.
J. Med. Chem.
2001,
44:
1021
4c
Caron S.
Vazquez E.
Synthesis
1999,
588
4d
Dell’Erba C.
Novi M.
Petrillo G.
Tavani C.
Tetrahedron
1994,
50:
3529
4e
Krishnan R.
Lang SA.
Lin Y.
Wilkinson RG.
J. Heterocycl. Chem.
1988,
25:
447
4f
Shutske GM.
Allen RC.
Forsch MF.
Setescak LL.
Wilker JC.
J. Med. Chem.
1983,
26:
1307
4g
Ruchardt C.
Hassmann V.
Liebigs Ann. Chem.
1980,
908
4h
Wentrup C.
Damerius A.
Reichen W.
J. Org. Chem.
1978,
43:
2037
4i
García-Abbad E.
García-López MT.
García-Muñoz G.
Stud M.
J. Heterocycl. Chem.
1976,
13:
1241
4j
Hannig E.
Kollmorgen C.
Korner M.
Pharmazie
1976,
31:
534
4k
Dennler EB.
Frasca AR.
Tetrahedron
1966,
22:
3131
5
Grimmett MR. In Comprehensive Organic Chemistry
Vol. 4:
Barton DHR.
Ollis WD.
Sammes PG.
Pergamon;
New York:
1979.
Chap. 17.
p.382
6
Welch WM.
Hanau CE.
Whalen WM.
Synthesis
1992,
937
7
Shoji Y.
Hari Y.
Aoyama T.
Tetrahedron Lett.
2004,
45:
1769
8 No reaction occurred at r. t.
9 In fact, in the reaction of 3-trimethylsilylindazole(1 ) with PhCHO, the use of K2 CO3 in place of CsF as a base gave the desired product 5a (58 %) together with indazole(4 ) (37 %). Reaction conditions: PhCHO (10 equiv), K2 CO3 (1.5 equiv), MS 3Å, DMF, 80 °C, 6 h.
10 Probably, the Brook rearrangement giving the irreversible O -silyl intermediate 8 would accelerate this reaction.
11
Zhang H.-C.
Brumfield KK.
Maryanoff BE.
Tetrahedron Lett.
1997,
38:
2439
12
Couture A.
Deniau E.
Gimbert Y.
Grandclaudon P.
Tetrahedron
1993,
49:
1431