Synlett 2010(20): 3049-3052  
DOI: 10.1055/s-0030-1259051
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A Convenient, One-Pot Procedure for the Preparation of Acyl and Sulfonyl Fluorides Using Cl3CCN, Ph3P, and TBAF(t-BuOH)4

Joong-Gon Kima, Doo Ok Jang*b
a Biotechnology Division, Hanwha Chemical R&D Center, Daejeon 305-345, South Korea
b Department of Chemistry, Yonsei University, Wonju 220-710, South Korea
Fax: +82(33)7602182; e-Mail: dojang@yonsei.ac.kr;
Further Information

Publication History

Received 29 September 2010
Publication Date:
17 November 2010 (online)

Abstract

Various carboxylic acids were converted into acyl fluorides in excellent yields by treatment with trichloroacetonitrile, triphenylphosphine, and TBAF(t-BuOH)4 at room temperature. The reaction was applicable to the preparation of acid-sensitive amino acid fluorides without deprotection or rearrangement.

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Typical experimental procedure: To a mixture of benzoic acid (1.22 g, 10 mmol) and Ph3P (5.26 g, 20 mmol) in MeCN (25 mL) under argon, was added Cl3CCN (2 mL, 20 mmol) dropwise at r.t. The reaction mixture was stirred at r.t. for
1 h. TBAF(t-BuOH)4 (11.2 g, 20 mmol) was added to the above solution, and stirring was continued for 1 h at r.t. After concentration of the reaction mixture by using a rotary evaporator, the residue was purified by distillation under reduced pressure to give benzoyl fluoride (1.12 g, 91%;
bp 88-90 ˚C/100 mmHg (Lit.¹³c 84-86 ˚C/98 mmHg).