Molbank 2007, M552

http://www.mdpi.org/molbank/

 

3-(2-Oxopropyl)-2(3H)-benzoxazolone

 

Ognyan I. Petrov*, Yordanka B. Ivanova, Mariana S. Gerova and Katya V. Petrova

 

Sofia University, Faculty of Chemistry, Department of Applied Organic Chemistry, 1 James Bourchier Ave., 1164 Sofia, Bulgaria

* Author to whom correspondence should be addressed. E-mail: [email protected]

 

Received: 9 March 2007 / Accepted: 19 March 2007 / Published: 30 May 2007

 

Keywords: phase transfer catalysis, Benzyltriethylammonium chloride (TEBA), benzoxazolone

 

 

The title compound is an important intermediate for the preparation of 3,4- and 3,4,5-substituted 1‑(2‑hydroxy-phenyl)imidazolin-2-ones [1, 2] and 6-methyl-4-(2-hydroxyphenyl)-1,2,4-triazin-3-ones [3]. According to literature data, the product 3 is prepared from 2(3H)-benzoxazolone with commercially unavailable bromoacetone in abs. ethanol in the presence of sodium ethoxide [4, 5]. We present an improve method for the synthesis of 3-(2-oxopropyl)-2(3H)-benzoxazolone (3) from available starting materials 1 and 2 under PTC conditions in higher yield.

 

To a mixture of 2(3H)-benzoxazolone (6.75 g, 50 mmol), fine powdered potassium carbonate (4.14 g, 30 mmol) and TEBA (200 mg) in DMF (15 ml), chloroacetone (4 ml, 50 mmol) was added. The reaction mixture was stirred for 1 h at 20-25 0C and then poured under stirring into 150 ml of water. The resulting precipitate was filtered and washed with water. Recrystallization from ethanol gave the product 3 as colorless needles. Yield: 90%.

 

Melting point: 119-120 0C

 

Elemental Analysis: Calculated for C10H9NO3: C 62.82%, H 4.74%, N 7.33%. Found: C 62.95%, H 4.53%, N 7.17%.

 

IR (nujol, cm-1): 1770, 1720 (CO).

 

1H-NMR (250 MHz, CDCl3): 2.25 (s, 3H, CH3); 4.61 (s, 2H, CH2); 6.77-7.21 (m, 4H, arom. H).

 

13C-NMR (63 MHz, CDCl3): 26.9 (CH3CO); 50.7 (CH2CO); 108.2 (C7); 109.9 (C4); 122.7 (C5); 123.8 (C6); 142.4 (C7a); 154.3 (C2); 199.8 (CH2CO).

 

MS (m/z, %): 191 [M+] (47); 148 (67); 120 (12); 104 (11); 77 (100); 65 (10); 50 (19).

 

References
  1. Lozanova, Ch.; Kalcheva, V.; Simov, D. Khim. Geterosikl. Soedin. 1988, 10, 1362.
  2. Lozanova, Ch.; Kalcheva, V. J. Prakt. Chem. 1989, 331(6), 1007.
  3. Bojtscheva, Ch.; Simov, D.; Kaltscheva, V. J. Prakt. Chem. 1979, 321(2), 226.
  4. Zinner, H.; Randow, F. J. Prakt. Chem. 1961, 4, 144.
  5. Simov, D. A.; Kalcheva, V.B.; Boycheva, H.S. Compt. Rend. Acad. Bulg. Sci. 1974, 27, 1073.
 

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