Crystal structure of ethyl [6-(2-fluorobenzoyl)-2-oxobenzothiazolin- 3-yl]-butanoate, C20H18FNO4S

C20H18FNO4S, monoclinic, P12i/nl (no. 14), a = 12.537(1) A , ft = 11.902(1) A , c = 12.573(1) A, β = 93.229(4)°, V= 1873.0 A 3 , Z= 4, R^F) = 0.044, wRnffF) = 0.135, T= 293 K. Source of material 2.0 mmol of sodium was dissolved in 30 ml of absolute ethanol and 2.0 mmol of 6-(2-fluorobenzoyl)-2-benzothiazolinone [1,2] was added to this solution. After 6-(2-fluorobenzoyl)-2benzothiazolinone had dissolved, the solution was stirred for one hour and then evaporated to dryness. The solid residue was dissolved in dimethylformamide and 2.0 mmol of ethyl 4-chlorobutanoate was added. The final solution was refluxed at 353 Κ for 4 h. The solution was cooled to 273 Κ and then 100 g of ice-water was added and stirring continued for 1 h between 273 Κ and 283 K. The precipitate thus formed was collected by filtration, washed with water, dried and crystallized from ether. Experimental details The ethyl group was found to be disordered and resolved into two positions whose site occupancies were refined isotropically to 0.616(7)/0.384. The Csp2—O, Cip3—Ο and C—C bond lengths of the involved atoms were restrained to 1.340(5) A, 1.450(5) A and 1.530(5) A, respectively. A split of 03 into two sites was omitted, the O-C-O angles are 122.6(4)° (04) and 121.8(4)° (04A). Discussion A comparison between the title structure and those of known thiazole derivatives [3-5] reveals no significant differences, either in bond lengths or in bond angles. Moreover, the derivatives of the tide compound show higher analgesic activity than aspirin and have an anti-inflammatory activity as good as Indometacin [5]. In the butanoate group of the title structure, the freelv refined C—C bond lengths range from 1.479(4) A to 1.526(4) A and the C-C-C bond angles are 110.6(2)° and 113.0(2)°. The CI—F distance 1.346(3) A is in agreement with those of other compounds, such as 5-chloro-6-(2-fluorobenzoyl)-l,3-benzoxazol-2(3i/)one [3] (1.356(2) A) and trans, cis-(±)-3'-(4-fluorophenyl)-2phenylspiro[2//-1 -benzothiopyran-3(4H),2' -oxiranj-4-one-1 oxide [4] (1.363(4) A). The bond distances of S—C14 and S—C12 are 1.787(3) A and 1.749(2) A , respectively. These values are in agreement with those in 3-(6-benzoyl-2-oxo-2,3dihydro-2-benzothiazol-3-yl)propanoic acid [5] (1.781(4) A and 1.743(4) A ) . The 01-C7-C8,01-C7-C6, F-C1-C6 and F C l C2 bond angles are 121.2(2)°, 119.7(2)°, 118.8(2)° and 118.0(2)°, respectively. The C3-C4-C5-C6 and 02-C14-N-C11 torsion angles are 0.0(5)° and 179.8(3)°, respectively, and the double bond length of C14=02 is 1.212(3) A. Table 1. Data collection and handling. Crystal: Wavelength: