Crystal structure of (S)-1-(1,3-benzo­thia­zol-2-yl)-2,2,2-tri­fluoro­ethanol

Svitlana V Shishkina; Olexandr V Kucher; Anastasiya O Kolodiazhnaya; Oleg B Smolii; Andrey A Tolmachev

doi:10.1107/S1600536814016547

. 2014 Aug 1;70(Pt 9):o946. doi: 10.1107/S1600536814016547

Crystal structure of (S)-1-(1,3-benzothiazol-2-yl)-2,2,2-trifluoroethanol

Svitlana V Shishkina ^a,^*, Olexandr V Kucher ^b, Anastasiya O Kolodiazhnaya ^b, Oleg B Smolii ^b, Andrey A Tolmachev ^c

PMCID: PMC4186080 PMID: 25309270

Abstract

In the title compound, C₉H₆F₃NOS, the 1,3-benzothiazole ring system is essentially planar, with an r.m.s. deviation of 0.006 Å. In the crystal, molecules are linked via O—H⋯N hydrogen bonds, forming zigzag chains along [010].

Keywords: crystal structure; 1,3-benzothiazole; 2,2,2-trifluoroethanol; hydrogen bonding

Related literature

For the synthesis of 1-substituted 2,2,2-trifluoroethanols from ketones, see: Yamazaki et al. (1993 ▶). For the enzymatic kinetic resolution of 1-substituted 2,2,2-trifluoroethanols, see: Omote et al. (2001 ▶); Xu et al. (2009 ▶). For the utilization of cinchonidine as a chiral solvating reagent, see: Kolodyazhnyi et al. (2006 ▶).

Experimental

Crystal data

C₉H₆F₃NOS
M _r = 233.21
Monoclinic,
a = 9.2116 (9) Å
b = 5.5052 (4) Å
c = 10.2279 (8) Å
β = 107.411 (9)°
V = 494.91 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.34 mm⁻¹
T = 293 K
0.20 × 0.05 × 0.05 mm

Data collection

Agilent Xcalibur3 diffractometer
Absorption correction: multi-scan (CrysAlis RED; Agilent, 2012 ▶) T _min = 0.935, T _max = 0.983
4650 measured reflections
2768 independent reflections
2293 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.108
S = 1.12
2768 reflections
160 parameters
4 restraints
All H-atom parameters refined
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.20 e Å⁻³
Absolute structure: Flack (1983 ▶), 1199 Friedel pairs
Absolute structure parameter: −0.03 (9)

Data collection: CrysAlis CCD (Agilent, 2012 ▶); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Agilent, 2012 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536814016547/lh5717sup1.cif

e-70-0o946-sup1.cif^{(18.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814016547/lh5717Isup2.hkl

e-70-0o946-Isup2.hkl^{(135.9KB, hkl)}

Click here for additional data file.^{(3.8KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814016547/lh5717Isup3.cml

Click here for additional data file.^{(1.2MB, tif)}

. DOI: 10.1107/S1600536814016547/lh5717fig1.tif

The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.

Click here for additional data file.^{(346.7KB, tif)}

. DOI: 10.1107/S1600536814016547/lh5717fig2.tif

Part of the crystal structure with hydrogen bonds shown by dashed lines. Only H atoms involved in H-bonds are shown.

CCDC reference: 1014380

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O⋯N1ⁱ	0.84 (4)	1.96 (4)	2.781 (2)	166 (4)

Open in a new tab

Symmetry code: (i) Inline graphic .

supplementary crystallographic information

S1. Comment

2,2,2-Trifluoro-1-substituted ethanols attract attention as building blocks for introducing a chiral CF₃-containing motif into biologically active molecules and mimicking carboxylic groups. Among them, 2,2,2-trifluoro-1-heteroaryl ethanols, promising synthetic targets, have been poorly explored because of a lack of suitable procedures for obtaining the enantipure compounds from racemates. We have recently proposed a convenient procedure for enzyme-catalyzed kinetic resolution of racemic 2,2,2-trifluoro-1-heteroaryl ethanols on a series of 14 compounds. Herein, we report the crystal structure of (S)-1-(benzo[d]thiazol-2-yl)-2,2,2-trifluoroethanol (I) (Fig. 1). The non-centrosymmetric space group clearly confirms the presence of one enantiomer in the crystal. The absolute configuration of the chiral center at atom C8 (S-configuration) is determined using the value of the Flack parameter (-0.03 (9)). The substituent on the bicyclic fragment is oriented in such way that the hydroxyl group has a conformation intermediate between sp- and -sc- relative to the N1—C7 endocyclic bond (the N1—C7—C8—O1 torsion angle is -30.8 (3) °). The trifluoromethyl group is oriented in such way that the C9—F2 bond is anti-periplanar to the C7—C8 bond (the N1—C7—C8—C9 and C7—C8—C9—F2 torsion angles are 88.5 (3) ° and 177.3 (2) °, respectively). In the crystal, molecules are linked via O—H···N hydrogen bonds (Fig. 2) forming zigzag chains along [0 1 0].

S2. Experimental

Synthesis ofrac-1-(benzo[d]thiazol-2-yl)-2,2,2-trifluoroethanol: To a solution of 1-(benzo[d]thiazol-2-yl)-2,2,2-trifluoroethanone (115.5 g, 0.5 mol) in methanol (500 ml) sodium borohydride (18.9 g, 0.5 mol) was added in small portions, maintaining the temperature of the reaction mixture below 303K. The mixture was stirred at room temperature until completion of the reaction (monitored by TLC). The solvent was removed under reduced pressure; to the crude was added 200 ml of water and the aqueous solution was extracted with dichloromethane (3 × 150 ml). The organic phase was dried over Na₂SO₄ and evaporated yield the desired product. Yield: 114.2 g, 98%; white solid; m.p.: 377 K; ¹H NMR (400 MHz, CDCl₃): δ_H = 5.19 (qd, 1H, ³J_F,H = 7 Hz, ³J_H,H = 7 Hz, CH), 6.98–7.08 (m, 2H, PhH), 7.48 (d, 1H, ³J_H,H = 7 Hz, OH), 7.56 (d, 1H, ³J_H,H = 7.6 Hz, PhH), 7.66 (d, 1H, ³J_H,H = 8 Hz, PhH); ¹³C NMR (125 MHz, APT, CDCl₃): δ_C = 69.4 (q, ²J_F,_C = 32 Hz, CH), 122.4 (PhH), 123.1 (PhH), 123.7 (q, ¹J_F,_C = 282 Hz, CF₃), 125.7 (PhH), 126.4 (PhH), 134.4 (C Ar), 152.7 (C Ar), 167.7 (C Ar); MS (APCI) m/z calculated for C₉H₇F₃NOS 234.0 [M+H]⁺, found 234.0.

Kinetic resolution ofrac-1-(benzo[d]thiazol-2-yl)-2,2,2-trifluoroethanol with vinyl acetate andBurkholderia cepacia lipase: The racemic alcohol (11.4 g, 0.05 mol) and vinyl acetate (14.3 ml, 0.15 mol) were dissolved in TBME (250 ml) following by addition of Burkholderia cepacia lipase (6 g). The obtained mixture was incubated at 323 K, the progress of the reaction was monitored by the cinchonidine method (Kolodyazhnyi et al., 2006). Then, the enzyme was filtered off, washed with TBME and the combined TBME fractions were evaporated. The unacylated (S)-alcohol was separated from the (R)-ester by column chromatography (SiO₂, eluent: AcOEt/hexanes gradually changed from 1:20 to 1:1 (v/v)). The white needle-like crystals of the (S)-alcohol were formed after 1 week upon crystallization from chloroform.