Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680504050X/is6162sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053680504050X/is6162Isup2.hkl |
CCDC reference: 296589
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.039
- wR factor = 0.100
- Data-to-parameter ratio = 19.5
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature . 293 K PLAT322_ALERT_2_C Check Hybridisation of S1 in Main Residue . ? PLAT420_ALERT_2_C D-H Without Acceptor N2 - H3 ... ?
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion
To a solution of thiourea (0.76 g, 10 mmol) in absolute ethanol (50 ml), a solution of 3-(2-chloro-1-oxoethyl)-1-methyl-1-p-xylylcyclobutane (2.50 g, 10 mmol) in absolute ethanol (20 ml) was added dropwise at 323–327 K with continuous stirring. By monitoring the IR frequency of the carbonyl group of 3-(2-chloro-1-oxoethyl)-1-methyl-1-p-xylylcyclobutane, completion of the reaction was easily seen. After cooling to room temperature, the solution was made alkaline with an aqueous solution of NH3 (5%) to separate dark-green crystals of (I) from the reaction mixture. The precipitate was filtered off, washed with an aqueous ammonia solution and water several times, dried in air and recrystallized from water–ethanol (1:4) by slow evaporation (yield 76%; m.p. 407.5 K). Characteristic 1H NMR shifts (CDCl3, p.p.m.) are at 1.54 (s, 3H, –CH3 on cyclobutane), 2.22 (s, 3H, o-CH3 of p-xylyl), 2.33 (s, 3H, m-CH3 of p-xylyl), 2.48 (m, 2H, –CH2–), 2.59 (m, 2H, –CH2–), 3.43 (q, J = 9.2, 1H, >CH–), 5.55 (brs, 2H, NH2), 5.96 (s, 1H, aromatic in thiazole ring), 6.89 (s, 1H, aromatic), 7.03 (m, 2H, aromatic). Characteristic 13C NMR shifts (CDCl3, p.p.m.) are at 169.18, 155.84, 149.80, 135.57, 132.12, 131.43, 127.11, 126.85, 100.39, 41.89, 39.46, 31.09, 28.05, 21.29 and 19.71.
All H atoms, except for H1 and H3, were placed in calculated positions, with C—H distances in the range of 0.93–0.96 Å. Uiso(H) values were constrained to be 1.2 and 1.5 times Ueq of the carrier atom. Atoms H1 and H3 were located in a difference map and refined freely.
Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
C16H20N2S | Dx = 1.198 Mg m−3 |
Mr = 272.40 | Mo Kα radiation, λ = 0.71073 Å |
Trigonal, R3 | Cell parameters from 37485 reflections |
Hall symbol: -R 3 | θ = 1.6–28.0° |
a = 20.7083 (11) Å | µ = 0.20 mm−1 |
c = 18.2954 (10) Å | T = 293 K |
V = 6794.6 (6) Å3 | Prism, pale yellow |
Z = 18 | 0.57 × 0.48 × 0.38 mm |
F(000) = 2628 |
Stoe IPDS-2 diffractometer | 3557 independent reflections |
Radiation source: fine-focus sealed tube | 2851 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.068 |
Detector resolution: 6.67 pixels mm-1 | θmax = 27.8°, θmin = 2.0° |
ω scans | h = −26→27 |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | k = −27→27 |
Tmin = 0.900, Tmax = 0.944 | l = −23→23 |
37485 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0456P)2 + 3.0488P] where P = (Fo2 + 2Fc2)/3 |
3557 reflections | (Δ/σ)max = 0.001 |
182 parameters | Δρmax = 0.16 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C16H20N2S | Z = 18 |
Mr = 272.40 | Mo Kα radiation |
Trigonal, R3 | µ = 0.20 mm−1 |
a = 20.7083 (11) Å | T = 293 K |
c = 18.2954 (10) Å | 0.57 × 0.48 × 0.38 mm |
V = 6794.6 (6) Å3 |
Stoe IPDS-2 diffractometer | 3557 independent reflections |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | 2851 reflections with I > 2σ(I) |
Tmin = 0.900, Tmax = 0.944 | Rint = 0.068 |
37485 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.16 e Å−3 |
3557 reflections | Δρmin = −0.24 e Å−3 |
182 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.25932 (2) | 0.54840 (2) | 0.33641 (2) | 0.05501 (13) | |
N1 | 0.17396 (6) | 0.41911 (6) | 0.28044 (6) | 0.0447 (3) | |
N2 | 0.21589 (9) | 0.41453 (9) | 0.39814 (8) | 0.0614 (4) | |
H1 | 0.1990 (10) | 0.3649 (12) | 0.3946 (10) | 0.070 (5)* | |
H3 | 0.2467 (12) | 0.4374 (12) | 0.4310 (12) | 0.080 (6)* | |
C1 | 0.21259 (7) | 0.45130 (7) | 0.33876 (7) | 0.0444 (3) | |
C2 | 0.22109 (8) | 0.54313 (8) | 0.25131 (8) | 0.0505 (3) | |
H2 | 0.2290 | 0.5841 | 0.2236 | 0.061* | |
C3 | 0.17828 (7) | 0.47172 (7) | 0.23059 (7) | 0.0433 (3) | |
C4 | 0.13665 (8) | 0.44482 (8) | 0.16036 (8) | 0.0496 (3) | |
H4 | 0.1412 | 0.4866 | 0.1311 | 0.060* | |
C5 | 0.05451 (8) | 0.38134 (8) | 0.16455 (8) | 0.0504 (3) | |
H5A | 0.0189 | 0.3972 | 0.1528 | 0.061* | |
H5B | 0.0418 | 0.3541 | 0.2103 | 0.061* | |
C6 | 0.15330 (9) | 0.39285 (9) | 0.11371 (8) | 0.0542 (4) | |
H6A | 0.1767 | 0.3698 | 0.1409 | 0.065* | |
H6B | 0.1809 | 0.4160 | 0.0694 | 0.065* | |
C7 | 0.06843 (8) | 0.34025 (8) | 0.10087 (7) | 0.0487 (3) | |
C8 | 0.04145 (12) | 0.35473 (11) | 0.02801 (9) | 0.0763 (5) | |
H8A | 0.0612 | 0.4073 | 0.0219 | 0.114* | |
H8B | −0.0120 | 0.3297 | 0.0278 | 0.114* | |
H8C | 0.0583 | 0.3362 | −0.0113 | 0.114* | |
C9 | 0.03804 (8) | 0.25747 (8) | 0.11130 (7) | 0.0485 (3) | |
C10 | 0.07154 (11) | 0.21950 (10) | 0.08047 (9) | 0.0639 (4) | |
C11 | 0.03975 (15) | 0.14373 (12) | 0.09615 (12) | 0.0825 (6) | |
H11 | 0.0615 | 0.1177 | 0.0766 | 0.099* | |
C12 | −0.02204 (14) | 0.10614 (11) | 0.13904 (13) | 0.0847 (7) | |
H12 | −0.0404 | 0.0559 | 0.1491 | 0.102* | |
C13 | −0.05775 (11) | 0.14182 (9) | 0.16776 (11) | 0.0703 (5) | |
C14 | −0.02614 (9) | 0.21744 (8) | 0.15293 (8) | 0.0547 (4) | |
H14 | −0.0491 | 0.2426 | 0.1718 | 0.066* | |
C15 | −0.12730 (14) | 0.10161 (13) | 0.21371 (16) | 0.1077 (9) | |
H15A | −0.1600 | 0.0535 | 0.1928 | 0.162* | |
H15B | −0.1522 | 0.1302 | 0.2152 | 0.162* | |
H15C | −0.1140 | 0.0955 | 0.2625 | 0.162* | |
C16 | 0.13958 (15) | 0.25620 (15) | 0.03211 (12) | 0.0963 (7) | |
H16A | 0.1336 | 0.2869 | −0.0035 | 0.144* | |
H16B | 0.1457 | 0.2186 | 0.0076 | 0.144* | |
H16C | 0.1828 | 0.2865 | 0.0614 | 0.144* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0562 (2) | 0.04338 (19) | 0.0560 (2) | 0.01788 (16) | −0.00695 (16) | −0.00782 (15) |
N1 | 0.0511 (6) | 0.0408 (6) | 0.0414 (6) | 0.0224 (5) | −0.0048 (5) | 0.0006 (4) |
N2 | 0.0799 (10) | 0.0547 (8) | 0.0478 (7) | 0.0322 (7) | −0.0201 (7) | −0.0042 (6) |
C1 | 0.0459 (7) | 0.0459 (7) | 0.0437 (7) | 0.0246 (6) | −0.0030 (5) | −0.0033 (5) |
C2 | 0.0553 (8) | 0.0406 (7) | 0.0528 (8) | 0.0219 (6) | 0.0010 (6) | 0.0030 (6) |
C3 | 0.0458 (7) | 0.0406 (6) | 0.0441 (7) | 0.0222 (6) | 0.0010 (5) | 0.0033 (5) |
C4 | 0.0592 (8) | 0.0432 (7) | 0.0451 (7) | 0.0246 (6) | −0.0062 (6) | 0.0045 (5) |
C5 | 0.0511 (8) | 0.0500 (7) | 0.0557 (8) | 0.0293 (6) | −0.0088 (6) | −0.0044 (6) |
C6 | 0.0560 (8) | 0.0598 (9) | 0.0404 (7) | 0.0241 (7) | 0.0026 (6) | −0.0008 (6) |
C7 | 0.0577 (8) | 0.0501 (7) | 0.0389 (7) | 0.0274 (6) | −0.0089 (6) | 0.0000 (5) |
C8 | 0.1013 (14) | 0.0712 (11) | 0.0536 (10) | 0.0411 (11) | −0.0256 (9) | 0.0046 (8) |
C9 | 0.0586 (8) | 0.0514 (7) | 0.0398 (7) | 0.0306 (7) | −0.0160 (6) | −0.0068 (6) |
C10 | 0.0848 (12) | 0.0707 (10) | 0.0504 (9) | 0.0496 (9) | −0.0186 (8) | −0.0175 (7) |
C11 | 0.1182 (18) | 0.0758 (12) | 0.0792 (13) | 0.0677 (13) | −0.0335 (13) | −0.0260 (11) |
C12 | 0.1106 (17) | 0.0489 (9) | 0.0940 (15) | 0.0394 (11) | −0.0410 (13) | −0.0104 (10) |
C13 | 0.0725 (11) | 0.0512 (9) | 0.0754 (11) | 0.0220 (8) | −0.0273 (9) | 0.0033 (8) |
C14 | 0.0576 (8) | 0.0502 (8) | 0.0567 (9) | 0.0272 (7) | −0.0173 (7) | −0.0025 (6) |
C15 | 0.0876 (15) | 0.0721 (13) | 0.132 (2) | 0.0160 (12) | −0.0090 (14) | 0.0310 (14) |
C16 | 0.1172 (18) | 0.1190 (18) | 0.0745 (13) | 0.0753 (16) | 0.0091 (12) | −0.0251 (13) |
S1—C2 | 1.7251 (16) | C8—H8A | 0.9600 |
S1—C1 | 1.7424 (14) | C8—H8B | 0.9600 |
N1—C1 | 1.2998 (17) | C8—H8C | 0.9600 |
N1—C3 | 1.3890 (16) | C9—C14 | 1.390 (2) |
N2—C1 | 1.3478 (19) | C9—C10 | 1.401 (2) |
N2—H1 | 0.91 (2) | C10—C11 | 1.395 (3) |
N2—H3 | 0.83 (2) | C10—C16 | 1.508 (3) |
C2—C3 | 1.3436 (19) | C11—C12 | 1.365 (3) |
C2—H2 | 0.9300 | C11—H11 | 0.9300 |
C3—C4 | 1.4914 (19) | C12—C13 | 1.384 (3) |
C4—C6 | 1.542 (2) | C12—H12 | 0.9300 |
C4—C5 | 1.546 (2) | C13—C14 | 1.389 (2) |
C4—H4 | 0.9800 | C13—C15 | 1.508 (3) |
C5—C7 | 1.552 (2) | C14—H14 | 0.9300 |
C5—H5A | 0.9700 | C15—H15A | 0.9600 |
C5—H5B | 0.9700 | C15—H15B | 0.9600 |
C6—C7 | 1.554 (2) | C15—H15C | 0.9600 |
C6—H6A | 0.9700 | C16—H16A | 0.9600 |
C6—H6B | 0.9700 | C16—H16B | 0.9600 |
C7—C9 | 1.514 (2) | C16—H16C | 0.9600 |
C7—C8 | 1.532 (2) | ||
C2—S1—C1 | 88.67 (7) | C5—C7—C6 | 87.55 (10) |
C1—N1—C3 | 110.80 (11) | C7—C8—H8A | 109.5 |
C1—N2—H1 | 118.8 (12) | C7—C8—H8B | 109.5 |
C1—N2—H3 | 120.2 (15) | H8A—C8—H8B | 109.5 |
H1—N2—H3 | 116.6 (19) | C7—C8—H8C | 109.5 |
N1—C1—N2 | 124.34 (13) | H8A—C8—H8C | 109.5 |
N1—C1—S1 | 114.56 (10) | H8B—C8—H8C | 109.5 |
N2—C1—S1 | 121.07 (11) | C14—C9—C10 | 118.69 (15) |
C3—C2—S1 | 110.72 (11) | C14—C9—C7 | 118.46 (13) |
C3—C2—H2 | 124.6 | C10—C9—C7 | 122.84 (15) |
S1—C2—H2 | 124.6 | C11—C10—C9 | 117.44 (18) |
C2—C3—N1 | 115.23 (12) | C11—C10—C16 | 118.96 (18) |
C2—C3—C4 | 126.46 (12) | C9—C10—C16 | 123.60 (17) |
N1—C3—C4 | 118.31 (11) | C12—C11—C10 | 122.72 (19) |
C3—C4—C6 | 116.64 (12) | C12—C11—H11 | 118.6 |
C3—C4—C5 | 117.36 (12) | C10—C11—H11 | 118.6 |
C6—C4—C5 | 88.22 (11) | C11—C12—C13 | 120.83 (18) |
C3—C4—H4 | 110.9 | C11—C12—H12 | 119.6 |
C6—C4—H4 | 110.9 | C13—C12—H12 | 119.6 |
C5—C4—H4 | 110.9 | C12—C13—C14 | 116.84 (19) |
C4—C5—C7 | 90.11 (11) | C12—C13—C15 | 122.30 (19) |
C4—C5—H5A | 113.6 | C14—C13—C15 | 120.9 (2) |
C7—C5—H5A | 113.6 | C13—C14—C9 | 123.39 (16) |
C4—C5—H5B | 113.6 | C13—C14—H14 | 118.3 |
C7—C5—H5B | 113.6 | C9—C14—H14 | 118.3 |
H5A—C5—H5B | 110.9 | C13—C15—H15A | 109.5 |
C4—C6—C7 | 90.21 (11) | C13—C15—H15B | 109.5 |
C4—C6—H6A | 113.6 | H15A—C15—H15B | 109.5 |
C7—C6—H6A | 113.6 | C13—C15—H15C | 109.5 |
C4—C6—H6B | 113.6 | H15A—C15—H15C | 109.5 |
C7—C6—H6B | 113.6 | H15B—C15—H15C | 109.5 |
H6A—C6—H6B | 110.9 | C10—C16—H16A | 109.5 |
C9—C7—C8 | 110.21 (12) | C10—C16—H16B | 109.5 |
C9—C7—C5 | 116.10 (12) | H16A—C16—H16B | 109.5 |
C8—C7—C5 | 111.09 (13) | C10—C16—H16C | 109.5 |
C9—C7—C6 | 117.31 (12) | H16A—C16—H16C | 109.5 |
C8—C7—C6 | 112.93 (14) | H16B—C16—H16C | 109.5 |
C3—N1—C1—N2 | 176.49 (14) | C4—C6—C7—C8 | 97.03 (14) |
C3—N1—C1—S1 | −1.65 (15) | C4—C6—C7—C5 | −14.86 (11) |
C2—S1—C1—N1 | 1.46 (12) | C8—C7—C9—C14 | −96.63 (16) |
C2—S1—C1—N2 | −176.75 (13) | C5—C7—C9—C14 | 30.77 (17) |
C1—S1—C2—C3 | −0.81 (12) | C6—C7—C9—C14 | 132.27 (14) |
S1—C2—C3—N1 | 0.08 (16) | C8—C7—C9—C10 | 82.97 (18) |
S1—C2—C3—C4 | −179.38 (12) | C5—C7—C9—C10 | −149.63 (13) |
C1—N1—C3—C2 | 1.01 (17) | C6—C7—C9—C10 | −48.13 (18) |
C1—N1—C3—C4 | −179.48 (12) | C14—C9—C10—C11 | −2.6 (2) |
C2—C3—C4—C6 | 124.11 (15) | C7—C9—C10—C11 | 177.81 (14) |
N1—C3—C4—C6 | −55.34 (17) | C14—C9—C10—C16 | 177.71 (16) |
C2—C3—C4—C5 | −133.16 (15) | C7—C9—C10—C16 | −1.9 (2) |
N1—C3—C4—C5 | 47.39 (18) | C9—C10—C11—C12 | 0.7 (3) |
C3—C4—C5—C7 | −134.21 (12) | C16—C10—C11—C12 | −179.61 (19) |
C6—C4—C5—C7 | −14.93 (11) | C10—C11—C12—C13 | 1.8 (3) |
C3—C4—C6—C7 | 134.83 (12) | C11—C12—C13—C14 | −2.2 (3) |
C5—C4—C6—C7 | 14.91 (11) | C11—C12—C13—C15 | 178.4 (2) |
C4—C5—C7—C9 | 134.18 (12) | C12—C13—C14—C9 | 0.2 (2) |
C4—C5—C7—C8 | −98.86 (14) | C15—C13—C14—C9 | 179.65 (17) |
C4—C5—C7—C6 | 14.82 (11) | C10—C9—C14—C13 | 2.2 (2) |
C4—C6—C7—C9 | −133.13 (12) | C7—C9—C14—C13 | −178.17 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H1···N1i | 0.91 (2) | 2.15 (2) | 3.0540 (19) | 180 (2) |
N2—H3···Cg1i | 0.83 (2) | 2.453 (3) | 3.307 (2) | 167 (2) |
Symmetry code: (i) −x+1/3, −y+2/3, −z+2/3. |
Experimental details
Crystal data | |
Chemical formula | C16H20N2S |
Mr | 272.40 |
Crystal system, space group | Trigonal, R3 |
Temperature (K) | 293 |
a, c (Å) | 20.7083 (11), 18.2954 (10) |
V (Å3) | 6794.6 (6) |
Z | 18 |
Radiation type | Mo Kα |
µ (mm−1) | 0.20 |
Crystal size (mm) | 0.57 × 0.48 × 0.38 |
Data collection | |
Diffractometer | Stoe IPDS2 diffractometer |
Absorption correction | Integration (X-RED32; Stoe & Cie, 2002) |
Tmin, Tmax | 0.900, 0.944 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 37485, 3557, 2851 |
Rint | 0.068 |
(sin θ/λ)max (Å−1) | 0.656 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.100, 1.05 |
No. of reflections | 3557 |
No. of parameters | 182 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.16, −0.24 |
Computer programs: X-AREA (Stoe & Cie, 2002), X-AREA, X-RED (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
S1—C2 | 1.7251 (16) | N1—C3 | 1.3890 (16) |
S1—C1 | 1.7424 (14) | C2—C3 | 1.3436 (19) |
N1—C1 | 1.2998 (17) | C3—C4 | 1.4914 (19) |
N1—C1—N2 | 124.34 (13) | C3—C4—C5 | 117.36 (12) |
N1—C1—S1 | 114.56 (10) | C9—C7—C5 | 116.10 (12) |
C2—C3—C4—C6 | 124.11 (15) | C2—C3—C4—C5 | −133.16 (15) |
N1—C3—C4—C6 | −55.34 (17) | N1—C3—C4—C5 | 47.39 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H1···N1i | 0.91 (2) | 2.15 (2) | 3.0540 (19) | 180 (2) |
N2—H3···Cg1i | 0.83 (2) | 2.453 (3) | 3.307 (2) | 167 (2) |
Symmetry code: (i) −x+1/3, −y+2/3, −z+2/3. |
Various thiazole derivatives show herbicidal, anti-imflammatory, antimicrobial and antiparasitic activity (Koparir et al., 2004; Ahmedzade et al., 2003), and also liquid crystal properties (Coghi et al., 1976). Aminothiazoles have been extensively studied for a range of biological and industrial applications (Lynch et al., 1999; Toplak et al., 2003). 2-Amino-1,3-thiazole, the structure of which was reported by Caranoni & Reboul (1982), is itself listed as a thyroid inhibitor (Merck, 2001).
The title compound, (I), consists of aminothiazole, cyclobutane and benzene rings in the asymmetric unit (Fig. 1). The dihedral angle between the thiazole and benzene rings is 81.88 (9)°, comparable to 87.21 (2)° and 89.70 (2)° reported for 3-butyl-4-(3-methyl-3-phenylcyclobutyl)-1,3-thiazole-2(3H)-thione (Kirilmiş et al., 2005a) and 3-cyclohexl-4-(3-methyl-3-phenylcyclobutyl)-1,3-thiazole-2(3H)-thione (Kirilmiş et al., 2005b), respectively. The cyclobutane ring is puckered; the C5/C4/C6 plane forms a dihedral angle of 20.8 (2)° with the C6/C7/C5 plane. This compares well with the values of 24.37°, 23.82 (3)° and 23.5 (4)° reported for the above-mentioned compounds (Kirilmiş et al., 2005a,b) and hexafluorocyclobutane (Swenson et al., 1997), respectively. An intermolecular N2—H1···N1i hydrogen bond (symmetry code as Table 2) links the molecules, forming a hydrogen-bonded dimer of graph-set motif R22(8) (Fig. 2). Of greater interest is an intermolecular N—H···π interaction between the amino group and the benzene ring in the dimer (Table 2). As a result of these interactions, as well as van der Waals interactions, the molecules afford hexagonal cavities of diameter 3.774 Å along the c axis (Fig. 3).