Iso­propyl 2-bromo-4-(N-phthalimido)­butanoate

Molecules of the title compound, C₁₅H₁₆BrNO₄, are hydrogen bonded to form layers perpendicular to [100] and form enantiomeric pairs related by the c-glide (-x + ½, y, z - ½).

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.013 Å
• R factor = 0.073
• wR factor = 0.196
• Data-to-parameter ratio = 22.4

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes



ABSTM_02  When printed, the submitted absorption T values will be replaced
          by the scaled T values. Since the ratio of scaled T's is
          identical to the ratio of reported T values, the scaling does
          not imply a change to the absorption corrections used in the
          study.
          Ratio of Tmax expected/reported      0.836
          Tmax scaled      0.353 Tmin scaled      0.298

REFLT_03
         From the CIF: _diffrn_reflns_theta_max           31.05
         From the CIF: _reflns_number_total               4189
         Count of symmetry unique reflns         2660
         Completeness (_total/calc)            157.48%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured      1529
         Fraction of Friedel pairs measured     0.575
         Are heavy atom types Z>Si present          yes
          Please check that the estimate of the number of Friedel pairs is
          correct. If it is not, please give the correct count in the
          _publ_section_exptl_refinement section of the submitted CIF.

---

S1. Comment

The racemic title compound, (I), was required as an alkylating agent for oxaaza-macrocycles (Kuksa et al., 2000; Wardell & Lin, 1998).

The polar structure of (I) (Fig. 1) consists of alternating pairs of layers made up from one of the two enantiomers. Each layer is formed by one enantiomer linked via C11—H11···O3ⁱ hydrogen bonds [symmetry code: (i) x, y - 1, z]; thus, the layers form normal to [100] (Fig. 2). The distance between adjacent carbon rings within each layer is 3.294 (8) Å; hence, there is π–π bonding within the layers. In addition, there is an C9—H9···Br1 intramolecular hydrogen bond.

The layers form pairs between the two enantiomers where the enantiomers are related by the the symmetry operation (-x + 1/2, y, z - 1/2) (Fig. 3).

Examination of the structure with PLATON (Spek, 2000) showed that there were no solvent-accessible voids within the crystal lattice.

S2. Experimental

The title compound was prepared according to a published procedure (Kruper et al., 1993). Purification was achieved via column chromatogaphy on silica gel using chloroform as eluent with recrystallization from ethanol (m.p. 344–346 K; literature m.p. 345–347.5 K).

S3. Refinement

H atoms were placed in geometrical positions and refined using a riding model using the AFIX commands of SHELX.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEX in OSCAIL (McArdle, 1994, 2000) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CIFTAB (Sheldrick, 1997).

Figures

	Fig. 1. The asymmetric unit of the title compound with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probablity level.
	Fig. 2. Layers formed by hydrogen bonding of successive layers along b.
	Fig. 3. Relative orientation of layers within the unit cell, viewed normal to (010).

1-methylethyl 2-bromo-4-(N-phthalimido)butanoate

Crystal data

C15H16BrNO4	Dx = 1.480 Mg m^−3
Mr = 354.20	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pca21	Cell parameters from 2380 reflections
a = 27.307 (2) Å	θ = 2.2–25.8°
b = 4.6228 (4) Å	µ = 2.60 mm^−1
c = 12.5888 (11) Å	T = 296 K
V = 1589.2 (2) Å^3	Block, colourless
Z = 4	0.50 × 0.50 × 0.40 mm
F(000) = 720

Data collection

Bruker SMART 1000 area CCD detector diffractometer	4189 independent reflections
Radiation source: fine-focus sealed tube	2201 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.082
ϕ–ω scans	θmax = 31.1°, θmin = 1.5°
Absorption correction: multi-scan (SADABS: Bruker, 1999)	h = −31→39
Tmin = 0.356, Tmax = 0.423	k = −6→6
11746 measured reflections	l = −14→17

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.074	H-atom parameters constrained
wR(F^2) = 0.196	w = 1/[σ^2(Fo^2) + (0.0921P)^2 + 0.1679P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
4189 reflections	Δρmax = 0.70 e Å^−3
187 parameters	Δρmin = −0.91 e Å^−3
1 restraint	Absolute structure: (Flack, 1983)
Primary atom site location: heavy-atom method	Absolute structure parameter: 0.06 (2)

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4073 (3)	0.4301 (16)	0.8873 (4)	0.0444 (16)
C2	0.3888 (5)	0.341 (2)	0.9836 (8)	0.077 (3)
H2	0.3644	0.2010	0.9876	0.093*
C3	0.4078 (4)	0.467 (2)	1.0740 (7)	0.069 (3)
H3	0.3955	0.4115	1.1397	0.083*
C4	0.4442 (4)	0.673 (3)	1.0705 (7)	0.080 (3)
H4	0.4568	0.7483	1.1334	0.095*
C5	0.4623 (4)	0.768 (2)	0.9733 (7)	0.067 (3)
H5	0.4860	0.9123	0.9693	0.080*
C6	0.4435 (3)	0.6398 (14)	0.8831 (6)	0.0439 (18)
C7	0.4546 (3)	0.6942 (17)	0.7689 (6)	0.0440 (18)
O1	0.4820 (2)	0.8742 (12)	0.7298 (4)	0.0612 (16)
C8	0.3959 (3)	0.3480 (15)	0.7769 (6)	0.044 (2)
O2	0.3689 (2)	0.1466 (11)	0.7456 (4)	0.0644 (16)
N1	0.4251 (2)	0.5059 (13)	0.7104 (5)	0.0452 (14)
C9	0.4238 (3)	0.4853 (19)	0.5940 (5)	0.0508 (18)
H9A	0.4248	0.2838	0.5726	0.061*
H9B	0.4522	0.5819	0.5641	0.061*
C10	0.3771 (3)	0.6267 (15)	0.5529 (5)	0.0407 (16)
H10A	0.3491	0.5302	0.5842	0.049*
H10B	0.3765	0.8273	0.5755	0.049*
C11	0.3729 (3)	0.6141 (14)	0.4329 (5)	0.0421 (17)
H11	0.3709	0.4132	0.4085	0.051*
Br1	0.42793 (3)	0.81925 (18)	0.36266 (6)	0.0632 (3)
C12	0.3294 (3)	0.7847 (17)	0.3949 (6)	0.0485 (19)
O3	0.3117 (2)	0.9855 (14)	0.4376 (5)	0.0689 (17)
O4	0.3113 (2)	0.6718 (13)	0.3039 (5)	0.0646 (16)*
C13	0.2687 (4)	0.816 (2)	0.2576 (9)	0.085 (3)
H13	0.2696	1.0238	0.2730	0.102*
C14	0.2240 (4)	0.683 (3)	0.3032 (13)	0.132 (6)
H14A	0.2292	0.4791	0.3124	0.198*
H14B	0.1969	0.7136	0.2559	0.198*
H14C	0.2170	0.7701	0.3707	0.198*
C15	0.2731 (8)	0.764 (5)	0.1401 (13)	0.170 (8)
H15A	0.3023	0.8539	0.1139	0.254*
H15B	0.2451	0.8440	0.1046	0.254*
H15C	0.2745	0.5593	0.1268	0.254*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.066 (4)	0.047 (3)	0.019 (4)	0.002 (3)	0.001 (3)	0.004 (3)
C2	0.112 (9)	0.074 (6)	0.046 (5)	0.001 (6)	0.019 (6)	0.022 (5)
C3	0.104 (8)	0.077 (6)	0.026 (4)	0.018 (6)	0.011 (5)	0.000 (4)
C4	0.084 (7)	0.118 (9)	0.037 (4)	0.022 (7)	−0.005 (4)	−0.011 (6)
C5	0.088 (8)	0.091 (7)	0.021 (4)	−0.009 (6)	−0.015 (4)	−0.013 (4)
C6	0.047 (4)	0.044 (4)	0.041 (5)	0.006 (3)	0.001 (3)	0.003 (3)
C7	0.044 (4)	0.049 (4)	0.039 (4)	−0.003 (4)	0.001 (3)	0.024 (4)
O1	0.094 (5)	0.052 (3)	0.037 (3)	−0.011 (3)	0.001 (3)	0.005 (2)
C8	0.067 (5)	0.025 (3)	0.041 (4)	−0.008 (3)	0.010 (4)	0.006 (3)
O2	0.104 (5)	0.049 (3)	0.040 (3)	−0.019 (3)	0.011 (3)	−0.002 (3)
N1	0.056 (4)	0.053 (4)	0.027 (3)	−0.004 (3)	0.003 (3)	0.005 (3)
C9	0.064 (5)	0.066 (5)	0.022 (3)	−0.001 (4)	0.000 (3)	−0.003 (3)
C10	0.057 (4)	0.042 (4)	0.023 (3)	−0.001 (3)	0.001 (3)	0.000 (3)
C11	0.066 (5)	0.036 (4)	0.024 (3)	−0.010 (3)	0.000 (3)	−0.004 (3)
Br1	0.0657 (5)	0.0917 (5)	0.0322 (3)	−0.0122 (4)	0.0082 (5)	0.0038 (6)
C12	0.055 (5)	0.050 (4)	0.040 (4)	−0.016 (4)	−0.007 (3)	−0.001 (3)
O3	0.075 (4)	0.068 (4)	0.063 (4)	0.012 (3)	−0.008 (3)	−0.021 (3)
C13	0.097 (8)	0.077 (6)	0.082 (7)	0.033 (6)	−0.048 (6)	−0.022 (6)
C14	0.059 (7)	0.156 (12)	0.181 (17)	0.040 (8)	−0.018 (8)	−0.047 (11)
C15	0.202 (18)	0.24 (2)	0.068 (9)	0.039 (16)	−0.073 (11)	−0.010 (10)

Geometric parameters (Å, º)

C1—C2	1.376 (11)	C9—H9B	0.9700
C1—C6	1.384 (11)	C10—C11	1.516 (8)
C1—C8	1.474 (10)	C10—H10A	0.9700
C2—C3	1.380 (16)	C10—H10B	0.9700
C2—H2	0.9300	C11—C12	1.504 (11)
C3—C4	1.377 (15)	C11—Br1	1.985 (7)
C3—H3	0.9300	C11—H11	0.9800
C4—C5	1.391 (14)	C12—O3	1.176 (9)
C4—H4	0.9300	C12—O4	1.353 (8)
C5—C6	1.382 (11)	O4—C13	1.462 (11)
C5—H5	0.9300	C13—C14	1.482 (19)
C6—C7	1.491 (10)	C13—C15	1.504 (19)
C7—O1	1.223 (9)	C13—H13	0.9800
C7—N1	1.396 (11)	C14—H14A	0.9600
C8—O2	1.252 (10)	C14—H14B	0.9600
C8—N1	1.366 (9)	C14—H14C	0.9600
N1—C9	1.468 (9)	C15—H15A	0.9600
C9—C10	1.524 (10)	C15—H15B	0.9600
C9—H9A	0.9700	C15—H15C	0.9600
C2—C1—C6	120.4 (8)	C11—C10—H10A	109.1
C2—C1—C8	132.5 (8)	C9—C10—H10A	109.1
C6—C1—C8	107.1 (6)	C11—C10—H10B	109.1
C1—C2—C3	117.4 (11)	C9—C10—H10B	109.1
C1—C2—H2	121.3	H10A—C10—H10B	107.8
C3—C2—H2	121.3	C12—C11—C10	110.9 (6)
C4—C3—C2	122.5 (9)	C12—C11—Br1	101.9 (4)
C4—C3—H3	118.7	C10—C11—Br1	111.6 (5)
C2—C3—H3	118.7	C12—C11—H11	110.7
C3—C4—C5	120.2 (9)	C10—C11—H11	110.7
C3—C4—H4	119.9	Br1—C11—H11	110.7
C5—C4—H4	119.9	O3—C12—O4	122.8 (8)
C6—C5—C4	117.1 (10)	O3—C12—C11	126.4 (7)
C6—C5—H5	121.5	O4—C12—C11	110.8 (7)
C4—C5—H5	121.5	C12—O4—C13	116.8 (7)
C5—C6—C1	122.3 (7)	O4—C13—C14	108.2 (10)
C5—C6—C7	130.1 (7)	O4—C13—C15	104.8 (10)
C1—C6—C7	107.5 (6)	C14—C13—C15	112.2 (12)
O1—C7—N1	124.5 (7)	O4—C13—H13	110.5
O1—C7—C6	128.8 (8)	C14—C13—H13	110.5
N1—C7—C6	106.6 (6)	C15—C13—H13	110.5
O2—C8—N1	123.3 (7)	C13—C14—H14A	109.5
O2—C8—C1	127.7 (7)	C13—C14—H14B	109.5
N1—C8—C1	108.5 (6)	H14A—C14—H14B	109.5
C8—N1—C7	110.3 (6)	C13—C14—H14C	109.5
C8—N1—C9	124.2 (7)	H14A—C14—H14C	109.5
C7—N1—C9	125.4 (6)	H14B—C14—H14C	109.5
N1—C9—C10	109.3 (6)	C13—C15—H15A	109.5
N1—C9—H9A	109.8	C13—C15—H15B	109.5
C10—C9—H9A	109.8	H15A—C15—H15B	109.5
N1—C9—H9B	109.8	C13—C15—H15C	109.5
C10—C9—H9B	109.8	H15A—C15—H15C	109.5
H9A—C9—H9B	108.3	H15B—C15—H15C	109.5
C11—C10—C9	112.7 (6)
C6—C1—C2—C3	−0.3 (14)	C1—C8—N1—C7	−1.4 (9)
C8—C1—C2—C3	−179.3 (9)	O2—C8—N1—C9	8.1 (12)
C1—C2—C3—C4	−0.7 (15)	C1—C8—N1—C9	−179.4 (7)
C2—C3—C4—C5	2.1 (16)	O1—C7—N1—C8	−175.2 (8)
C3—C4—C5—C6	−2.5 (15)	C6—C7—N1—C8	1.9 (8)
C4—C5—C6—C1	1.5 (13)	O1—C7—N1—C9	2.7 (13)
C4—C5—C6—C7	179.4 (9)	C6—C7—N1—C9	179.8 (7)
C2—C1—C6—C5	−0.1 (13)	C8—N1—C9—C10	72.3 (9)
C8—C1—C6—C5	179.1 (8)	C7—N1—C9—C10	−105.3 (8)
C2—C1—C6—C7	−178.4 (8)	N1—C9—C10—C11	−179.9 (6)
C8—C1—C6—C7	0.8 (8)	C9—C10—C11—C12	−173.6 (6)
C5—C6—C7—O1	−2.8 (14)	C9—C10—C11—Br1	−60.7 (7)
C1—C6—C7—O1	175.3 (8)	C10—C11—C12—O3	27.7 (11)
C5—C6—C7—N1	−179.7 (9)	Br1—C11—C12—O3	−91.1 (8)
C1—C6—C7—N1	−1.7 (8)	C10—C11—C12—O4	−150.5 (6)
C2—C1—C8—O2	−8.5 (15)	Br1—C11—C12—O4	90.6 (5)
C6—C1—C8—O2	172.5 (8)	O3—C12—O4—C13	1.6 (12)
C2—C1—C8—N1	179.4 (10)	C11—C12—O4—C13	179.9 (8)
C6—C1—C8—N1	0.3 (9)	C12—O4—C13—C14	−89.4 (10)
O2—C8—N1—C7	−174.0 (8)	C12—O4—C13—C15	150.6 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9B···Br1	0.97	2.84	3.299 (7)	110
C11—H11···O3^i	0.98	2.58	3.353 (9)	136

Symmetry code: (i) x, y−1, z.