trans-(1R,3S)-Methyl 1-methyl-1,2,3,4-tetra­hydro-β-carboline-3-carboxyl­ate

The title compound, C₁₄H₁₆N₂O₂, was obtained from the reaction between S-tryptophan methyl ester hydro­chloride and acetaldehyde. The mol­ecule adopts a trans configuration, with the methyl and methoxy­carbonyl groups located on opposite sides of the central tetra­hydro-β-carboline unit. Bifurcated inter­molecular N—H...O/N hydrogen bonds link the mol­ecules into chains.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.036
• wR factor = 0.083
• Data-to-parameter ratio = 9.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT420_ALERT_2_C D-H Without Acceptor       N2     -   H2N    ...          ?

Alert level G
REFLT03_ALERT_4_G 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.
           From the CIF: _diffrn_reflns_theta_max           26.50
           From the CIF: _reflns_number_total               1468
           Count of symmetry unique reflns         1478
           Completeness (_total/calc)             99.32%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C9     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C11    = .          S

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 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
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: COLLECT (Nonius, 1999); cell refinement: DIRAX/LSQ (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: maXus (Mackay et al., 1999).

trans-(1R,3S)-Methyl 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylate

Crystal data

C14H16N2O2	F(000) = 520
Mr = 244.29	Dx = 1.325 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 108 reflections
a = 7.9948 (10) Å	θ = 4.2–20.4°
b = 9.6751 (10) Å	µ = 0.09 mm^−1
c = 15.8301 (8) Å	T = 299 K
V = 1224.5 (2) Å^3	Block, colourless
Z = 4	0.60 × 0.24 × 0.14 mm

Data collection

Bruker–Nonius KappaCCD diffractometer	Rint = 0.057
Radiation source: fine-focus sealed tube	θmax = 26.5°, θmin = 4.6°
φ and ω scans	h = −9→10
12651 measured reflections	k = −12→12
1468 independent reflections	l = −16→19
1274 reflections with I > 2σ(I)

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.036	w = 1/[σ^2(Fo^2) + (0.032P)^2 + 0.29P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.083	(Δ/σ)max < 0.001
S = 1.10	Δρmax = 0.16 e Å^−3
1468 reflections	Δρmin = −0.14 e Å^−3
164 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.028 (4)
Primary atom site location: structure-invariant direct methods

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	0.2020 (3)	0.8465 (2)	0.67345 (13)	0.0318 (5)
C2	0.0485 (3)	0.9071 (2)	0.69133 (15)	0.0401 (5)
H2	−0.0001	0.9704	0.6546	0.048*
C3	−0.0294 (3)	0.8695 (3)	0.76587 (17)	0.0464 (6)
H3	−0.1325	0.9080	0.7795	0.056*
C4	0.0436 (3)	0.7754 (2)	0.82104 (16)	0.0451 (6)
H4	−0.0112	0.7524	0.8709	0.054*
C5	0.1954 (3)	0.7159 (2)	0.80313 (13)	0.0382 (5)
H5	0.2430	0.6534	0.8407	0.046*
C6	0.2775 (3)	0.7494 (2)	0.72825 (13)	0.0307 (5)
C7	0.4307 (3)	0.7086 (2)	0.68895 (12)	0.0306 (5)
C8	0.4430 (3)	0.7798 (2)	0.61516 (13)	0.0300 (4)
C9	0.5800 (3)	0.7657 (2)	0.55160 (13)	0.0323 (5)
H9	0.5339	0.7164	0.5028	0.039*
C10	0.6463 (4)	0.9040 (2)	0.52016 (18)	0.0516 (7)
H10A	0.7334	0.8891	0.4795	0.077*
H10B	0.5564	0.9544	0.4944	0.077*
H10C	0.6898	0.9559	0.5670	0.077*
C11	0.6629 (3)	0.5634 (2)	0.63741 (13)	0.0346 (5)
H11	0.7646	0.5191	0.6588	0.041*
C12	0.5596 (3)	0.6049 (2)	0.71494 (13)	0.0373 (5)
H12A	0.6322	0.6444	0.7577	0.045*
H12B	0.5055	0.5240	0.7387	0.045*
C13	0.5799 (3)	0.4598 (2)	0.57946 (14)	0.0352 (5)
C14	0.3886 (4)	0.2776 (3)	0.56660 (17)	0.0548 (7)
H14A	0.3068	0.2296	0.5998	0.082*
H14B	0.3356	0.3179	0.5181	0.082*
H14C	0.4733	0.2139	0.5485	0.082*
N1	0.3064 (2)	0.86540 (18)	0.60559 (11)	0.0328 (4)
H1N	0.2829	0.9097	0.5558	0.039*
N2	0.7179 (2)	0.68128 (19)	0.58566 (11)	0.0365 (4)
H2N	0.7857	0.7371	0.6223	0.044*
O1	0.6167 (3)	0.44408 (17)	0.50668 (11)	0.0590 (6)
O2	0.4634 (2)	0.38400 (17)	0.61719 (10)	0.0445 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0323 (11)	0.0285 (10)	0.0346 (11)	0.0000 (10)	−0.0037 (9)	−0.0036 (9)
C2	0.0333 (12)	0.0372 (12)	0.0496 (13)	0.0048 (11)	−0.0045 (11)	−0.0016 (11)
C3	0.0307 (12)	0.0501 (14)	0.0585 (16)	0.0007 (12)	0.0063 (11)	−0.0063 (12)
C4	0.0416 (13)	0.0452 (13)	0.0486 (14)	−0.0064 (12)	0.0129 (11)	−0.0013 (11)
C5	0.0434 (13)	0.0339 (11)	0.0375 (11)	−0.0044 (11)	0.0012 (10)	0.0021 (10)
C6	0.0330 (11)	0.0277 (10)	0.0314 (10)	−0.0011 (9)	−0.0024 (9)	−0.0048 (9)
C7	0.0342 (11)	0.0299 (10)	0.0275 (10)	0.0037 (10)	−0.0034 (9)	−0.0022 (8)
C8	0.0317 (11)	0.0276 (10)	0.0308 (10)	0.0016 (10)	−0.0044 (9)	−0.0027 (8)
C9	0.0356 (11)	0.0301 (10)	0.0313 (10)	0.0005 (10)	−0.0002 (9)	−0.0017 (9)
C10	0.0558 (16)	0.0355 (13)	0.0635 (16)	−0.0025 (12)	0.0149 (14)	0.0055 (12)
C11	0.0336 (11)	0.0368 (12)	0.0333 (11)	0.0110 (10)	−0.0009 (9)	0.0025 (9)
C12	0.0445 (13)	0.0376 (11)	0.0298 (11)	0.0098 (11)	−0.0036 (10)	−0.0001 (9)
C13	0.0421 (13)	0.0281 (10)	0.0353 (12)	0.0097 (10)	0.0042 (10)	0.0048 (9)
C14	0.0601 (16)	0.0534 (15)	0.0508 (14)	−0.0121 (14)	0.0003 (13)	−0.0017 (13)
N1	0.0355 (9)	0.0316 (9)	0.0312 (9)	0.0054 (8)	−0.0030 (8)	0.0031 (7)
N2	0.0314 (9)	0.0373 (10)	0.0409 (10)	0.0012 (9)	−0.0020 (8)	−0.0013 (8)
O1	0.0951 (16)	0.0423 (10)	0.0397 (10)	−0.0170 (10)	0.0237 (10)	−0.0077 (8)
O2	0.0459 (9)	0.0508 (9)	0.0368 (8)	−0.0055 (9)	0.0041 (8)	−0.0009 (8)

Geometric parameters (Å, º)

C1—N1	1.372 (3)	C9—H9	0.980
C1—C2	1.389 (3)	C10—H10A	0.960
C1—C6	1.414 (3)	C10—H10B	0.960
C2—C3	1.383 (3)	C10—H10C	0.960
C2—H2	0.930	C11—N2	1.471 (3)
C3—C4	1.390 (3)	C11—C13	1.512 (3)
C3—H3	0.930	C11—C12	1.533 (3)
C4—C5	1.373 (3)	C11—H11	0.980
C4—H4	0.930	C12—H12A	0.970
C5—C6	1.393 (3)	C12—H12B	0.970
C5—H5	0.930	C13—O1	1.199 (3)
C6—C7	1.430 (3)	C13—O2	1.327 (3)
C7—C8	1.360 (3)	C14—O2	1.434 (3)
C7—C12	1.496 (3)	C14—H14A	0.960
C8—N1	1.379 (3)	C14—H14B	0.960
C8—C9	1.494 (3)	C14—H14C	0.960
C9—N2	1.474 (3)	N1—H1N	0.918
C9—C10	1.522 (3)	N2—H2N	0.961
N1—C1—C2	129.8 (2)	H10A—C10—H10B	109.5
N1—C1—C6	108.02 (18)	C9—C10—H10C	109.5
C2—C1—C6	122.2 (2)	H10A—C10—H10C	109.5
C3—C2—C1	117.4 (2)	H10B—C10—H10C	109.5
C3—C2—H2	121.3	N2—C11—C13	107.88 (17)
C1—C2—H2	121.3	N2—C11—C12	113.79 (17)
C2—C3—C4	121.3 (2)	C13—C11—C12	115.02 (19)
C2—C3—H3	119.4	N2—C11—H11	106.5
C4—C3—H3	119.3	C13—C11—H11	106.5
C5—C4—C3	121.1 (2)	C12—C11—H11	106.6
C5—C4—H4	119.4	C7—C12—C11	109.08 (17)
C3—C4—H4	119.5	C7—C12—H12A	109.9
C4—C5—C6	119.6 (2)	C11—C12—H12A	109.8
C4—C5—H5	120.2	C7—C12—H12B	109.9
C6—C5—H5	120.2	C11—C12—H12B	109.8
C5—C6—C1	118.4 (2)	H12A—C12—H12B	108.3
C5—C6—C7	135.2 (2)	O1—C13—O2	122.3 (2)
C1—C6—C7	106.40 (18)	O1—C13—C11	124.0 (2)
C8—C7—C6	107.19 (18)	O2—C13—C11	113.65 (18)
C8—C7—C12	121.76 (19)	O2—C14—H14A	109.0
C6—C7—C12	131.01 (19)	O2—C14—H14B	109.8
C7—C8—N1	109.96 (18)	H14A—C14—H14B	109.5
C7—C8—C9	125.81 (19)	O2—C14—H14C	109.5
N1—C8—C9	124.19 (17)	H14A—C14—H14C	109.5
N2—C9—C8	110.66 (17)	H14B—C14—H14C	109.5
N2—C9—C10	110.25 (19)	C1—N1—C8	108.40 (16)
C8—C9—C10	113.27 (18)	C1—N1—H1N	127.6
N2—C9—H9	107.5	C8—N1—H1N	122.5
C8—C9—H9	107.5	C11—N2—C9	114.20 (17)
C10—C9—H9	107.5	C11—N2—H2N	105.6
C9—C10—H10A	109.9	C9—N2—H2N	109.3
C9—C10—H10B	109.0	C13—O2—C14	115.96 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1^i	0.92	2.18	2.976 (2)	145
N1—H1N···N2^i	0.92	2.46	3.142 (2)	131

Symmetry code: (i) x−1/2, −y+3/2, −z+1.