organic papers
Acta Crystallographica Section E
Structure Reports
5-(N,N-Dimethylammoniomethyl)-2,2-dimethyl-
Online 4-oxido-6-oxo-6H-1,3-dioxine
ISSN 1600-5368
Jing-Hua Li,* Jin-Huan He and The title compound, C9H15NO4, a Mannich base of Meldrum’s Received 26 May 2005
acid, proves to be an inner salt. Accepted 24 August 2005
Zhi-Min Jin Online 31 August 2005
College of Pharmaceutical Sciences, Zhejiang
University of Technology, Hangzhou 310014, Comment
People’s Republic of China
Meldrum’s acid and its 5-monosubstituted derivatives are
Correspondence e-mail: lijh@zjut.edu.cn
versatile reagents with much stronger acidity than their
corresponding acyclic malonates (McNab, 1978; Pihlaja &
Seilo, 1968, 1969). According to our previous work (Li &
Chen, 2000; Li et al., 2001), there are also obvious differences
Key indicators
between the aminomethyl derivatives, i.e. (I), the title
Single-crystal X-ray study compound, and (II), in their chemical and physical properties.
T = 293 K
Mean (C–C) = 0.002 Å
R factor = 0.039
wR factor = 0.102
Data-to-parameter ratio = 9.5
For details of how these key indicators were
automatically derived from the article, see
http://journals.iucr.org/e.
As described in our previous work (Li & Chen, 2000), (II) is
soluble in polar organic solvents and can readily condense
with some reactive methyl ketones. On the other hand, (I) is
insoluble in most polar organic solvents but soluble in water.
The IR spectrum of (I) exhibits a conjugated carbonyl
absorption at 1680 cm1 [1770 and 1730 cm1 for (II)], and the
1
H NMR spectrum of (I) exhibits only one single peak at
1.64 p.p.m. for the two methyl groups on the dioxane ring [two
single peaks at 0.9 and 1.7 p.p.m. for (II)]. Unlike (II), (I) is of
low reactivity. All of these factors imply that (I) might be an
inner salt (Li & Chen, 2000). In order to confirm this deduc-
tion, we examined (I) by X-ray structural analysis. The result
shows that (I) is an inner salt. In the structure, the H atom
originally attached to atom O3 is transferred to atom N1, and
an N—H O intramolecular hydrogen bond is formed (Fig. 1
Figure 1
# 2005 International Union of Crystallography The molecular structure of (I) with the atom numbering, showing
Printed in Great Britain – all rights reserved displacement ellipsoids at the 30% probability level.
o3106 Li et al. C9H15NO4 doi:10.1107/S1600536805026826 Acta Cryst. (2005). E61, o3106–o3107
organic papers
and Table 2). There is also an intermolecular hydrogen bond, Table 1
which is stronger (Table 2). Selected geometric parameters (Å, ).
O3—C5 1.2503 (16) C6—C4 1.423 (2)
O4—C4 1.2196 (18) C6—C5 1.3952 (19)
Experimental
(Me2N)2CH2 (10 mmol) was added slowly to a stirred acetonitrile C4—C6—C7 121.08 (12) O3—C5—C6 124.68 (12)
C5—C6—C4 120.87 (12) O4—C4—C6 127.02 (13)
solution (20 ml) of Meldrum’s acid (10 mmol) and acetic anhydride C5—C6—C7 117.43 (12)
(11 mmol) with cooling. The mixture was stirred at room temperature
for 30 min to complete the reaction. The precipitated crystals were
collected, washed with acetonitrile and then recrystallized from
water–acetone (1:1 v/v) to give single crystals with a yield of 95% Table 2
(m.p. 433–434 K). IR (KBr, cm1): 2550, 1680, 1605, 1410, 1380, 1210. Hydrogen-bond geometry (Å, ).
1
H NMR (D2O, p.p.m.): 1.64 (6H, s, C—CH3, C—CH3), 2.77 (6H, s, D—H A D—H H A D A D—H A
N—CH3, N—CH3), 3.84 (2H, s, CH2), 4.67 (DHO). Analysis calcu-
lated for C9H15NO4: C 53.72, H 7.51, N 6.96%; found: C 53.60, H 7.64, N1—H1 O3 0.86 (2) 2.51 (2) 3.0696 (16) 124 (1)
N1—H1 O3i 0.86 (2) 2.01 (2) 2.7740 (15) 148 (2)
N 6.98%.
Symmetry code: (i) x þ 1; y þ 1; z þ 1.
Crystal data
All H atoms were located in a difference Fourier map and refined
C9H15NO4 Z=2 isotropically [C—H = 0.94 (2)–1.010 (17) Å].
Mr = 201.22 Dx = 1.317 Mg m3
Triclinic, P1 Mo K radiation Data collection: RAPID-AUTO (Rigaku Corporation, 2001); cell
a = 6.7922 (5) Å Cell parameters from 2555 refinement: RAPID-AUTO; data reduction: CrystalStructure
b = 8.4862 (8) Å reflections (Rigaku/MSC & Rigaku Corporation, 2004); program(s) used to
c = 9.1518 (8) Å = 3.0–27.3 solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to
= 99.810 (6) = 0.10 mm1
refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics:
= 101.532 (3) T = 293 (2) K
= 92.919 (5) Prism, colourless SHELXTL (Bruker, 1998); software used to prepare material for
V = 507.33 (8) Å3 0.50 0.48 0.42 mm publication: CrystalStructure.
Data collection
Rigaku R-AXIS RAPID 1519 reflections with I > 2(I) References
diffractometer Rint = 0.015
! scans max = 25.0 Bruker (1998). SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.
Absorption correction: none h = 7 ! 8 Li, J. H. & Chen, Z. C. (2000). Synth. Commun. 30, 2317–2323.
2699 measured reflections k = 10 ! 10 Li, J. H., Chen, Z. C. & Su, W. K. (2001). Synth. Commun. 31, 409–413.
1785 independent reflections l = 10 ! 10 McNab, H. (1978). Chem. Soc. Rev. 7, 345–358.
Pihlaja, K. & Seilo, M. (1968). Acta Chem. Scand. 22, 3053–3062.
Refinement Pihlaja, K. & Seilo, M. (1969). Acta Chem. Scand. 23, 3003–3010.
Rigaku Corporation (2001). RAPID-AUTO. Rigaku Corporation, Tokyo,
Refinement on F 2 w = 1/[ 2(Fo2) + (0.0603P)2
Japan.
R[F 2 > 2(F 2)] = 0.039 + 0.079P]
Rigaku/MSC & Rigaku Corporation (2004). CrystalStructure. Version 3.6.0.
wR(F 2) = 0.102 where P = (Fo2 + 2Fc2)/3
Rigaku/MSC, 9009 New Trails Drive, The Woodlands, TX 77381-5209, USA,
S = 1.08 (/)max < 0.001
and Rigaku Corporation, Tokyo, Japan.
1785 reflections max = 0.16 e Å3
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of
187 parameters min = 0.25 e Å3
Göttingen, Germany.
All H-atom parameters refined
Acta Cryst. (2005). E61, o3106–o3107 Li et al. C9H15NO4 o3107
