4,4-Bis(hydroxymethyl)-2-phenyl-2-oxazoline

: The title compound, 4,4-bis(hydroxymethyl)-2-phenyl-2-oxazoline 2 , a well-known substance, was resynthesized in high yields through a conventional method. The structure of compound 2 was characterized for the ﬁrst time by a single-crystal X-ray structure determination. The compound was further established through NMR spectroscopy (1D and 2D). In the molecular packing, two molecules of 4,4-bis(hydroxymethyl)-2-phenyl-2-oxazoline interact through H-Bonds to deﬁne “dimers” in which phenyl groups interact especially using π . . . π contact. Å and 1.480 Å, respectively. The lower value of 1.269 Å clearly indicates a double bond character in C7–N1. In addition, the conjugation of the electronic clouds of the C7–N1 bond and the aromatic ring make the H bonds stronger on the benzene ring side than on the ethylenic one, O3...H5-C5: 2.470 Å, O2...C9-H9B: 2.618 Å. In the phenyl group, all the angles C-C-C or C-C-H are around 120 ◦ and is a completely planar molecule. The ﬁve-membered oxazoline ring adopts an envelope conformation in the compound and makes a dihedral angle of 3.89(6) ◦ with its phenyl substituent.


Synthesis
Compound 2 was resynthesized using Billman's method [18]. It was obtained in an 85% yield from condensation of a commercial product 2-amino-2-(hydroxymethyl)propane-1,3-diol 1 ) and benzoic acid in reflux of xylene using as material dean-stark to immediately remove the water formed (Scheme 1). A single crystal of the title compound was obtained by recrystallization from ether/hexane and ts structure was established on the basis of NMR spectroscopy ( Figure 1) and X-ray diffraction. The efinite assignment of the chemical shifts of protons and carbons are shown in Table 1.
We first produced the 1 H-NMR spectrum of the product 2 in methanol CD3OD but we noted the bsence of the signals of the protons of the two alcohol functions, and after we produced the same pectrum, but this time in the hot acetone, hence, the appearance of a signal widened to 3.8 ppm orresponding to the two alcoholic protons. A single crystal of the title compound was obtained by recrystallization from ether/hexane and its structure was established on the basis of NMR spectroscopy ( Figure 1) and X-ray diffraction. The definite assignment of the chemical shifts of protons and carbons are shown in Table 1. A single crystal of the title compound was obtained by recrystallization from ether/hexane and its structure was established on the basis of NMR spectroscopy ( Figure 1) and X-ray diffraction. The definite assignment of the chemical shifts of protons and carbons are shown in Table 1.
We first produced the 1 H-NMR spectrum of the product 2 in methanol CD3OD but we noted the absence of the signals of the protons of the two alcohol functions, and after we produced the same spectrum, but this time in the hot acetone, hence, the appearance of a signal widened to 3.8 ppm corresponding to the two alcoholic protons.   We first produced the 1 H-NMR spectrum of the product 2 in methanol CD 3 OD but we noted the absence of the signals of the protons of the two alcohol functions, and after we produced the same spectrum, but this time in the hot acetone, hence, the appearance of a signal widened to 3.8 ppm corresponding to the two alcoholic protons.

X-ray Structure Determination of 2
In the absence of X-ray crystallographic data determination for compound 2, a crystallographic study was performed. The X-ray diffraction analysis revealed that compound 2 crystallizes in the monoclinic space group C2/c with four molecules per unit cell. The asymmetric unit contains one molecule 4,4-bis(hydroxymethyl)-2-phenyl-2-oxazoline ( Figure 2). All C-C, C=C, C-N, C=N, and C-O bond lengths are in the normal range and are comparable to those in related compounds [17,[25][26][27]. In the oxazoline ring, the C7-N1 and C10-N1 bond lengths are 1.269 Å and 1.480 Å, respectively. The lower value of 1.269 Å clearly indicates a double bond character in C7-N1. In addition, the conjugation of the electronic clouds of the C7-N1 bond and the aromatic ring make the H bonds stronger on the benzene ring side than on the ethylenic one, O3...H5-C5: 2.470 Å, O2...C9-H9B: 2.618 Å. In the phenyl group, all the angles C-C-C or C-C-H are around 120 • and is a completely planar molecule. The five-membered oxazoline ring adopts an envelope conformation in the compound and makes a dihedral angle of 3.89(6) • with its phenyl substituent.
Molbank 2020, 2020, x 3 of 6 In the absence of X-ray crystallographic data determination for compound 2, a crystallographic study was performed. The X-ray diffraction analysis revealed that compound 2 crystallizes in the monoclinic space group C2/c with four molecules per unit cell. The asymmetric unit contains one molecule 4,4-bis(hydroxymethyl)-2-phenyl-2-oxazoline ( Figure 2). All C-C, C=C, C-N, C=N, and C-O bond lengths are in the normal range and are comparable to those in related compounds [17,[25][26][27]. In the oxazoline ring, the C7-N1 and C10-N1 bond lengths are 1.269 Å and 1.480 Å, respectively. The lower value of 1.269 Å clearly indicates a double bond character in C7-N1. In addition, the conjugation of the electronic clouds of the C7-N1 bond and the aromatic ring make the H bonds stronger on the benzene ring side than on the ethylenic one, O3...H5-C5: 2.470 Å, O2...C9-H9B: 2.618 Å. In the phenyl group, all the angles C-C-C or C-C-H are around 120° and is a completely planar molecule. The five-membered oxazoline ring adopts an envelope conformation in the compound and makes a dihedral angle of 3.89(6)° with its phenyl substituent.  Within the 3D framework of the title compound, two molecules 4,4-bis(hydroxymethyl)-2 -phenyl-2-oxazoline interact through H-Bonds as depicted on Figure 3 to define "dimers" in which phenyl group interact especially using π . . . π contact. Two neighbouring such "dimers" use the same interactions to propagate in the 3D. The phenyl groups in neighbouring molecules are set in planes making a dihedral angle of 5.881(66) • .

General Methods and Physical Measurements
Melting point was determined with an Electrothermal melting point apparatus and was uncorrected. NMR spectra ( 1 H and 13 C) were recorded on a Bruker AM 300 spectrometer (operating at 300 MHz for 1 H, at 75 MHz for 13 C) (Bruker Analytische Messtechnik GmbH, Rheinstetten, Germany). NMR data are listed in ppm and are reported relative to tetra-methylsilane ( 1 H, 13 C); residual solvent peaks being used as internal standard. X-ray diffraction data were collected at room temperature with a Bruker APEXII CCD detector diffractometer (CNRST-Rabat).

General Methods and Physical Measurements
Melting point was determined with an Electrothermal melting point apparatus and was uncorrected. NMR spectra ( 1 H and 13 C) were recorded on a Bruker AM 300 spectrometer (operating at 300 MHz for 1 H, at 75 MHz for 13 C) (Bruker Analytische Messtechnik GmbH, Rheinstetten, Germany). NMR data are listed in ppm and are reported relative to tetra-methylsilane ( 1 H, 13 C); residual solvent peaks being used as internal standard. X-ray diffraction data were collected at room temperature with a Bruker APEXII CCD detector diffractometer (CNRST-Rabat).

Conclusions
In summary, we obtained the X-ray crystal structure of 4,4-bis(hydroxymethyl)-2-phenyl -2-oxazoline 2, for the first time and found it to have one independent molecule per asymmetric unit. In the molecular packing, supramolecular dimers are formed; this is mediated by C-H . .  Figure S1: 13 C-NMR spectrum of compound 2, Figure S2: 1 H-NMR spectrum (in acetone-d 6 ) of compound 2, Figure S3: 1 H-NMR spectrum (in CD 3 OD) of compound 2, Figure S4: Heteronuclear 1 H-13 C spectrum of compound 2 and crystallographic data for compound 2 in crystallographic information file (CIF) format. CCDC 2015223 also contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via the Cambridge Crystallographic Data Centre http://www.ccdc.cam.ac.uk/conts/retrieving.html.