organic compounds
2-tert-Butyl-4-methyl-6-(1,3-oxazinan-1-ylmethyl)phenol
aCollege of Chemistry & Chemical Engineering, South China University of Technology, Guangzhou, 510640, People's Republic of China, and bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: seikweng@um.edu.my
The title compound, C16H25NO2, which was synthesized by a Mannich reaction route, is a rare example of an organic compound containing the six-membered oxazine ring. The ring adopts a chair conformation and the N atom is pyramidal. The N atom serves as a hydrogen-bond acceptor to the phenolic OH group.
Related literature
The synthesis from 2-tert-butyl-4-methylphenol, 3-amino-1-propanol and formaldehyde is an example of carbon–carbon bond formation by the Mannich reaction. For another variation of the Mannich reaction involving 3-amino-1-propanol, see: Korepin et al. (2001).
Experimental
Crystal data
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Refinement
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Data collection: RAPID-AUTO (Rigaku, 2002); cell RAPID-AUTO; data reduction: CrystalClear (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
https://doi.org/10.1107/S1600536810012109/bt5237sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810012109/bt5237Isup2.hkl
2-tert-Butyl-4-methylphenol (2.24 g, 12.3 mmol), 3-amino-1-propanol (0.93 g, 12.3 mmol), 37% aqueous formaldehyde (1.83 ml, 24.6 mmol) and triethylamine (2.49 g, 24.6 mmol) in ethanol (50 ml) were heated for 6 hours. Slow evaporation of the filtrate gave light-yellow crystals in 70% yield.
Carbon-bound H-atoms were allowed to ride on their parent atoms (C–H 0.93– 0.97 Å) and their displacement parameters were set to 1.2–1.5Ueq(C). The hydroxy H-atom was located in a difference Fourier map, and was refined isotropically with a distance restraint of O–H 0.84±0.01 Å.
Due to the absence of anomalous scatterers, the
could not be determined, and, therefore, 1488 Friedel pairs were merged.Organic synthesis centers largely on stereoselective carbon–carbon and carbon–heteroatom bond-forming reactions; among such reactions is the class of Mannich reactions, which can be regarded as being the most important carbon–carbon bond-forming reaction. The reactions lead to β-aminocarbonyl compounds, which are important intermediates for pharmaceuticals.
One variation of the Mannich reaction involves the catalytic addition of an amine, R2NH, to an alkene or alkyne, i. e., hydroamination. In the 2-tert-butyl-4-methylphenol reacts with 3-amino-1-propanol to yield a compound having a 1,3-oxazinyl ring (Scheme I, Fig. 1). Such a ring is difficult to synthesis by conventional routes.
The synthesis from 2-tert-butyl-4-methylphenol, 3-amino-1-propanol and formaldehyde is an example of carbon–carbon bond formation by the Mannich reaction. For another variation of the Mannich reaction involving 3-amino-1-propanol, see: Korepin et al. (2001).
Data collection: RAPID-AUTO (Rigaku, 2002); cell
RAPID-AUTO (Rigaku, 2002); data reduction: CrystalClear (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).Fig. 1. Anisotropic displacement ellipsoid plot (Barbour, 2001) of the title compound at the 50% probability level; hydrogen atoms are drawn as spheres of arbitrary radius. |
C16H25NO2 | F(000) = 576 |
Mr = 263.37 | Dx = 1.134 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 12093 reflections |
a = 6.4740 (7) Å | θ = 3.1–27.5° |
b = 14.1928 (13) Å | µ = 0.07 mm−1 |
c = 16.7914 (16) Å | T = 293 K |
V = 1542.9 (3) Å3 | Block, yellow |
Z = 4 | 0.28 × 0.20 × 0.12 mm |
Rigaku R-AXIS Spider IP diffractometer | 2044 independent reflections |
Radiation source: fine-focus sealed tube | 1664 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
ω scan | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | h = −8→8 |
Tmin = 0.980, Tmax = 0.991 | k = −18→18 |
15222 measured reflections | l = −21→21 |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.117 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | w = 1/[σ2(Fo2) + (0.0739P)2 + 0.0371P] where P = (Fo2 + 2Fc2)/3 |
2044 reflections | (Δ/σ)max = 0.001 |
180 parameters | Δρmax = 0.14 e Å−3 |
1 restraint | Δρmin = −0.12 e Å−3 |
C16H25NO2 | V = 1542.9 (3) Å3 |
Mr = 263.37 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.4740 (7) Å | µ = 0.07 mm−1 |
b = 14.1928 (13) Å | T = 293 K |
c = 16.7914 (16) Å | 0.28 × 0.20 × 0.12 mm |
Rigaku R-AXIS Spider IP diffractometer | 2044 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 1664 reflections with I > 2σ(I) |
Tmin = 0.980, Tmax = 0.991 | Rint = 0.022 |
15222 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 1 restraint |
wR(F2) = 0.117 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | Δρmax = 0.14 e Å−3 |
2044 reflections | Δρmin = −0.12 e Å−3 |
180 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.8894 (2) | 0.48173 (11) | 0.62162 (8) | 0.0654 (4) | |
H1 | 0.972 (4) | 0.5284 (14) | 0.6242 (18) | 0.095 (9)* | |
O2 | 0.9444 (3) | 0.75355 (12) | 0.59189 (10) | 0.0816 (5) | |
N1 | 1.0668 (3) | 0.63695 (11) | 0.67909 (9) | 0.0550 (4) | |
C1 | 0.7719 (3) | 0.47819 (12) | 0.68939 (10) | 0.0494 (4) | |
C2 | 0.8294 (3) | 0.53321 (12) | 0.75571 (10) | 0.0506 (4) | |
C3 | 0.7081 (3) | 0.53034 (12) | 0.82338 (10) | 0.0536 (4) | |
H3 | 0.7451 | 0.5670 | 0.8670 | 0.064* | |
C4 | 0.5332 (3) | 0.47461 (12) | 0.82833 (10) | 0.0524 (4) | |
C5 | 0.4816 (3) | 0.42039 (12) | 0.76175 (10) | 0.0501 (4) | |
H5 | 0.3656 | 0.3819 | 0.7646 | 0.060* | |
C6 | 0.5953 (3) | 0.42121 (12) | 0.69126 (10) | 0.0468 (4) | |
C7 | 1.0274 (3) | 0.58874 (15) | 0.75529 (11) | 0.0594 (5) | |
H7A | 1.0222 | 0.6353 | 0.7975 | 0.071* | |
H7B | 1.1415 | 0.5465 | 0.7666 | 0.071* | |
C8 | 0.4047 (4) | 0.47229 (16) | 0.90293 (11) | 0.0731 (6) | |
H8A | 0.2749 | 0.4423 | 0.8919 | 0.110* | |
H8B | 0.3806 | 0.5355 | 0.9211 | 0.110* | |
H8C | 0.4765 | 0.4376 | 0.9434 | 0.110* | |
C9 | 0.5275 (3) | 0.36320 (13) | 0.61807 (10) | 0.0539 (4) | |
C10 | 0.4755 (5) | 0.43096 (16) | 0.54936 (12) | 0.0754 (6) | |
H10A | 0.3555 | 0.4673 | 0.5630 | 0.113* | |
H10B | 0.4484 | 0.3953 | 0.5019 | 0.113* | |
H10C | 0.5901 | 0.4725 | 0.5403 | 0.113* | |
C11 | 0.3358 (4) | 0.30415 (17) | 0.63527 (14) | 0.0745 (6) | |
H11A | 0.2244 | 0.3448 | 0.6510 | 0.112* | |
H11B | 0.3651 | 0.2605 | 0.6774 | 0.112* | |
H11C | 0.2971 | 0.2701 | 0.5882 | 0.112* | |
C12 | 0.7001 (4) | 0.29608 (16) | 0.59218 (13) | 0.0731 (6) | |
H12A | 0.6504 | 0.2558 | 0.5504 | 0.110* | |
H12B | 0.7423 | 0.2584 | 0.6368 | 0.110* | |
H12C | 0.8157 | 0.3320 | 0.5731 | 0.110* | |
C13 | 0.9229 (3) | 0.71409 (15) | 0.66757 (13) | 0.0668 (5) | |
H13A | 0.7828 | 0.6912 | 0.6742 | 0.080* | |
H13B | 0.9476 | 0.7621 | 0.7076 | 0.080* | |
C14 | 1.1466 (4) | 0.79381 (18) | 0.58285 (17) | 0.0839 (7) | |
H14A | 1.1654 | 0.8439 | 0.6215 | 0.101* | |
H14B | 1.1600 | 0.8208 | 0.5300 | 0.101* | |
C15 | 1.3100 (4) | 0.71942 (18) | 0.59488 (14) | 0.0743 (6) | |
H15A | 1.3017 | 0.6732 | 0.5524 | 0.089* | |
H15B | 1.4457 | 0.7482 | 0.5930 | 0.089* | |
C16 | 1.2798 (3) | 0.67164 (15) | 0.67383 (13) | 0.0633 (5) | |
H16A | 1.3757 | 0.6195 | 0.6790 | 0.076* | |
H16B | 1.3065 | 0.7158 | 0.7167 | 0.076* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0583 (9) | 0.0845 (9) | 0.0533 (7) | −0.0116 (8) | 0.0156 (7) | −0.0123 (7) |
O2 | 0.0656 (10) | 0.0945 (10) | 0.0847 (10) | −0.0108 (9) | −0.0202 (8) | 0.0295 (9) |
N1 | 0.0417 (8) | 0.0652 (8) | 0.0579 (8) | −0.0029 (7) | −0.0030 (7) | 0.0015 (7) |
C1 | 0.0461 (9) | 0.0594 (8) | 0.0427 (8) | 0.0024 (8) | 0.0025 (7) | −0.0022 (7) |
C2 | 0.0480 (10) | 0.0563 (9) | 0.0474 (8) | 0.0045 (8) | −0.0048 (7) | 0.0002 (8) |
C3 | 0.0618 (11) | 0.0578 (9) | 0.0412 (8) | 0.0048 (9) | −0.0042 (8) | −0.0049 (7) |
C4 | 0.0547 (10) | 0.0583 (8) | 0.0443 (8) | 0.0077 (8) | 0.0048 (8) | −0.0005 (8) |
C5 | 0.0474 (10) | 0.0540 (8) | 0.0491 (8) | 0.0026 (8) | 0.0026 (7) | 0.0007 (7) |
C6 | 0.0456 (9) | 0.0517 (8) | 0.0431 (7) | 0.0058 (7) | −0.0011 (7) | −0.0018 (7) |
C7 | 0.0526 (11) | 0.0719 (10) | 0.0537 (9) | −0.0032 (10) | −0.0084 (9) | 0.0020 (9) |
C8 | 0.0795 (16) | 0.0877 (13) | 0.0519 (11) | 0.0033 (13) | 0.0197 (10) | −0.0034 (10) |
C9 | 0.0553 (11) | 0.0637 (10) | 0.0428 (8) | 0.0006 (9) | −0.0051 (8) | −0.0044 (8) |
C10 | 0.0868 (17) | 0.0854 (13) | 0.0541 (10) | −0.0005 (13) | −0.0201 (11) | 0.0065 (10) |
C11 | 0.0764 (16) | 0.0823 (13) | 0.0649 (12) | −0.0191 (12) | −0.0065 (11) | −0.0106 (11) |
C12 | 0.0834 (17) | 0.0754 (12) | 0.0606 (11) | 0.0122 (13) | 0.0005 (11) | −0.0172 (10) |
C13 | 0.0492 (11) | 0.0760 (11) | 0.0752 (13) | 0.0046 (10) | −0.0018 (11) | 0.0095 (11) |
C14 | 0.0771 (17) | 0.0884 (14) | 0.0861 (16) | −0.0235 (14) | −0.0163 (14) | 0.0215 (13) |
C15 | 0.0625 (14) | 0.0911 (14) | 0.0694 (13) | −0.0203 (12) | 0.0040 (11) | −0.0028 (11) |
C16 | 0.0458 (10) | 0.0732 (11) | 0.0708 (12) | −0.0052 (9) | −0.0033 (10) | −0.0011 (10) |
O1—C1 | 1.370 (2) | C9—C11 | 1.526 (3) |
O1—H1 | 0.852 (10) | C9—C12 | 1.531 (3) |
O2—C13 | 1.396 (3) | C9—C10 | 1.539 (3) |
O2—C14 | 1.436 (3) | C10—H10A | 0.9600 |
N1—C13 | 1.450 (3) | C10—H10B | 0.9600 |
N1—C16 | 1.467 (3) | C10—H10C | 0.9600 |
N1—C7 | 1.473 (2) | C11—H11A | 0.9600 |
C1—C6 | 1.401 (3) | C11—H11B | 0.9600 |
C1—C2 | 1.410 (2) | C11—H11C | 0.9600 |
C2—C3 | 1.382 (3) | C12—H12A | 0.9600 |
C2—C7 | 1.505 (3) | C12—H12B | 0.9600 |
C3—C4 | 1.384 (3) | C12—H12C | 0.9600 |
C3—H3 | 0.9300 | C13—H13A | 0.9700 |
C4—C5 | 1.398 (2) | C13—H13B | 0.9700 |
C4—C8 | 1.504 (2) | C14—C15 | 1.508 (4) |
C5—C6 | 1.394 (2) | C14—H14A | 0.9700 |
C5—H5 | 0.9300 | C14—H14B | 0.9700 |
C6—C9 | 1.543 (2) | C15—C16 | 1.502 (3) |
C7—H7A | 0.9700 | C15—H15A | 0.9700 |
C7—H7B | 0.9700 | C15—H15B | 0.9700 |
C8—H8A | 0.9600 | C16—H16A | 0.9700 |
C8—H8B | 0.9600 | C16—H16B | 0.9700 |
C8—H8C | 0.9600 | ||
C1—O1—H1 | 110 (2) | C9—C10—H10B | 109.5 |
C13—O2—C14 | 110.29 (18) | H10A—C10—H10B | 109.5 |
C13—N1—C16 | 110.01 (15) | C9—C10—H10C | 109.5 |
C13—N1—C7 | 110.80 (16) | H10A—C10—H10C | 109.5 |
C16—N1—C7 | 111.79 (16) | H10B—C10—H10C | 109.5 |
O1—C1—C6 | 119.54 (15) | C9—C11—H11A | 109.5 |
O1—C1—C2 | 119.30 (17) | C9—C11—H11B | 109.5 |
C6—C1—C2 | 121.15 (16) | H11A—C11—H11B | 109.5 |
C3—C2—C1 | 118.89 (18) | C9—C11—H11C | 109.5 |
C3—C2—C7 | 120.23 (16) | H11A—C11—H11C | 109.5 |
C1—C2—C7 | 120.73 (17) | H11B—C11—H11C | 109.5 |
C2—C3—C4 | 122.09 (16) | C9—C12—H12A | 109.5 |
C2—C3—H3 | 119.0 | C9—C12—H12B | 109.5 |
C4—C3—H3 | 119.0 | H12A—C12—H12B | 109.5 |
C3—C4—C5 | 117.54 (16) | C9—C12—H12C | 109.5 |
C3—C4—C8 | 121.00 (16) | H12A—C12—H12C | 109.5 |
C5—C4—C8 | 121.45 (18) | H12B—C12—H12C | 109.5 |
C6—C5—C4 | 123.24 (18) | O2—C13—N1 | 111.13 (18) |
C6—C5—H5 | 118.4 | O2—C13—H13A | 109.4 |
C4—C5—H5 | 118.4 | N1—C13—H13A | 109.4 |
C5—C6—C1 | 117.06 (15) | O2—C13—H13B | 109.4 |
C5—C6—C9 | 121.45 (17) | N1—C13—H13B | 109.4 |
C1—C6—C9 | 121.49 (15) | H13A—C13—H13B | 108.0 |
N1—C7—C2 | 113.26 (15) | O2—C14—C15 | 110.27 (18) |
N1—C7—H7A | 108.9 | O2—C14—H14A | 109.6 |
C2—C7—H7A | 108.9 | C15—C14—H14A | 109.6 |
N1—C7—H7B | 108.9 | O2—C14—H14B | 109.6 |
C2—C7—H7B | 108.9 | C15—C14—H14B | 109.6 |
H7A—C7—H7B | 107.7 | H14A—C14—H14B | 108.1 |
C4—C8—H8A | 109.5 | C16—C15—C14 | 110.1 (2) |
C4—C8—H8B | 109.5 | C16—C15—H15A | 109.6 |
H8A—C8—H8B | 109.5 | C14—C15—H15A | 109.6 |
C4—C8—H8C | 109.5 | C16—C15—H15B | 109.6 |
H8A—C8—H8C | 109.5 | C14—C15—H15B | 109.6 |
H8B—C8—H8C | 109.5 | H15A—C15—H15B | 108.2 |
C11—C9—C12 | 107.79 (16) | N1—C16—C15 | 109.08 (18) |
C11—C9—C10 | 107.87 (19) | N1—C16—H16A | 109.9 |
C12—C9—C10 | 109.61 (18) | C15—C16—H16A | 109.9 |
C11—C9—C6 | 111.95 (16) | N1—C16—H16B | 109.9 |
C12—C9—C6 | 110.53 (17) | C15—C16—H16B | 109.9 |
C10—C9—C6 | 109.03 (15) | H16A—C16—H16B | 108.3 |
C9—C10—H10A | 109.5 | ||
O1—C1—C2—C3 | 178.97 (16) | C16—N1—C7—C2 | −166.73 (16) |
C6—C1—C2—C3 | 0.0 (3) | C3—C2—C7—N1 | −142.23 (18) |
O1—C1—C2—C7 | −5.4 (3) | C1—C2—C7—N1 | 42.2 (2) |
C6—C1—C2—C7 | 175.57 (16) | C5—C6—C9—C11 | −3.1 (2) |
C1—C2—C3—C4 | 0.6 (3) | C1—C6—C9—C11 | 177.96 (17) |
C7—C2—C3—C4 | −175.06 (16) | C5—C6—C9—C12 | −123.27 (19) |
C2—C3—C4—C5 | −0.1 (2) | C1—C6—C9—C12 | 57.8 (2) |
C2—C3—C4—C8 | 179.57 (19) | C5—C6—C9—C10 | 116.2 (2) |
C3—C4—C5—C6 | −1.0 (3) | C1—C6—C9—C10 | −62.8 (2) |
C8—C4—C5—C6 | 179.35 (17) | C14—O2—C13—N1 | −63.1 (2) |
C4—C5—C6—C1 | 1.5 (3) | C16—N1—C13—O2 | 62.4 (2) |
C4—C5—C6—C9 | −177.50 (16) | C7—N1—C13—O2 | −173.52 (16) |
O1—C1—C6—C5 | −179.96 (17) | C13—O2—C14—C15 | 59.0 (3) |
C2—C1—C6—C5 | −0.9 (2) | O2—C14—C15—C16 | −54.6 (3) |
O1—C1—C6—C9 | −1.0 (2) | C13—N1—C16—C15 | −56.7 (2) |
C2—C1—C6—C9 | 178.05 (16) | C7—N1—C16—C15 | 179.72 (18) |
C13—N1—C7—C2 | 70.2 (2) | C14—C15—C16—N1 | 53.5 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.85 (1) | 1.90 (2) | 2.665 (2) | 149 (3) |
Experimental details
Crystal data | |
Chemical formula | C16H25NO2 |
Mr | 263.37 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 6.4740 (7), 14.1928 (13), 16.7914 (16) |
V (Å3) | 1542.9 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.28 × 0.20 × 0.12 |
Data collection | |
Diffractometer | Rigaku R-AXIS Spider IP diffractometer |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.980, 0.991 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15222, 2044, 1664 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.117, 1.11 |
No. of reflections | 2044 |
No. of parameters | 180 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.14, −0.12 |
Computer programs: RAPID-AUTO (Rigaku, 2002), CrystalClear (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.85 (1) | 1.90 (2) | 2.665 (2) | 149 (3) |
Acknowledgements
We thank South China University of Technology and the University of Malaya for supporting this study.
References
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Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Korepin, A. G., Galkin, P. V., Glushakova, N. M., Lagodzinskaya, G. V., Loginova, M. V., Lodygina, V. P. & Eremenko, L. T. (2001). Russ. Chem. Bull. 50, 104–109. Web of Science CrossRef CAS Google Scholar
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Rigaku/MSC (2002). CrystalClear. Rigaku/MSC Inc., The Woodlands, Texas, USA. Google Scholar
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Organic synthesis centers largely on stereoselective carbon–carbon and carbon–heteroatom bond-forming reactions; among such reactions is the class of Mannich reactions, which can be regarded as being the most important carbon–carbon bond-forming reaction. The reactions lead to β-aminocarbonyl compounds, which are important intermediates for pharmaceuticals.
One variation of the Mannich reaction involves the catalytic addition of an amine, R2NH, to an alkene or alkyne, i. e., hydroamination. In the 2-tert-butyl-4-methylphenol reacts with 3-amino-1-propanol to yield a compound having a 1,3-oxazinyl ring (Scheme I, Fig. 1). Such a ring is difficult to synthesis by conventional routes.