2H,3H,4H,6H,7H,8H,9H,10H-pyrimido[1,2-a]azepine

• ChemBase ID: 67496
• Molecular Formular: C9H16N2
• Molecular Mass: 152.23674
• Monoisotopic Mass: 152.13134852
• SMILES: N12CCCCCC1=NCCC2
• Canonical SMILES: C1CCN2C(=NCCC2)CC1
• InChI: InChI=1S/C9H16N2/c1-2-5-9-10-6-4-8-11(9)7-3-1/h1-8H2
• InChIKey: GQHTUMJGOHRCHB-UHFFFAOYSA-N

NAMES AND DATABASE IDS

Names

• IUPAC name: 2H,3H,4H,6H,7H,8H,9H,10H-pyrimido[1,2-a]azepine
• IUPAC Traditional name: 1,8-diazabicycloundec-7-ene
• Synonyms: DBU; 1,8-Diazabicyclo[5.4.0]undec-7-ene; 2,3,4,6,7,8,9,10-Octahydropyrimidol[1,2-a]azepine; 1,8-Diazabicyclo[5.4.0]undec-7-ene; DBU,Diazabicycloundecene; 1,8-Diazabicycloundec-7-ene; DBU solution; 1,8-Diazabicyclo[5.4.0]undec-7-ene solution; 2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepine; 2,3,4,6,7,8,9,10-Octahydropyrimido[1,2-a]azepine; DBU; 1,8-Diazabicyclo-[5,4,0]undec-7-ene; 2,3,4,6,7,8,9,10-八氢嘧啶并[1,2-a]氮杂卓; 1,8-二氮杂双环[5.4.0]十一碳-7-烯; 1,8-二氮双环[5.4.0]十一-7-烯; DBU 溶液; 1,8-二氮杂双环[5.4.0]十一碳-7-烯 溶液

Database IDs

• CAS Number: 6674-22-2
• EC Number: 229-713-7
• MDL Number: MFCD00006930
• Beilstein Number: 508906
• PubChem SID: 24860258; 24860259; 162033231; 24848373
• PubChem CID: 81184
• Chemspider ID: 73246
• Wikipedia Title: 1,8-Diazabicycloundec-7-ene

CALCULATED PROPERTIES

• H Acceptors: 2
• H Donor: 0
• LogD (pH = 5.5): -1.607904
• LogD (pH = 7.4): -1.5941415
• Log P: 0.80737644
• Molar Refractivity: 46.6048 cm^3
• Polarizability: 17.711895 Å^3
• Polar Surface Area: 15.6 Å^2
• Rotatable Bonds: 0
• Lipinski's Rule of Five: true

PROPERTIES

Physical Property

• Apperance: Colorless liquid
• Melting Point: -70°C; -70°C
• Boiling Point: 115 °C/11 mmHg(lit.); 261°C; 80-83 °C (0.6 mmHg), 261 °C (1 atm); 80-83 °C/0.6 mmHg(lit.); 80-83°C
• Flash Point: 0 °F; 116 °C; 116°C; 116°C(240°F); 119.9°C; -18 °C; 240.8 °F; 25 °F; -4 °C
• Density: 0.899 g/mL at 25 °C; 0.908 g/mL at 25 °C; 1.018; 1.018 g/mL at 25 °C(lit.); 1.018 g/mL liquid; 1.019 g/mL at 20 °C(lit.); 1.020
• Refractive Index: 1.5220; n20/D 1.395; n20/D 1.425; n20/D 1.522-1.524(lit.); n20/D 1.523
• Vapor Pressure: 5.3 mmHg ( 37.7 °C)
• Hydrophobicity(logP): 1.142
• pKa: ~12 (value for protonated form, pKa of a free base is ~24 -> C-H bond dissociation)
• pKb: ? (basicity)

Safety Information

• Storage Warning: Air Sensitive; Corrosive/Air Sensitive/Store under Argon; IRRITANT
• European Hazard Symbols: Corrosive (C); Flammable (F); X
• UN Number: 2924; 3267; UN3267
• German water hazard class: 2; 3
• Hazard Class: 3; 8
• Packing Group: 2; II
• Risk Statements: 11-19-34-37; 11-34-66-67; 22-34-52/53; R22 R34
• Safety Statements: 16-26-33-36/37/39-45; 16-29-33-36/37/39-45; 26-36/37/39-45; 26-36/37/39-45-60-61; S24 S25
• TSCA Listed: false; 是
• GHS Pictograms: GHS05; GHS06
• GHS Signal Word: Danger
• GHS Hazard statements: H290-H301-H314-H412; H301-H314-H318-H402-H412
• GHS Precautionary statements: P260-P301+P310-P303+P361+P353-P305+P351+P338-P405-P501A; P273-P280-P301 + P310-P305 + P351 + P338-P310
• Personal Protective Equipment: Faceshields, full-face respirator (US), Gloves, Goggles, multi-purpose combination respirator cartridge (US), type ABEK (EN14387) respirator filter
• RID/ADR: UN 2924 3/PG 2; UN 3267 8/PG 2

Product Information

• Purity: ≥98.0% (GC); ≥99.0% (GC); 95%; 95+%; 98%; 99%
• Concentration: 1 M in ethyl acetate; 1 M in THF
• Grade: puriss.; purum
• Empirical Formula (Hill Notation): C9H16N2

DETAILS

Sigma Aldrich - 139009

Application
Halogenated Diels-Alder adducts were dehydrohalogenated with this base, and the resulting activated 2,4-dienones were subjected to regio- and stereo-directed Michael additions, using Yamamoto′s reagent (CH3Cu · BF3).2
Used in a new synthesis of the ABCD ring system of Camptothecin.
Features and Benefits
Strong hindered amine base.
Packaging
25, 100, 500 g in glass bottle
Citation
An application review.1

Sigma Aldrich - 714852

Packaging
100 mL in Sure/Seal™

Sigma Aldrich - 714860

Packaging
100 mL in Sure/Seal™

Sigma Aldrich - 33482

Other Notes
Amidine base used for dehydrohalogenation reactions to olefins1; Further important applications are e.g.: esterification of carboxylic acids with alkyl halides2,3; Alkylation and acylation of active methylene compounds4

REFERENCES

• Widely used as a base in elimination reactions, cf 1,5-Diazabicyclo[4.3.0]non-5-ene, A13437. For use in dehydrohalogenation, see, e.g. Org. Synth. Coll., 9, 247, 663 (1998).
• For use in the enantioselective conversion of benzylic alcohols to azides, see Diphenylphosphonic azide, A12124.
• DBU forms hydrogen-bonded complexes with carboxylic acids, which can be alkylated in good yield by alkyl bromides or iodides, in a simple esterification procedure: Bull. Chem. Soc. Jpn., 51, 2401 (1978).
• In combination with NBS in MeOH, promotes the Hofmann rearrangement of amides to give methyl carbamates under mild conditions: J. Org. Chem., 62, 7495 (1997).
• For a review of the chemistry of DBU and other pyrimidoazepines, see: Adv. Heterocycl. Chem., 42, 84 (1987).
• Reportedly superior to imidazole for the preparation of TBDMS derivatives of, e.g. amines, thiols and carboxylic acids: Tetrahedron Lett., 26, 475 (1985).
• Promotes the epoxidation of ɑ?-unsaturated δ-lactones and other enones by t-butyl hydroperoxide, where other bases fail: Tetrahedron, 51, 8573 (1995).
• Used in the Wittig reaction to generate ylides stabilized by aryl or electron-withdrawing groups, see: Chem. Ber., 99, 2012 (1966).