4-Ethynyl-phenol

• CAS: 2200-91-1
• Catalog Number: ACM2200911
• Category: Main Products
• Molecular Weight: 118.13
• Molecular Formula: C₈H₆O
• Synonyms: 4-ETHYNYL-PHENOL;Phenol, 4-ethynyl- (9CI);Phenol, 4-ethynyl-
• IUPAC Name: 4-ethynylphenol
• Canonical SMILES: C#CC1=CC=C(C=C1)O
• InChI Key: HLXJEKPLQLVJGK-UHFFFAOYSA-N
• Boiling Point: 216.2ºC at 760 mmHg
• Flash Point: 97ºC
• Density: 1.12g/cm³
• Application: 4-Ethynyl-phenol, a clear yellow liquid, is primarily used as a fluorogenic and chromogenic probe for bacterial enzymes.
• Exact Mass: 118.04200

Case Study

Mannich reaction with 4-ethynyl-phenol

Bardamova, M. I., R. N. Myasnikova, and I. L. Kotlyarevskii. Bulletin of the Academy of Sciences of the USSR, Division of chemical science 16 (1967): 429-431.

Ethynylphenols represent a new class of compounds whose chemical properties are very interesting for studies involving several reaction centers present in the molecule. The introduction of electron donor groups into the core, on the one hand, dramatically increases the reactivity of the core and, on the other hand, also has an effect on the chemical behavior of the ethynyl group. If the mechanism of these reactions is correct, assuming that acetylene initially dissociates into a proton and an acetylene ion, the reactivity of ethynylphenol in reactions involving acetylenic hydrogens should be greatly reduced by the introduction of donor groups into the core. 3-methyl-4-ethynylphenol (Ia), 4-ethynyl-phenol (Ib) and 2-methoxy-4-ethynylphenol (Ic) were used for the studies. (Ia) was synthesized by replacing the carbonyl oxygen in 3-methyl-4-acetylphenol with chlorine using PC15 and then dehydrochlorinating the resulting chloride using NaNH2. It is an unstable compound obtained only as a benzoyl derivative (IV) by the Schotten-Baumann process. (Ia) oxidative condensation generates an unstable dehydrogenated dimer, the structure of which is confirmed by infrared spectroscopy, and is converted into the dibenzoyl derivative (V). The latter is also synthesized in the same manner as (Ia) from 2-methyl-4-benzoyloxyphenylacetylene (IV) 3-methylethyl-6-ethynylphenol (H), and it also forms a dehydrogenated dimer.
This compound is obtained by shaking 5 g of 4-ethynyl-phenol in a mixture of 15 ml of methanol, 13 g of ammonium chloride, 15 ml of water, 1 drop of ammonia and 4 g of CuCl in an oxygen atmosphere.

Regioselective cyclotrimerization of aryl alkynes such as 4-ethynyl phenol

Sen, Abhijit, et al. JACS Au 1.11 (2021): 2080-2087.

A complex poly(4-vinylpyridine) cobalt(II) (P4VP-CoCl) system was developed as a stable and reusable heterogeneous catalyst. The local structure near the Co atom was determined based on experimental data and theoretical calculations. The immobilized cobalt catalyst exhibited high selectivity and catalytic activity in the [2+2+2] cyclotrimerization of terminal aryl alkynes such as 4-ethynyl phenol. Using 0.033 mol% P4VPCoCl, the regioselective formation of 1,3,5-triarylbenzene was achieved without the formation of 1,2,4-triarylbenzene. Moreover, the reaction was efficiently carried out on a multi-gram scale (11 g). Moreover, the polymer-supported catalyst was successfully recovered and used three times. X-ray photoelectron spectroscopy analysis of the recovered catalyst indicated that the cobalt was in the +2 oxidation state. The 1,3,5-triarylbenzene derivatives were applied in molecular beam electron resists and the synthesis of polycyclic aromatic hydrocarbons.
The cyclotrimerization of phenylacetylene (1a) was investigated using P4VP-CoCl II as a heterogeneous Co catalyst. Interestingly, when 1a was reacted neat with 0.033 mol% II (330 mol ppm Co) in the presence of N,N-diisopropylethylamine (DIPEA, Hü nig base) at 150 °C for 24 h, the regioselective cycloreduction selectively gave 1,3,5-triphenylbenzene (2a) in 68% yield, and no 1,2,4-triphenylbenzene (3a) was detected. The reaction continued when 0.015 mol% II (150 mol ppm Co) was used to afford 2a in 59% yield. Increasing catalyst loading (0.066 mol% or 660 mol ppm Co) did not improve the reaction yield (entry 5). The reaction in xylene afforded 2a in 66% yield, whereas the reaction in toluene (40% yield) and DMF (trace) was slow. The reaction also afforded the desired product in lower yields in the presence of electron withdrawing groups. The lower yields were due to the formation of several byproducts. Unprotected 4-ethynylphenol (1m) was readily converted to the desired product 2m in 71% yield.

Custom Q&A

What is the molecular formula of 4-Ethynyl-phenol?

The molecular formula is C8H6O.

What are some synonyms of 4-Ethynyl-phenol?

Some synonyms include 4-ethynylphenol, 2200-91-1, 4-ethynyl-phenol, and 4-Hydroxyphenylacetylene.

What is the molecular weight of 4-Ethynyl-phenol?

The molecular weight is 118.13 g/mol.

When was 4-Ethynyl-phenol created?

It was created on August 8, 2005.

When was 4-Ethynyl-phenol last modified?

It was last modified on October 21, 2023.

What is the IUPAC name of 4-Ethynyl-phenol?

The IUPAC name is 4-ethynylphenol.

What is the InChI of 4-Ethynyl-phenol?

The InChI is InChI=1S/C8H6O/c1-2-7-3-5-8(9)6-4-7/h1,3-6,9H.

What is the InChIKey of 4-Ethynyl-phenol?

The InChIKey is HLXJEKPLQLVJGK-UHFFFAOYSA-N.

What is the canonical SMILES of 4-Ethynyl-phenol?

The canonical SMILES is C#CC1=CC=C(C=C1)O.

What is the CAS number of 4-Ethynyl-phenol?

The CAS number is 2200-91-1.

Synthetic Use

Upstream Synthesis Route 1

• 540-38-5
• 1066-54-2

• 2200-91-1

Reference: [1]Location in patent: scheme or table
Pennell, Matthew N.; Turner, Peter G.; Sheppard, Tom D.
[Chemistry - A European Journal, 2012, vol. 18, # 15, p. 4748 - 4758]

Downstream Synthesis Route 1

• 2200-91-1
• 626-02-8

• 37116-80-6
• 76961-97-2

Reference: [1] Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences, 2015, vol. 70, # 9, p. 637 - 641

Downstream Synthesis Route 2

• 2200-91-1
• 38289-27-9

• 402955-93-5

Reference: [1]Cho, Hyun Ju; Seo, Kyung; Lee, Cheol Ju; Yun, Hoseop; Chang, Ji Young
[Journal of Materials Chemistry, 2003, vol. 13, # 5, p. 986 - 990]

Downstream Synthesis Route 3

• 2200-91-1
• 38289-28-0

• 402955-94-6

Reference: [1]Macromolecules,2002,vol. 35,p. 1180 - 1189

* For details of the synthesis route, please refer to the original source to ensure accuracy.