CS265000B1 - 2-isocyanatobenzyltriphenylphosphonium bromide and its preparation - Google Patents

Abstract

The solution concerns a new substance 2- -isocyanatobenzyltriphenylphosphonium bromide. It is prepared by the action of triphenylphosphine on 2-bromomethylphenylisocyanate in an aprotic solvent at a temperature of 10 to 110 °C. The new compound can be used in the synthesis of five and six-membered nitrogen heterocycles.

Description

(57) The solution concerns a new substance 2-isocyanatobenzyltriphenylphosphonium bromide. It is prepared by the action of triphenylphosphine on 2-bromomethylphenylisocyanate in an aprotic solvent at a temperature of 10 to 110 °C. The new compound can be used in the synthesis of five and six-membered nitrogen heterocycles.

CS 265 000 Bl

The invention relates to 2-isocyanatobenzyltriphenylphosphonium bromide of formula I

w ch ₂ -p(c ₆ h ₅ ) ₃

Brother

J-)

N=C=O (I)

and the method of its preparation.

Functionalized isocyanates represent highly reactive intermediates suitable for the synthesis of acyclic and heterocyclic compounds with biological activity; additional reaction centers such as halogen, multiple bonds, which are conveniently located in the isocyanate molecule, allow the creation of synthetic equivalents of bioorganic heterocycles and their analogues from these substances.

A study of the literature showed that 2-isocyanatobenzyltriphenylphosphonium bromide is a new compound, not previously described in the literature.

The essence of the method for preparing 2-isocyanatobenzyltriphenylphosphonium bromide according to the invention consists in reacting 2-bromomethylphenylisocyanate of formula II

CH2 _- Br

N-C-O (ii) is reacted with triphenylphosphine in an aprotic organic solvent, preferably hexane, diethyl ether or toluene, in the temperature range of 10 to 110 °C.

2-Isocyanatobenzyltriphenylphosphonium bromide represents a new type of functionalized isocyanate suitable for the synthesis of six-membered nitrogen heterocycles (e.g. alkylidenoxindole derivatives). The advantage of its preparation method is the fact that the N=C=O group is not broken during the reaction.

The subject matter of the invention is illustrated, but not limited, by the following examples:

Example 1

A mixture of 21.2 g (0.1 mol) of 2-bromomethylphenylisocyanate and 26.2 g (0.1 mol) of triphenylphosphine was heated in 500 ml of anhydrous ether to boiling under a reflux condenser. After 1 hour, the reflux condenser was replaced by a descending condenser and the ether was slowly distilled off. The residue in the flask was ground to a powder, washed with ether and crystallized from dry acetonitrile. Yield 91%, m.p. 231-232 °C.

Example 2

A mixture of 21.2 g (0.1 mol) of 2-bromomethylphenylisocyanate and 26.2 g (0.1 mol) of triphenylphosphine in 250 ml of anhydrous toluene is heated to reflux for 1 hour. The toluene is evaporated under reduced pressure and the residue is crystallized from acetonitrile or acetone. Yield 87%, m.p. 231-232 °C.

The obtained 2-isocyanatobenzyltriphenylphosphonium bromide is a crystalline substance, mp 231-232°C (acetonitrile).

Molecular formula: ^26 ^H 20 ^BrNOP

Molecular weight: 474.2

3 265000 Elementary analysis: %c % H %N Quantity calculated: 65.82 4.43 2.95 Quantity found: 65.01 4.39 2.89 The structure of the compound according to the invention was proven with external IR and NMR methods.

IR spectrum: v, cm ³ (CHCl^) 2 265 (N=C=O) ^X H NMR spectrum: 0 , ppm (CDCip, 5.4 d 2H (CH ₂ < J (PH = 14 Hz), 6.78 to 7.91 m 19H (H-arom.).

Spectral measurements

Infrared spectra were measured on a Specord IR 75 spectrophotometer (Carl Ziess Jena). ³ H NMR spectra were measured on an 80 MHz Tesla BS 487 spectrophotometer.

Claims (2)

3 265000 Elemental analysis:% c% H% N Calcd .: 65.82 4.43 2.95 Amount Found: 65.01 4.39 2.89 The structure of the compound of the invention was demonstrated by the IR and NMR methods. IR spectrum: v, cm (CHCl 3) 2 265 (N = C = O) 1 H NMR Spectrum: δ, ppm (CDCl 3, 5.4 d 2H (CH 2, J (PH = 14 Hz), 6.78 to 7) Spectral measurements Infrared spectra were measured on a Specord IR 75 spectrophotometer (Carl Ziess Jena). NMR spectra were measured on an 80 MHz spectrophotometer Tesla BS 487. OBJECT OF THE INVENTION 1. 2-Isocyanatobenzyltriphenylphosphonium bromide vzoroa I w ch2 - p (c6h N = C = O 5 * 3 Br 2. A process according to claim 1, wherein the 2-isocyanatobenzyltriphenylphosphonium bromide according to clause 1 of the formula I2 is bromo-methylphenylisocyanate of formula II CH2-Br N = C = O (II) with triphenylphosphine in an aprotic organic solvent, preferably hexane, diethyl ether or toluene, in the temperature of 10 to 110 ° C.