CN103086933A

CN103086933A - Preparation method of phenyl isothiocyanate

Info

Publication number: CN103086933A
Application number: CN2013100261401A
Authority: CN
Inventors: 张泽; 吴浩浩
Original assignee: Anhui Polytechnic University
Current assignee: Anhui Polytechnic University
Priority date: 2013-01-23
Filing date: 2013-01-23
Publication date: 2013-05-08
Anticipated expiration: 2033-01-23
Also published as: CN103086933B

Abstract

The invention discloses a preparation method of phenyl isothiocyanate. The preparation method comprises the steps of: putting substituted aniline, carbon disulfide and potassium hydroxide in molar ratio of 1: (2-3):1 in a mechanical-chemical reactor for vibration and grinding, extracting, drying and filtering after reaction is ended, evaporating filtrate to dryness and then carrying out silica-gel column chromatography isolation, thus obtaining the phenyl isothiocyanate. According to the preparation method, reaction is completed in one step under the condition of inexistence of solvents, operation is simple, needed reaction time is short, and environment pollution is avoided; chloroformates or other high-corrosion raw materials with strong toxicity are not used for decomposing dithiocarbamate generated in a reaction process so that reaction is safe.

Description

A kind of preparation method of PITC

Technical field

The present invention relates to a kind of preparation method of PITC.

Background technology

The preparation method of present PITC multiplex thiophosgene, acyl chlorides, acid anhydrides or other highly corrosive raw material to strong toxicity, come the dithiocar-bamate that produces in the decomposition reaction process, and be all to carry out in organic solvent, aftertreatment is loaded down with trivial details, and environmental pollution is serious.In prior art, the method of relative environmental protection be by amine and dithiocarbonic anhydride in organic solvent under the highly basic effect addition prepare and generate the aminodithioformic acid sodium salt, then react with the carbonochloridic acid ester, again with soda lye hydrolysis and wet distillation, slough alcohol and thiocarbonic acid SOH gas is realized, complex steps, operational difficulty.So far do not utilize the direct method for preparing PITC of one step of solvent-free technology of mechanochemistry to be in the news.

Summary of the invention

The present invention is directed to the deficiencies in the prior art, a kind of preparation method of PITC is provided, its purpose is that technical problem to be solved by this invention is to provide under a kind of condition of no solvent, directly prepares the safe green environmental-friendly new method of PITC.

To achieve these goals, the technical solution used in the present invention is:

The preparation method of PITC comprises the following steps claims

(a) be 1:(2 ~ 3 with aniline or substituted aniline, dithiocarbonic anhydride and alkali in molar ratio): 1 ratio is put in the mechanico-chemical reaction tank, chemical reaction pot is tightened on the Swing Arm of mechanico-chemical reaction device, concussion reaction 40-60min;

(b) after the question response end, after the resultant in retort is extracted with ethyl acetate/water, collect the ethyl acetate phase, dry, filtration, the filtrate evaporate to dryness separates by silica gel column chromatography, obtains at last PITC.

Described substituted aniline is one of following: o-toluidine, ORTHO ANISIDINE, Ortho-Chloro aniline, to monomethylaniline, P-nethoxyaniline, p-Chlorobenzoic acid amide, para-bromoaniline or p-Nitroaniline.

In described step (a), alkali used is sodium carbonate or salt of wormwood or potassium hydroxide or triethylamine.

In described step (a), reaction concussion set of frequency is 30Hz.

Use dried over mgso in described step (b).

Ethyl acetate in described step (b) and the volume ratio of water are 1:1.

Compared with prior art, the invention has the advantages that:

The first, compare with an organic solvent preparation method in prior art, the present invention is in solvent-free situation, and a step is completed reaction, and simple to operate, the required reaction times is short, and environmentally safe;

The second, do not come with the stronger carbonochloridic acid ester of toxicity or other class highly corrosive raw material the dithiocar-bamate that produces in the decomposition reaction process, react safer;

The 3rd, the method for employing mechanical mill, the equipment that uses in reaction is simple.

Description of drawings

The hydrogen nuclear magnetic resonance spectrogram of Fig. 1 embodiment 1;

The hydrogen nuclear magnetic resonance spectrogram of Fig. 2 embodiment 2;

The hydrogen nuclear magnetic resonance spectrogram of Fig. 3 embodiment 3;

The hydrogen nuclear magnetic resonance spectrogram of Fig. 4 embodiment 4;

The hydrogen nuclear magnetic resonance spectrogram of Fig. 5 embodiment 5;

The hydrogen nuclear magnetic resonance spectrogram of Fig. 6 embodiment 6;

The carbon-13 nmr spectra figure of Fig. 7 embodiment 1;

The carbon-13 nmr spectra figure of Fig. 8 embodiment 2;

The carbon-13 nmr spectra figure of Fig. 9 embodiment 3;

The carbon-13 nmr spectra figure of Figure 10 embodiment 4;

The carbon-13 nmr spectra figure of Figure 11 embodiment 5;

The carbon-13 nmr spectra figure of Figure 12 embodiment 6.

Embodiment

Mechanico-chemical reaction device of the present invention is the German Lay mechanico-chemical reaction device (MM400) of speeding.

Below in conjunction with specific embodiment, the present invention is conducted further description, but protection scope of the present invention is not limited in this:

Embodiment 1

Take the 1.23g P-nethoxyaniline, 2.28 g dithiocarbonic anhydride and 0.56g potassium hydroxide, be placed in the mechanico-chemical reaction tank of a 25mL, parallel feeding intake in another same mechanico-chemical reaction tank is fixed on German Lay and speeds on the Swing Arm of mechanico-chemical reaction device (MM400) after screwing hermetic.React 40min under the concussion frequency of 30Hz.After question response finishes, the reaction mixture of two tanks extracts with ethyl acetate/water, merge and collect the ethyl acetate phase, filter after anhydrous magnesium sulfate drying, the filtrate evaporate to dryness separates (eluent: V sherwood oil/V ethyl acetate=8:1) get 1.55g to anisole lsothiocyanates sterling by silica gel column chromatography, state is the slightly yellowy solid of white, and productive rate is 94%.

Embodiment 2-9

Adopt aniline or different substituted anilines to prepare PITC, experimental implementation the results are shown in Table 1. with embodiment 1

Table 1 is the PITC of raw material preparation for aniline or different substituted aniline

Table 1

(wherein resonant frequency is 300Hz to the product nmr spectrum of embodiment 1-6, and solvent for use is CDCl ₃) analytical results is as follows:

Product 1: to the anisole lsothiocyanates

¹HNMR:?7.16?(d,?J?=?8.6?Hz,?2H,?ArH),?6.85?(d,?J?=?8.6?Hz,?2H,?ArH),?3.80?(s,?3H,?OCH ₃);? ¹³CNMR:?158.6,?133.9?(NCS),?127.0,?123.5,?114.8,?55.6?(OCH ₃).

Product 2: PhNCS

¹HNMR:?7.15–7.31?(m,?5H,?ArH);? ¹³CNMR:?134.6?(NCS),?130.3,?128.5,?126.3,?124.7.

Product 3: o-methyl-benzene lsothiocyanates

¹HNMR:?7.19?(brs,?4H,?ArH),?2.39?(s,?3H,?CH ₃);? ¹³CNMR:?134.9,?133.8?(NCS),?130.7,?129.7,?127.4,?126.9,?125.9,?18.4?(CH ₃).

Product 4: O-methoxy PhNCS

¹HNMR:?7.27?(t,?J?=?8.1?Hz,?1H,?ArH),?7.14?(d,?J?=?7.5?Hz,?1H,?ArH),?6.93?(t,?J?=?8.1?Hz,?2H,?ArH),?3.94?(s,?3H,?OCH ₃);? ¹³CNMR:?155.6,?137.9?(NCS),?129.3,?125.8,?121.1,?119.3,?112.5,?56.4?(OCH ₃).

Product 5: adjacent chlorobenzene lsothiocyanates

¹HNMR:?7.35?(d,?J?=?7.2?Hz,?1H,?ArH),?7.11–7.18?(m,?3H,?ArH);? ¹³CNMR:?134.2?(NCS),?130.9,?129.6,?129.1,?126.9,?126.6,?125.6.

Product 6: to the methylbenzene lsothiocyanates

¹HNMR:?7.13?(br,?4H,?ArH),?2.35?(s,?3H,?CH ₃);? ¹³CNMR:?137.5,?134.2?(NCS),?130.2,?128.0,?125.5,?21.3.

Claims

1. the preparation method of a PITC, is characterized in that, said method comprising the steps of:

(b) after the question response end, after the mixed solution extraction of the resultant in retort with ethyl acetate and water, collect the ethyl acetate phase, dry, filtration, the filtrate evaporate to dryness separates by silica gel column chromatography, obtains at last PITC.

2. the preparation method of PITC as claimed in claim 1, it is characterized in that, described substituted aniline is one of following: o-toluidine, ORTHO ANISIDINE, Ortho-Chloro aniline, to monomethylaniline, P-nethoxyaniline, p-Chlorobenzoic acid amide, para-bromoaniline or p-Nitroaniline.

3. the preparation method of PITC as claimed in claim 1, is characterized in that, in described step (a), alkali used is sodium carbonate or salt of wormwood or potassium hydroxide or triethylamine.

4. the preparation method of PITC as claimed in claim 1, is characterized in that, in described step (a), reaction concussion set of frequency is 30Hz.

5. the preparation method of PITC as claimed in claim 1, is characterized in that, uses dried over mgso in described step (b).

6. the preparation method of PITC as claimed in claim 1, is characterized in that, the ethyl acetate in described step (b) and the volume ratio of water are 1:1.