CN109251208B

CN109251208B - Application of furopyran derivative in field antifreezing management of wheat

Info

Publication number: CN109251208B
Application number: CN201811151026.0A
Authority: CN
Inventors: 金敏; 李文倩; 骆永丽; 陈金; 庞党伟; 王振林
Original assignee: Shandong Agricultural University
Current assignee: Shandong Agricultural University
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-03-20
Anticipated expiration: 2038-09-29
Also published as: CN109251208A

Abstract

The invention provides a furopyran derivative with a chemical structure of formula(Ⅰ)

Wherein R is₁、R₂Each independently selected from-H, -CF₃-F or-OCH₃. The application of the furopyran derivative in field freezing injury management of wheat, in particular the effect in freezing injury prevention, is proved by a laboratory pot culture freezing resistance test and a field freezing injury management test of the wheat. The invention has low cost, simple operation and management and remarkable antifreezing effect, and is suitable for production, popularization and application.

Description

Application of furopyran derivative in field antifreezing management of wheat

Technical Field

The invention relates to application of a furopyran derivative in field antifreezing management of wheat.

Background

Wheat is one of the most important grain crops, and Shandong is one of the important areas of wheat production in China, and plays an important role in guaranteeing national grain production. However, in recent years, natural disasters, particularly early spring freezing damage (late spring cold), have caused great influence on Shandong wheat production.

Compared with the freezing injury in winter, the freezing injury of wheat in spring is more difficult to predict. The wheat cold injury in spring generally refers to late spring coldness (late spring coldness), which refers to a weather phenomenon that the temperature rises faster in early spring (generally 3 months) and is lower than the temperature in the later spring (generally 4 months or 5 months). The adverse effect of the cold of late spring on wheat can cause the unit ear number and the grain number of the ears to be obviously reduced, thereby causing yield reduction and even loss of harvest. The late spring cold freezing injury of wheat is mainly manifested by freezing of main stems, large tillers and young ears. Leaves were slightly dry and the appearance of external symptoms was not evident. The sequence of the frozen death of the young ears is that the young ears firstly stem and then tillere, the tillering of the frozen wheat is poor in the quality of the formed ears compared with the tillering before winter, and the formed ears are small in ear shape, small in ear number, low in thousand seed weight and reduced in 2-6 g in general.

The weather condition is an uncontrollable factor, in order to cope with the possibility of freezing damage of wheat in a key growth period, considering that the freezing degree of the wheat is related to various factors, field prevention and control management and breeding of wheat cold-resistant varieties are adopted in the current research, the field prevention and control management can achieve a certain degree of anti-freezing effect, but the limitation of factors such as overhigh cost or complex and difficult operation is not popularized and applied, the breeding effect of the wheat cold-resistant varieties is very little, and the research finds that the reaction difference of the wheat varieties to the freezing damage in spring is not obvious, and only the obvious difference exists between the recovery speed and the recovery degree of different varieties after being frozen. At present, the wheat is mainly prevented and remedied by cultivation technical measures in production, so the wheat field antifreezing management has important significance for preventing and controlling wheat freezing injury and improving wheat yield.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a furopyran derivative, and experiments prove the application of the furopyran derivative in field anti-freezing management of wheat. The invention has low cost, simple operation and management and remarkable antifreezing effect, and is suitable for production, popularization and application. The chemical structure is shown as formula (I):

wherein R is₁、R₂Each independently selected from-H, -CF₃-F or-OCH₃。

Further, the preferable structure is:

the synthetic route adopted by the furopyran derivative is as follows:

the above synthetic scheme is briefly described as follows:

in a suitable solvent, 2-ethoxy-4-methyl-3, 4-dihydro-2H-pyran is subjected to addition reaction with propargyl alcohol under the action of NIS to produce 6-ethoxy-3-iodo-4-methyl-2- (prop-2-yn-1-yloxy) tetrahydro-2H-pyran (intermediate 1). The solvent used may be dichloromethane, DCM, toluene, xylene, cyclohexane, tetrahydrofuran, N-dimethylformamide, DMSO, preferably dichloromethane.

In a proper solvent, the intermediate 1 generates a ring reaction under the action of a catalyst AIBN to generate 6-ethoxy-4-methyl-3-methylene-hexahydro-2H-furo [2,3-b ] pyran (intermediate 2); the solvent used may be toluene, xylene, N-heptane, N-hexane, cyclohexane, methylcyclohexane, tetrahydrofuran, N, N-dimethylformamide, DMSO, preferably tetrahydrofuran.

The C ═ C double bond in the intermediate 2 is oxidized under the action of ozone and dimethyl sulfide to produce 6-ethoxy-4-methyl-tetrahydro-furo [2,3-b ] pyran-3-one (intermediate 3);

carbonyl in intermediate 3 in NaBH₄To generate 6-ethoxy-4-methyl-hexahydro-2H-furo [2,3-b ] through reduction reaction]Pyran-3-ol (intermediate 4);

the hydroxyl group in intermediate 4 reacts with the corresponding ester in the presence of an inorganic base to produce the corresponding final product. The inorganic base used may be sodium hydroxide, potassium carbonate, sodium carbonate, cesium carbonate, potassium bicarbonate, sodium bicarbonate, preferably potassium carbonate.

The application of the furopyran derivative in field freezing injury management of wheat, in particular the effect in freezing injury prevention, is proved by a laboratory pot culture freezing resistance test and a field freezing injury management test of the wheat.

Detailed Description

Intermediate 1: synthesis of 6-ethoxy-3-iodo-4-methyl-2- (prop-2-yn-1-yloxy) tetrahydro-2H-pyran

2-ethoxy-4-methyl-3, 4-dihydro-2H-pyran (30mmol) and propargyl alcohol (45mmol) were dissolved inDichloromethane (50mL) and cooled to 0 ℃. N-iodosuccinimide (35mmol) was added portionwise to the solution over 30 minutes, which was warmed to room temperature and stirred for an additional 5 hours. The resulting solution was washed with brine (30mL), MgSO₄Dried and concentrated in vacuo. The crude oil was purified by column chromatography (flash silica, 10% EtOAc/petroleum ether) to give 6-ethoxy-3-iodo-4-methyl-2- (prop-2-yn-1-yloxy) tetrahydro-2H-pyran (intermediate 1) and 6-ethoxy-2-iodo-4-methyl-3- (prop-2-yn-1-yloxy) tetrahydro-2H-pyran (intermediate 1') as colorless oils, wherein intermediate 1 gave 1.5g, 14% yield.

Intermediate 1:¹H-NMR(400MHz,CDCl₃)δ:1.08(dd,3H),1.20(t,3H),2.01(m,1H),2.08(m,1H),2.21-2.33(m,2H),3.65(m,2H),4.01(m,1H),4.23(d,1H),4.35(d,1H),4.75(t,1H),5.16d,1H).¹³C-NMR(125MHz,CDCl₃)δ:15.03,17.64,33.39,38.73,41.53,56.12,64.32,75.03,78.24,98.18,99.16.LC-MS(ESI,pos,ion)m/z:325[M+H].

intermediate 2: synthesis of 6-ethoxy-4-methyl-3-methylene-hexahydro-2H-furo [2,3-b ] pyran

Intermediate 1(25mmol), tetrahydrofuran (25mmol) and AIBN (2.5mmol) were dissolved in benzene (50mL) and the solution refluxed for 8 hours, after completion of the reaction the solvent was removed in vacuo and the crude product was purified by column chromatography (flash silica, 10% EtOAc/petroleum ether) to give 6-ethoxy-4-methyl-3-methylene-hexahydro-2H-furo [2,3-b ] as a colorless oil]Pyran (intermediate 2), 4.11g, 83% yield.¹H-NMR(400MHz,CDCl₃)δ:0.95(dd,3H),1.20(t,3H),1.54(m,1H),1.76(m,2H),2.38(m,1H),3.29(m,1H),3.53(m,1H),3.99(d,1H),4.09(d,1H),4.69(t,1H),5.03(m,2H),5.43(d,1H).¹³C-NMR(125MHz,CDCl₃)δ:15.01,17.77,33.84,36.90,55.19,62.55,70.46,100.46,107.43,160.32.LC-MS(ESI,pos,ion)m/z:199[M+H].

Intermediate 3: synthesis of 6-ethoxy-4-methyl-tetrahydro-furo [2,3-b ] pyran-3-one

Intermediate 2(20mmol) was dissolved in dichloromethane (20mL) and the solution was cooled to-78 ℃. Ozone was bubbled into the solution for 2 hours, then the system was purged with nitrogen for 20 minutes. Dimethyl sulphide (40mmol) was added and the solution was stirred for 1 hour. The solvent was removed in vacuo and the crude product was purified by column chromatography (flash silica, 20% EtOAc/petroleum ether) to afford 6-ethoxy-4-methyl-tetrahydro-furo [2,3-b ] as a white crystalline solid]Pyran-3-one (intermediate 3), 2.56g, 64% yield.¹H-NMR(400MHz,CDCl₃)δ:0.95(dd,3H),1.20(t,3H),1.33(m,1H),1.58(m,1H),1.92(m,1H),2.56(m,1H),3.46(m,1H),3.70(m,1H),4.53(m,2H),4.69(t,1H),5.62(d,1H).¹³C-NMR(125MHz,CDCl₃)δ:15.01,17.77,32.06,37.54,60.18,62.55,74.45,100.23,100.57,212.02.LC-MS(ESI,pos,ion)m/z:201[M+H].

Intermediate 4: synthesis of 6-ethoxy-4-methyl-hexahydro-2H-furo [2,3-b ] pyran-3-ol

Intermediate 3(15mmol) was dissolved in ethanol (50mL) and NaBH was added at 0 deg.C₄(25mmol), reaction for 2 hours at temperature, addition of diethanolamine hydrochloride (15mmol), stirring overnight at room temperature, filtration, washing of the filter cake with ethyl acetate (20mL), concentration of the filtrate under reduced pressure to give 6-ethoxy-4-methyl-hexahydro-2H-furo [2,3-b ] as a colorless oil]Pyran-3-ol (intermediate 4), 2.56g, 85% yield.¹H-NMR(400MHz,CDCl₃)δ:0.92(dd,3H),1.20(t,3H),1.33(m,1H),1.58(m,1H),1.85(m,1H),2.24(m,1H),2.38(d,1H),3.46(m,1H),3.70(m,1H),3.85(m,1H),4.01(dd,1H),4.26(dd,1H),4.69(t,1H),5.45(d,1H).¹³C-NMR(125MHz,CDCl₃)δ:15.01,17.66,32.84,38.59,52.37,62.55,68.19,74.67,100.23,101.30.LC-MS(ESI,pos,ion)m/z:203[M+H].

Example 1: synthesis of 2, 5-dioxopyrrolidin-1-yl- (6-ethoxy-4-methyl-hexahydro-2H-furo [2,3-b ] pyran-3-yl) carbonate

Mixing PPh₃(10mmol) and acetic acid (13mmol) were dissolved in THF (50mL), then intermediate 4(10mmol) was added and the mixture stirred vigorously, followed by the addition of bis (2, 5-dioxopyrrolidin-1-yl) carbonate (11mmol) and stirring continued for 6 hours. The solvent was removed in vacuo, the crude compound was dissolved in ethanol (50mL), to which K was added₂CO₃(20 mmol). The mixture was stirred at room temperature overnight. The mixture was filtered and the solvent evaporated, then purified by column chromatography (flash silica, 20% EtOAc/petroleum ether) to give 2, 5-dioxopyrrolidin-1-yl- (6-ethoxy-4-methyl-hexahydro-2H-furan [2,3-b ] as a white solid]And pyran-3-yl) carbonate, 1.92g, yield 56%.¹H-NMR(400MHz,CDCl₃)δ:0.92(dd,3H),1.22(t,3H),1.35(m,1H),1.58(m,1H),2.24(m,1H),2.44(m,1H),2.80(s,4H),3.45(m,1H),3.70(m,1H),4.11(dd,1H),4.36(dd,1H),4.69(t,1H),4.92(m,1H),5.50(d,1H).¹³C-NMR(125MHz,CDCl₃)δ:15.01,17.66,25.44,33.65,38.59,47.95,62.55,66.93,77.04,100.23,102.08,151.71,169.28.LC-MS(ESI,pos,ion)m/z:344[M+H].

Example 2: synthesis of 3-fluoro-2, 5-dioxopyrrolidin-1-yl- (6-ethoxy-4-methyl-hexahydro-2H-furo [2,3-b ] pyran-3-yl) carbonate

Mixing PPh₃(10mmol) and acetic acid (13mmol) were dissolved in THF (50mL), then intermediate 4(10mmol) was added and the mixture stirred vigorously, followed by the addition of bis (3-fluoro-2, 5-dioxopyrrolidin-1-yl) carbonate (11mmol) and stirring continued for 6 hours. The solvent was removed in vacuo, the crude compound was dissolved in ethanol (50mL), to which K was added₂CO₃(20 mmol). The mixture was stirred at room temperature overnight. The mixture was filtered and the solvent evaporated, then purified by column chromatography (flash silica, 20% EtOAc/petroleum ether) to give a white solid3-fluoro-2, 5-dioxopyrrolidin-1-yl- (6-ethoxy-4-methyl-hexahydro-2H-furan [2, 3-b)]And pyran-3-yl) carbonate, 2.38g, yield 66%. LC-MS (ESI, pos, ion) M/z 362[ M + H [ ]].

Example 3: synthesis of 3-methoxy-2, 5-dioxopyrrolidin-1-yl- (6-ethoxy-4-methyl-hexahydro-2H-furo [2,3-b ] pyran-3-yl) carbonate

Mixing PPh₃(10mmol) and acetic acid (13mmol) were dissolved in THF (50mL), then intermediate 4(10mmol) was added and the mixture stirred vigorously, followed by the addition of bis (3-methoxy-2, 5-dioxopyrrolidin-1-yl) carbonate (11mmol) and stirring continued for 6 hours. The solvent was removed in vacuo, the crude compound was dissolved in ethanol (50mL), to which K was added₂CO₃(20 mmol). The mixture was stirred at room temperature overnight. The mixture was filtered and the solvent evaporated, then purified by column chromatography (flash silica, 20% EtOAc/petroleum ether) to give 3-methoxy-2, 5-dioxopyrrolidin-1-yl- (6-ethoxy-4-methyl-hexahydro-2H-furan [2,3-b ] as a white solid]And pyran-3-yl) carbonate, 2.17g, yield 58%. LC-MS (ESI, pos, ion) M/z 374[ M + H].

Example 4 to example 8:

the synthesis method is the same as example 1, and the synthesized products are as follows:

test example 1: laboratory pot culture frost test

First, test method

In a plastic basin (diameter 18 cm. times.20 c high)m) sowing the wheat variety into the seeds of 22 Jimai, and after germination of the seeds, carrying out normal culture conditions: irradiating for 14h every day, wherein the growth temperature is 25/15 deg.C (light/dark), and the illumination intensity is 240 μmol m^-2s^-1And the relative humidity is 60-75%. When the wheat plants grow to 6 leaves and one core, young spike observation is carried out, and the fact that the young spikes of the wheat are in the early stage of formation of the drug spacing at the moment is found, and corresponding to the fact that the wheat plants in the field are in the early stage of booting, the freezing damage suffered by the wheat plants in the development stage belongs to the freezing damage in spring.

Randomly dividing wheat plants at the initial stage of drug compartment formation into a drug application group and a control group, spraying the compound solution (the compound 0.1g/L and the aqueous solution with the Tween 40 concentration of 0.6 g/L) on the wheat plants in the drug application group, and carrying out continuous 3 d-1 ℃ spring freezing injury stress treatment on the wheat plants after 1d on the wheat plants in the drug application group by taking the solution which naturally flows down from leaves as a standard; and spraying distilled water on the wheat plants of the control group, and transferring the wheat plants into a low-temperature incubator for continuous 3 d-1 ℃ spring freezing stress treatment after 1 d. After the freezing injury is stressed for 3d, continuously culturing for 3d by adopting normal culture conditions, counting the freezing injury condition of the wheat young ear and calculating the freezing death rate (%) and the freezing resistance rate (%) of the young ear. Freezing resistance (%) (control group young ear freezing death rate-application group young ear freezing death rate)/(100-control group young ear freezing death rate) × 100

Second, experimental results

Laboratory potted plant antifreeze test results, see table below:

the determination result shows that after the wheat plant is stressed by freezing injury in spring at-1 ℃ for 3 days, the compound solution disclosed by the invention has the effects of reducing the freezing death rate of the young ears of the wheat and improving the freezing resistance rate, and the compound solution disclosed by the invention can enhance the resistance of the wheat plant to the freezing injury in spring.

Test example 2: wheat field antifreezing management test

First, test method

1. Experiment base

Experimental base of Shandong university of agriculture (Taian, near Central school district of Shandong university of agriculture).

2. Wheat variety

Jimai 22

3. Grading standard of freezing injury

No frozen spike at level 0;

freezing less than 20% of 1-grade young ears;

freezing 3-grade young ears to death by 20-50%;

5-grade young ears are frozen to death by 50% -80%;

7-grade infants are frozen to death by more than 80%;

all the 9 th-grade young ears are frozen to death.

4. Time of application

According to weather forecast of weather departments, the temperature of Shandong, Henan and the like is reduced with strong universality after 2018, 4 and 5, and the temperature reduction amplitude is over 10 ℃, so that the wheat faces cold injury in late spring. The administration time of the field test is 2018, 4 months, 3 days 13: 30-16: 30.

5. Grouping and administration of drugs

The test is divided into a drug application group and a control group, the drug application group is sprayed with the compound solution (the compound of the invention is 0.1g/L, and the Tween 40 concentration is 0.6 g/L), the control group is sprayed with the Tween solution without the compound of the invention, and the spraying standard is based on that the solution flows down from leaves naturally. Each treatment was repeated four times, each cell area being 25m². And (5) adopting a 5-point sampling method to observe the freeze injury condition of the young wheat ears.

6. Data analysis method

The young ear freezing injury index (%) is [ ∑ (number of diseased plants at each stage × relative stage value)/(total number of plants × 9) ] × 100 freezing injury rate (%) (young ear freezing injury index of control group-young ear freezing injury index of pesticide application group)/(young ear freezing injury index of 100-control group) × 100

Yield increase (%) (average yield of administration group-average yield of control group)/average yield of control group × 100

Second, experimental results

The results of the field antifreeze management test of wheat are shown in the following table:

group of	Ear freezing injury index (%)	Freezing resistance (%)	Yield increase (%)
				Control group	63.8	-	-
Example 2	41.1	62.7	41.2
				Example 3	45.8	77.3	43.9

According to the report, in 2018, 5-7 days of 4 months, Henan, Shanxi, Shandong, Anhui and the like are subjected to strong cooling weather, and the cooling amplitude reaches about 15 ℃. The air temperature monitoring result of the experimental base is that the lowest air temperature reaches-1 ℃ below zero and the ground lowest temperature is-4 ℃. At the moment, the wheat is growing from the late jointing stage to the booting stage, and the late spring cold inevitably causes the yield reduction of the wheat.

The results show that the young ear freezing injury index of the pesticide application group sprayed in the embodiment 2 or the embodiment 3 before the late spring coldness comes is greatly reduced compared with that of the control group, the pesticide application group shows good freezing resistance compared with the control group, and the yield is increased by more than 40 percent when the pesticide application group is mature and the yield is evaluated. The experiment shows that the spraying of the compound of the invention on wheat in the field before the arrival of cold flow is helpful for wheat frost resistance and increasing the yield, and is a wheat field frost protection management measure which is simple and convenient to operate and easy to popularize.

Obviously, many modifications, substitutions, and variations are possible in light of the above teachings of the invention, without departing from the basic technical spirit of the invention, as defined by the following claims.

Claims

1. A furopyran derivative has a chemical structure of formula (I)

Wherein R is₁、R₂Each independently selected from-H, -CF₃-F or-OCH₃。

2. The furopyran derivative according to claim 1, preferably of the structure:

3. the furopyran derivative according to claim 1, wherein: the synthetic route is as follows:

4. use of the furopyran derivative according to claim 1 in wheat field freeze injury management.