41 results about "2 Butenoic Acids" patented technology

The invention discloses a preparation method for palbociclib (I). The preparation method comprises the following steps: performing cyclization reaction on 2-acetyl-2-butenoic acid methyl ester and malononitrile under an alkaline condition to generate 1,4,5,6-4H-2-methoxyl-4-methyl-5-acetyl-6-oxo-3-pyridine carbonitrile (II); performing substitution reaction on the intermediate (II) and cyclopentane halide (III) under the action of an acid-binding agent to generate N-cyclopentyl-1,4,5,6-4H-2-methoxyl-4-methyl-5-acetyl-6-oxo-3-pyridine carbonitrile (IV); performing condensation reaction on the intermediate (IV) and N-[5-(1-piperazinyl)-2-piperidyl]carbamidine (V)to generate 6-acetyl-8-cyclopentyl-5-methyl-2-[[5-(1-piperazinyl)-2-pyridyl]amino]-5,6-dihydropyrido[2,3-d]pyrimidine-7(8H)-ketone (VI); performing dehydrogenation reaction on the intermediate (VI) and sodium selenate to generate the palbociclib (I). The preparation method for the palbociclib has the advantages that the raw material is easy to obtain, the process is simple, high efficiency and environmental protection are achieved, and the preparation method is suitable for industrial production.

The invention relates to a method for preparing 4-(N-phenothiazine)-carbonyl-2-butenoic acid. The method comprises the following steps: adding A mol of phenothiazine and B mol of maleic anhydride into a reaction container, and then adding acetonitrile; dripping concentrated hydrochloric acid into the reaction container while stirring to get a reaction solution, increasing the temperature of the reaction solution from room temperature to 40-80 DEG C, and performing reaction for 1-2.5h while stirring to get a mixed solution, wherein A: B=2.5: (2.5-3.0); performing reduced-pressure distillation on the mixed solution to remove acetonitrile to get a concentrated solution, wherein the volume of acetonitrile in the concentrated solution is 15-20% of the volume of acetonitrile in the mixed solution; and cooling the concentrated solution to room temperature, then adding water into the concentrated solution, uniformly stirring, then performing suction filtration, washing a filter cake with water, and drying to get 4-(N-phenothiazine)-carbonyl-2-butenoic acid. According to the method disclosed by the invention, acetonitrile is adopted as a solvent, concentrated hydrochloric acid is taken as a catalyst, and the method has the advantages of simplicity and convenience in operation, short reaction time, mild conditions, simple post-treatment, low price and easiness in obtaining of raw materials and high yield.

The invention discloses a method for preparing alkyl 4,4-difluoroacetylacetate. The method has the advantages of easily available raw materials, simple process flow, safety in operation and high yield. The method comprises the following steps: (1) carrying out hydrolysis reaction on 1,1,2,2-tetrafluoroethyl ether used as a raw material and water in an acid and separating to obtain ethyl difluoroacetate and hydrogen fluoride; (2) reacting ethyl difluoroacetate obtained in the step (1) and alkyl acetate in the presence of an alkaline catalyst to obtain 1,1-difluoro-2-butenoic acid alkyl ester-2-hydroxy salt; and (3) neutralizing 1,1-difluoro-2-butenoic acid alkyl ester-2-hydroxy salt obtained in the step (2) and hydrogen fluoride to obtain alkyl 4,4-difluoroacetylacetate.

The invention belongs to the technical field of pesticide intermediates for synthesizing herbicides and particularly relates to a method for synthesizing a pesticide intermediate 2-amido-4-(O-alkylmethylphosphonyl)-2-butenoic acid and its ester. The method comprises that a compound VII and a compound VI undergo an Arbuzov reaction to produce a compound V, the compound V is hydrolyzed through an acid to produce a compound IV, the compound IV and a compound III undergo a reaction under action of a condensation reagent and a catalyst to produce a compound II and the compound II is hydrolyzed into a compound I. Compared with the existing synthesis route, the method has simple processes, high atom economy and high stereoselectivity, is environmentally friendly, realizes a low cost and has an industrial prospect. In the formula, R1 represents C1-4 alkyl; R2 and R3 represent CnH2n+1 and n is 1, 2, 3 or 4, or R2 or R3 represents -CmH2m- and m is 2 or 3; R4 represents C1-4 alkyl or C6-10 aryl; R5 represents hydrogen or C1-4 alkyl; and X represents chlorine or bromine.