- Preparation methods for 5-aminolevulinic acid hydrochloride and 5-aminolevulinic acid hydrochloride intermediate
-
The invention discloses preparation methods for a 5-aminolevulinic acid hydrochloride and a 5-aminolevulinic acid hydrochloride intermediate. The preparation method for the 5-aminolevulinic acid hydrochloride intermediate comprises: (1) carrying out a reaction on a compound 2 and isopropylidene malonate in an organic solvent under the actions of an organic alkali and a condensing agent to obtain acompound 3; and (2) carrying out a reaction on the compound 3 in a C1-C4 alcohol solvent to obtain a compound 4, wherein R1 and R' are respectively and independently C1-C4 alkyl. The present invention further provides a method for preparing a 5-aminolevulinic acid hydrochloride by using the 5-aminolevulinic acid hydrochloride intermediate. According to the present invention, the intermediate product is basically solid and is easily crystallized and purified; and the method has characteristics of high yield, low production cost and easy operation, and is suitable for industrial production. Thecompounds 1, 2, 3 and 4 are defined in the specification.
- -
-
Paragraph 0075; 0076; 0078; 0095
(2018/09/11)
-
- PYRIMIDINE COMPOUNDS CONTAINING ACIDIC GROUPS
-
The present disclosure relates to a class of pyrimidine derivatives having immunomodulating properties that act via TLR7 which are useful in the treatment of viral infections and cancers.
- -
-
Paragraph 1170; 1171
(2018/06/15)
-
- BENZOXAZEPINE COMPOUND
-
A compound represented by the formula [1]: wherein ring A and ring B each represent an optionally substituted benzene ring; ring C represents an optionally further substituted aromatic ring; R1 represents a lower alkyl group optionally substituted with an optionally substituted hydroxyl group; X1a represents a bond or optionally substituted lower alkylene; X1b represents a bond or optionally substituted lower alkylene; X2 represents a bond, -O- or -S-; X3 represents a bond or an optionally substituted divalent hydrocarbon group; Y represents an optionally esterified or amidated carboxyl group, or a salt thereof. The compound of the formula [I] is safer and has more potent lipid lowering activity such as squalene synthase inhibitory activity (cholesterol lowering activity) and triglyceride lowering activity, and thus it is a compound useful as an agent for preventing or treating hyperlipemia.
- -
-
Page/Page column 26-27
(2010/11/08)
-
- The reactions of diazo compounds with lactones. Part 1. Cyclopropanespiro-β-lactones from diketene: Synthesis and reactions
-
The cyclopropanespiro-β-lactones 3, 4 and 12 can be prepared by the metal catalysed, or photochemically promoted decomposition reactions of diazocompounds in the presence of diketene. The thermal reactions of these compounds give a variety of products depending on the nature of the spirolactone; these include a furan 9a, 1,4-dicarbonyl compounds 18a-c and 19b, a pyranone 20b, furanones 21a, 21f and 22a and the enol 16. The boron trifluoride promoted reaction of a mixture of 3b and 4b gives a 13-ketoacid. Mechanisms are proposed for the formation of these products. The rearrangment of the cyclopropanespiro-β-lactones to furan-2(5H)-ones and furan-2-(3H)-ones 6-8, 21a, 21f, 22a and 24 is shown to be a general reaction that involves metal catalysis. A mechanism based on formation of a metallocycle by a novel insertion of the metal into the C-O bond of the β-lactone ring is proposed for this rearrangement. This accounts for the observed features of the reaction.
- Murphy, Paul V.,O'Sullivan, Timothy J.,Geraghty, Niall W.A.
-
p. 2109 - 2119
(2007/10/03)
-
- Niobium pentachloride-mediated novel homologation reactions using α-trialkylstannylmethyl-β-keto esters
-
In the presence of niobium pentachloride (NbCl5), an α-trialkylstannylmethyl-β-keto ester is homologated to the corresponding γ-keto ester in good yield; the reaction mechanism is discussed.
- Yamamoto, Makoto,Nakazawa, Misako,Kishikawa, Keiki,Kohmoto, Shigeo
-
p. 2353 - 2354
(2007/10/03)
-
- Metal catalysed rearrangement of cyclopropanespiro-β-lactones to 2-furanones
-
The rearrangement of 5-oxo-4-oxaspiro[2.3]hexanes (cyclopropanespiro-β-lactones) to 2(5H)-furanones and 2(3H)-furanones is shown to be a general reaction which is promoted by metal catalysts. A mechanism is proposed, involving the novel insertion of a metal species into the O-C(β) bond of the β-lactone ring, which explains the basic features of the reaction, including its regioselectivity.
- Geraghty, Niall W. A.,Murphy, Paul A.
-
p. 6737 - 6740
(2007/10/02)
-
- Preparation of γ-Substituted β-Oxoesters with a New Heterocyclic Synthon
-
Ethyl 2,5-dihydro-2,3-dimethyl-5-oxoisoxazole-4-carboxylate was alkylated and acylated via its potassium-salt generated by potassium t-butoxide under convenient conditions.Hydrolysis of the enamines obtained by the catalytic hydrogenation of the 3-alkylated/acetylated derivatives affords β-oxo and β,δ-dioxoesters, respectively.Hydrogenolysis of the 3-acyl derivatives allows the regiospecific synthesis of β-enamino-δ-oxoesters.
- Doleschall, Gabor,Seres, Peter,Kovacs, Attila
-
p. 324 - 346
(2007/10/02)
-
- A NEW ENAMINE-SALT FOR THE SYNTHESIS OF γ-ALKYLATED ETHYL ACETOACETATE DERIVATIVES
-
A convenient method for the preparation of γ-alkylated ethyl acetoacetate from alkyl halides via a new isoxazole enamine-salts is reported.
- Doleschall, G.
-
p. 6339 - 6340
(2007/10/02)
-
- AN IMPROVED SYNTHESIS OF 2-METHYL-4-(2'-CARBOXYETHYL)PYRROLE. POTENTIAL INHIBITORS OF PORPHOBILINOGEN DEAMINASE
-
Improved syntheses of 2-methyl-4-(2'-carboxyethyl)pyrrole (10) (49percent overall yield) and of several O- and S-containing β-(5-ring heterocyclic)-substituted propionic acid are described.Some of these compounds have been found to be inhibitors of porphobilinogen deaminase.
- Wilen, Samuel H.,Shen, DeKang,Licata, Joseph M.,Baldwin, Enoch,Russell, Charlotte S.
-
p. 1747 - 1757
(2007/10/02)
-
- Some Reactions of Enol-Lactones with Metal Alkoxides
-
The reactions of various alkyl 5-oxo-2,5-dihydrofuran-2-ylideneacetates and related enol-lactones with sodium alkoxides in alcohols have been studied.Four types of compounds have been characterized, each as the major product, depending on the concentration of alkoxide, the reaction time and the temperature. 4-Methylcyclopentene-1,3-dione and 4,5-dimethylcyclopentene-1,3-dione have been prepared by short syntheses.
- Massy-Westropp, Ralph A.,Price, Martyn F.
-
p. 2369 - 2383
(2007/10/02)
-
- 2,3,5,6-Tetracarboxy-1,4-dihydropyridine derivatives
-
1,4-Dihydropyridines bearing carboxy functions in the 3-, 5- and 6- or 2-, 3-, 5- and 6-positions and being substituted in the 4-position by phenyl, substituted phenyl, naphthyl, phenylalkyl or a heterocyclic group are antihypertensive agents and coronary vessel dilators. The compounds, of which 2-methyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5,6-tricarboxylic acid triethylester is a representative embodiment, are prepared through condensation of an enamine with an ylidene acid ester, the latter being separately prepared or prepared in situ.
- -
-
-
- 1,4-Dihydropyridine esters
-
A new class of 1,4-dihydropyridines which are characterized by the presence of ester substitutes at positions 3 and 5 of the nucleus and by the presence of an alkoxyalkyl at position 2. The products exhibit coronary activity and have particular application as coronary dilators, antifibrillators, anti-hypertensives, and as muscular and vascular spasmolytics.
- -
-
-