52-21-1

Basic information

• Product Name: Prednisolone-21-acetate
• Synonyms: (11beta)-21-(Acetyloxy)-11,17-dihydroxypregna-1,4-diene-3,20-dione;11,17-Dihydroxy-3,20-dioxopregna-1,4-dien-21-yl acetate;11beta,17,21-Trihydroxypregna-1,4-diene-3,20-dione 21-acetate;21-(acetyloxy)-11,17-dihydroxy-4-diene-(11-beta)-pregna-20-dione;21-(acetyloxy)-11,17-dihydroxy-4-diene-(11beta)-pregna-20-dione;4-diene-3,20-dione,11-beta,17,21-trihydroxy-pregna-21-acetate;Ak-Tate;component of Blephamide liquifilm,
• CAS NO: 52-21-1
• Molecular Formula: C₂₃H₃₀O₆
• Molecular Weight: 402.48
• EINECS: 200-134-1
• Product Categories: Biochemistry;Hydroxyketosteroids;Steroids;Intermediates & Fine Chemicals;Pharmaceuticals;API;METICOTOLONE;Applicable to rheumatoid arthritis, rheumatic fever, lupus erythematosus (sle), scleroderma, dermatomyositis, acute lymphocytic leukemia, etc
• Mol File: 52-21-1.mol
• Article Data: 9

Chemical Properties

• Melting Point: 240-244 °C
• Boiling Point: 579.8 °C at 760 mmHg
• Flash Point: 198.4 °C
• Appearance: white crystalline powder
• Density: 1.28 g/cm³
• Vapor Pressure: 7.36E-16mmHg at 25°C
• Refractive Index: 112 ° (C=1, Dioxane)
• Storage Temp.: 2-8°C
• Solubility: Practically insoluble in water, slightly soluble in ethanol (96 per cent) and in methylene chloride.
• PKA: 12.41±0.70(Predicted)
• Water Solubility: 11.6mg/L(25 oC)
• Stability: Stable. Incompatible with strong oxidizing agents.
• Merck: 7721
• BRN: 3111798
• CAS DataBase Reference: Prednisolone-21-acetate(CAS DataBase Reference)
• NIST Chemistry Reference: Prednisolone-21-acetate(52-21-1)
• EPA Substance Registry System: Prednisolone-21-acetate(52-21-1)

Safety Data

• Hazard Codes: T,C,F
• Statements: 25-34-11
• Safety Statements: 45-36/37/39-26-16
• RIDADR: UN 2811 6.1/PG 3
• WGK Germany: 3
• RTECS: TU4152500
• Hazardous Substances Data: 52-21-1(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Industry:
Prednisolone-21-acetate is used as an anti-inflammatory and immunosuppressive agent for the treatment of various conditions, including autoimmune diseases, allergies, and inflammations. Its potent effects make it a valuable component in the development of medications to manage these health issues.
Used in Ophthalmology:
In the field of ophthalmology, Prednisolone-21-acetate is used as a corticosteroid to treat eye inflammations and reduce swelling. Its anti-inflammatory properties help alleviate symptoms and promote healing in ocular conditions.
Used in Dermatology:
Prednisolone-21-acetate is also utilized in dermatology as a topical treatment for various skin conditions, such as eczema, psoriasis, and rashes. Its anti-inflammatory and immunosuppressive actions help reduce redness, itching, and swelling associated with these skin disorders.
Brand names for Prednisolone-21-acetate include Econopred (Alcon), Meticortelone (Schering), Omnipred (Alcon), and Sterane (Pfizer). These products are available in different forms, such as oral tablets, injectable solutions, and topical formulations, catering to the specific needs of patients and healthcare providers.

Originator

Sterane, Phipharmex ,US ,1955

Manufacturing Process

To a solution of 0.85 gram of 1,4-pregnadiene-11β,17α,21-triol-3,20-dione (prednisolone) in 5 ml of pyridine are added 3 ml of acetic anhydride. The reaction mixture is allowed to stand at room temperature overnight and is then diluted with ice water. The resulting precipitate is filtered from the mixture and recrystallized from acetone-hexane. There is recovered 0.45 gram of 1,4-pregnadiene-11β,17α,21-triol-3,20-dione 21-acetate, MP 235°239°C. On recrystallization, the MP rose to 237°-239°C.

Therapeutic Function

Glucocorticoid

Biological Activity

Prednisolone Acetate (Omnipred) is a synthetic corticosteroid that is a particularly potent immunosuppressant.

Clinical Use

For rheumatoid arthritis, rheumatic fever, lupus erythematosus, scleroderma, dermatomyositis, acute lymphoblastic leukemia, etc.

Purification Methods

Recrystallise prednisolone acetate from EtOH, Me2CO, Me2CO/hexane, and it has UV with max at 243nm in EtOH. [Joly et al. Bull Soc Chim Fr 366 1958; Herzog et al. J Am Chem Soc 77 4781 1955, Beilstein 8 IV 3468.]

InChI:InChI=1/C23H30O6/c1-13(24)29-12-19(27)23(28)9-7-17-16-5-4-14-10-15(25)6-8-21(14,2)20(16)18(26)11-22(17,23)3/h6,8,10,16-18,20,26,28H,4-5,7,9,11-12H2,1-3H3/t16?,17?,18-,20?,21?,22-,23-/m0/s1

Synthetic route

prednisolon (50-24-8) + acetic anhydride (108-24-7) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
With dmap In N,N-dimethyl-formamide at 40℃; for 0.5h; Inert atmosphere;	99.8%
With pyridine	98%
With pyridine
With dmap at 60 - 65℃; for 6h; Time;	55.1 g
With sodium acetate In tetrahydrofuran; acetone at 40℃; for 3h; Reagent/catalyst; Inert atmosphere;

21-acetoxy-9-bromo-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione (4224-31-1) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
Stage #1: 21-acetoxy-9-bromo-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione With chromium(VI) oxide; mercaptoacetic acid; zinc In dimethyl sulfoxide; acetone at 15 - 20℃; Stage #2: With hydrogenchloride In water for 1h; Stage #3: With sodium thiosulfate In water for 0.333333h; Reagent/catalyst;	92%

hydrocortisone acetate (50-03-3) → prednisolone 21-acetate (52-21-1) + 21,21'-diacetoxy-11β,17,11'β,17'-tetrahydroxy-2,2'-diselanediyl-bis-pregna-1,4-diene-3,20-dione (120612-05-7)

Conditions	Yield
With selenium(IV) oxide; acetic acid

21-acetoxy-11β-hydroxy-pregna-1,4,17(20)c-trien-3-one (28449-43-6) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
With [bis(acetoxy)iodo]benzene

21-acetoxy-1117β-dihydroxy-pregn-4-en-3,20-one → prednisolone 21-acetate (52-21-1)

Conditions	Yield
With selenium(IV) oxide
With iodine pentoxide

21-acetoxy-2α,4β-dibromo-11β,17-dihydroxy-5pregnane-3,20-dione → prednisolone 21-acetate (52-21-1)

Conditions	Yield
With lithium carbonate; N,N-dimethyl-formamide; lithium bromide

21-acetoxy-9-chloro-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione (24916-88-9) → prednisolone 21-acetate (52-21-1)

oxone + 11β,17α-dihydroxy-20-phenoxypregna-1,4,20-trien-3-one + Oxone + ethylene glycol (107-21-1) → prednisolon (50-24-8) + prednisolone 21-acetate (52-21-1)

Conditions	Yield
With potassium hydroxide; sodium hydroxide In tetrahydrofuran; PO4; dichloromethane; water; acetone

oxone + 11β,17α-dihydroxy-20-phenoxypregna-1,4,20-trien-3-one + Oxone → prednisolone 21-acetate (52-21-1)

Conditions	Yield
With dmap; potassium hydroxide; sodium hydroxide; acetic anhydride; triethylamine In tetrahydrofuran; PO4; dichloromethane; water; acetone
With dmap; potassium hydroxide; sodium hydroxide; acetic anhydride; triethylamine In tetrahydrofuran; PO4; n-heptane; dichloromethane; water; acetone

21-acetoxy-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione disemicarbazone (96580-08-4) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
Stage #1: 21-acetoxy-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione disemicarbazone With hydrogenchloride In chloroform; water at 25 - 30℃; for 0.5h; Stage #2: With sodium nitrite In chloroform; water at 18 - 22℃; for 6h;	19.5 g

prednisone acetate (125-10-0) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
Stage #1: prednisone acetate With sodium acetate; acetic anhydride; acetic acid In acetone for 4h; Reflux; Stage #2: With hydrogenchloride In chloroform; water at 25 - 30℃; for 0.5h; Stage #3: With sodium nitrite In chloroform; water at 18 - 22℃; for 3h; Reagent/catalyst;	21.8 g

pregna-1,4,9(11)-triene-17α,21-diol-3,20-dione 21-acetate (4380-55-6) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: sulfuric acid / acetone; water / 0.5 h / 0 - 5 °C 1.2: 0 - 5 °C 2.1: zinc; chromium(VI) oxide; mercaptoacetic acid / acetone; dimethyl sulfoxide / 15 - 20 °C 2.2: 1 h 2.3: 0.33 h View Scheme

(10S,13S,17R)-17-hydroxy-17-(2-hydroxyacetyl)-10,13-dimethyl-6,7,8,10,12,13,14,15,16,17-decahydro-3H-cyclopenta[a]phenanthren-3-one (10184-69-7) → prednisolone 21-acetate (52-21-1)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: dmap / chloroform / 0.17 h 1.2: 10 - 20 °C 2.1: sulfuric acid / acetone; water / 0.5 h / 0 - 5 °C 2.2: 0 - 5 °C 3.1: zinc; chromium(VI) oxide; mercaptoacetic acid / acetone; dimethyl sulfoxide / 15 - 20 °C 3.2: 1 h 3.3: 0.33 h View Scheme

methanol (67-56-1) + prednisolone 21-acetate (52-21-1) → prednisolon (50-24-8) + acetic acid methyl ester (79-20-9)

Conditions	Yield
With triethylamine at 20℃; under 8250660 Torr; for 2h; Product distribution;	A n/a B 100%

prednisolone 21-acetate (52-21-1) → prednisone acetate (125-10-0)

Conditions	Yield
With 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione In N,N-dimethyl-formamide at 23 - 25℃; for 5h;	99%
With 1-hydroxy-1.oxo-1H-1λ5-benzo[d][1,2]iodoxol-3-one pyridinium salt In N,N-dimethyl-formamide at 24 - 28℃; for 4h;	97%
With N-bromoacetamide
With chromium(VI) oxide

prednisolone 21-acetate (52-21-1) → prednisolon (50-24-8)

Conditions	Yield
With water; potassium carbonate; sodium hydroxide In methanol at 0 - 10℃; for 2h; Inert atmosphere;	92.5%
With methanol; triethylamine for 14h; Ambient temperature;	49%
With potassium hydroxide
Stage #1: prednisolone 21-acetate With water; sodium hydroxide In methanol; dichloromethane at 0 - 30℃; for 2.5h; Inert atmosphere; Stage #2: With acetic acid In methanol; dichloromethane at -12 - -5℃; for 1h; pH=6 - 7; Reagent/catalyst; Reflux;	15.8 g

prednisolone 21-acetate (52-21-1) → 2-((10S,13S,14S)-10,13-dimethyl-3-oxo-6,7,8,10,12,13,14,15-octahydro-3H-cyclopenta[a]phenanthren-17-yl)-2-oxoethyl acetate (37413-91-5)

Conditions	Yield
Stage #1: prednisolone 21-acetate With pyridine; N-chloro-succinimide at -15 - 20℃; for 0.416667h; Inert atmosphere; Stage #2: With sulfur dioxide for 1h; Inert atmosphere;	83.5%

prednisolone 21-acetate (52-21-1) → lumiprednisolone 21-acetate (73454-02-1)

Conditions	Yield
In 1,4-dioxane for 3.5h; Irradiation;	78%

prednisolone 21-acetate (52-21-1) → 2-((10S,13S,14S)-10,13-dimethyl-3-oxo-6,7,8,10,12,13,14,15-octahydro-3H-cyclopenta[a]phenanthren-17-yl)-2-oxoethyl acetate (37413-91-5) + pregna-1,4,9(11)-triene-17α,21-diol-3,20-dione 21-acetate (4380-55-6) + 2-((10S)-10,17-dimethyl-3-oxo-6,7,8,10,12,15,16,17-octahydro-3H-cyclopenta[a]phenanthren-17-yl)-2-oxoethyl acetate + C46H54O11S

Conditions	Yield
With pyridine; thionyl chloride In N,N-dimethyl-formamide at 20℃; Reagent/catalyst; Temperature;	A 50% B n/a C n/a D n/a

prednisolone 21-acetate (52-21-1) → pregna-1,4,9(11)-triene-17α,21-diol-3,20-dione 21-acetate (4380-55-6)

Conditions	Yield
With N,N'-Thionyldiimidazole In tetrahydrofuran for 0.5h; Ambient temperature;	41%
With pyridine; methanesulfonyl chloride

prednisolone 21-acetate (52-21-1) → Acetic acid 2-oxo-2-((3R,3aS,5S,5aR,6S,6aR,11aS,11bS)-3,5,6-trihydroxy-3a,6-dimethyl-8-oxo-2,3,3a,4,5,5a,6,6a,7,8,10,11,11a,11b-tetradecahydro-1H-indeno[5,4-f]azulen-3-yl)-ethyl ester (73398-00-2) + Acetic acid 2-((3aS,4aS,5aS,6R,8aS,8bS,10bS,10cS)-6-hydroxy-5a,10b-dimethyl-3-oxo-3,3a,4a,5,5a,6,7,8,8a,8b,9,10,10b,10c-tetradecahydro-2H-4-oxa-dicyclopenta[a,def]phenanthren-6-yl)-2-oxo-ethyl ester (73398-10-4) + C23H32O7 (73398-05-7)

Conditions	Yield
In acetic acid for 2.5h; Irradiation;	A 20.1% B 38.5% C 19.2%

prednisolone 21-acetate (52-21-1) → Acetic acid 2-oxo-2-((6S,8S,9S,10R,11S,13S,14S,17R)-6,11,17-trihydroxy-10,13-dimethyl-3-oxo-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-yl)-ethyl ester (134526-05-9)

Conditions	Yield
With selenium(IV) oxide In 1,4-dioxane at 110℃; for 28h;	21.5%

diazomethane (186581-53-3, 908094-01-9) + prednisolone 21-acetate (52-21-1) → 20,21-epoxy-11β,17,22-trihydroxy-23,24-dinor-20ξH-chola-1,4-dien-3-one (102958-04-3)

Conditions	Yield
With methanol; diethyl ether

prednisolone 21-acetate (52-21-1) → 21-acetoxy-11β,17-dihydroxy-pregna-1,5-diene-3,20-dione (112441-85-7)

Conditions	Yield
With 1,4-dioxane; bromine; acetic acid Erwaermen des Reaktionsprodukts mit Zink und wss.Aethanol;

prednisolone 21-acetate (52-21-1) → 21-acetoxy-1α,5-disulfanediyl-11β,17-dihydroxy-5α-pregnane-3,20-dione (115231-00-0)

Conditions	Yield
With pyridine; hydrogen sulfide; sulfur

prednisolone 21-acetate (52-21-1) + triethyl phosphite (122-52-1) → O21-Acetyl-1-diaethoxyphosphinyl-hydrocortisol (14413-10-6)

Conditions	Yield
With phenol

prednisolone 21-acetate (52-21-1) → (8S,9S,10R,11S,13S,14S)-11-Hydroxy-10,13-dimethyl-7,8,9,10,11,12,13,14,15,16-decahydro-6H-cyclopenta[a]phenanthrene-3,17-dione (898-84-0) + prednisone acetate (125-10-0)

Conditions	Yield
Product distribution; Rate constant; Irradiation; radiolytic degradation;

prednisolone 21-acetate (52-21-1) → (20R)-21-acetoxy-11β,17,20-trihydroxy-3-oxo-1,4-pregnadiene (96346-38-2)

Conditions	Yield
With sodium tetrahydroborate In N,N-dimethyl-formamide for 3h; Ambient temperature;	235 mg

prednisolone 21-acetate (52-21-1) → Acetic acid 2-((8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-10,13-dimethyl-3-thioxo-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-yl)-2-oxo-ethyl ester (71826-43-2)

Conditions	Yield
With pyridine; tetraphosphorus decasulfide

prednisolone 21-acetate (52-21-1) → 11α-Hydroxy-1-methoxy-4-methyl-oestra-1,3,5(10)-trien-17-on

Conditions	Yield
Multistep reaction;

prednisolone 21-acetate (52-21-1) + acetic anhydride (108-24-7) → 11β-Acetoxy-1.17.21-trihydroxy-4-methyl-19-nor-pregna-1.3.5(10)-trien-20-on (53771-09-8)

Conditions	Yield
(i) aq. HClO4, (ii) NaOMe, aq. AcOH; Multistep reaction;

prednisolone 21-acetate (52-21-1) + acetic anhydride (108-24-7) → 1.11β.17.21-Tetraacetoxy-4-methyl-19-nor-pregna-1.3.5(10)-trien-20-on

Conditions	Yield
With perchloric acid

prednisolone 21-acetate (52-21-1) → 21-acetoxy-17-hydroxy-5,11-dioxo-de-A-pregnane-10aα-carbaldehyde (102378-22-3)

Conditions	Yield
(i) O3, AcOEt, (ii) H2O; Multistep reaction;

prednisolone 21-acetate (52-21-1) → 4α,5α,11β,17α,21-Pentahydroxy-pregn-1-en-3,20-dion-21-acetat (1178-19-4)

Conditions	Yield
(i) OsO4, Py, (ii) H2S, dioxane, CHCl3; Multistep reaction;

prednisolone 21-acetate (52-21-1) → Acetic acid 2-{(1R,3aS,4S,5S,6aS)-5-formyl-1-hydroxy-4-[2-(5-hydroxy-2-methyl-phenyl)-ethyl]-6a-methyl-octahydro-pentalen-1-yl}-2-oxo-ethyl ester

Conditions	Yield
(i) POCl3, THF, (ii) (enzymatic hydrolysis); Multistep reaction;

prednisolone 21-acetate (52-21-1) → Phosphoric acid mono-(3-{2-[(1S,2S,3aS,4R,6aS)-2-formyl-4-hydroxy-4-(2-hydroxy-acetyl)-3a-methyl-octahydro-pentalen-1-yl]-ethyl}-4-methyl-phenyl) ester

Conditions	Yield
(i) POCl3, THF, (ii) aq. K2CO3, MeOH; Multistep reaction;

prednisolone 21-acetate (52-21-1) → 1α.2α.11β.17α.21-Pentahydroxy-pregn-4-en-3.20-dion-21-acetat (1255-33-0)

Conditions	Yield
(i) OsO4, Py, (ii) H2S, dioxane, CHCl3; Multistep reaction;

prednisolone 21-acetate (52-21-1) → Acetic acid 2-{(1R,3aS,4S,5S,6aS)-5-formyl-1-hydroxy-6a-methyl-4-[2-(2-methyl-5-phosphonooxy-phenyl)-ethyl]-octahydro-pentalen-1-yl}-2-oxo-ethyl ester

Conditions	Yield
(i) POCl3, THF, (ii) aq. NaOH, MeOH; Multistep reaction;

Upstream product

• 28449-43-6 21-acetoxy-11β-hydroxy-pregna-1,4,17(20)c-trien-3-one 
• 10184-69-7 (10S,13S,17R)-17-hydroxy-17-(2-hydroxyacetyl)-10,13-dimethyl-6,7,8,10,12,13,14,15,16,17-decahydro-3H-cyclopenta[a]phenanthren-3-one 
• 4380-55-6 pregna-1,4,9(11)-triene-17α,21-diol-3,20-dione 21-acetate 
• 4224-31-1 21-acetoxy-9-bromo-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione 
• 125-10-0 prednisone acetate 
• 96580-08-4 21-acetoxy-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione disemicarbazone 
• 107-21-1 ethylene glycol 
• 24916-88-9 21-acetoxy-9-chloro-11β,17-dihydroxy-pregna-1,4-diene-3,20-dione 
• 50-24-8 prednisolon 
• 108-24-7 acetic anhydride 
• 50-03-3 hydrocortisone acetate 

Downstream Products

• 898-84-0 (8S,9S,10R,11S,13S,14S)-11-Hydroxy-10,13-dimethyl-7,8,9,10,11,12,13,14,15,16-decahydro-6H-cyclopenta[a]phenanthrene-3,17-dione 
• 125-10-0 prednisone acetate 
• 134526-05-9 Acetic acid 2-oxo-2-((6S,8S,9S,10R,11S,13S,14S,17R)-6,11,17-trihydroxy-10,13-dimethyl-3-oxo-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthren-17-yl)-ethyl ester 
• 96346-38-2 (20R)-21-acetoxy-11β,17,20-trihydroxy-3-oxo-1,4-pregnadiene 
• 50-24-8 prednisolon 
• 79-20-9 acetic acid methyl ester 
• 71826-53-4 Acetic acid 2-[(8S,9S,10R,11S,13S,14S,17R)-11,17-dihydroxy-10,13-dimethyl-3-(2-nitro-phenyldisulfanyl)-8,9,10,11,12,13,14,15,16,17-decahydro-7H-cyclopenta[a]phenanthren-17-yl]-2-oxo-ethyl ester 
• 2871-71-8 21-acetoxy-11β,17α,20α-trihydroxy 1,4-pregnadiene-3-one 
• 37413-91-5 2-((10S,13S,14S)-10,13-dimethyl-3-oxo-6,7,8,10,12,13,14,15-octahydro-3H-cyclopenta[a]phenanthren-17-yl)-2-oxoethyl acetate 
• 3044-42-6 21-acetoxy-11β-hydroxyl-1,4,16-pregnatriene-3,20-dione 
• 51372-29-3 budesonide 
• 13951-70-7 desonide 
• 4380-55-6 pregna-1,4,9(11)-triene-17α,21-diol-3,20-dione 21-acetate 
• 53770-95-9 (1S,2S,3aS,4R,6aS)-4-Hydroxy-4-(2-hydroxy-acetyl)-1-[2-(5-hydroxy-2-methyl-phenyl)-ethyl]-3a-methyl-octahydro-pentalene-2-carbaldehyde 

Relevant articles and documents

Preparation method of prednisolone acetate

The invention relates to prednisolone acetate and a preparation method of prednisolone acetate, which are characterized in that the prednisolone acetate is prepared by sequentially carrying out a biological fermentation, an esterification reaction, a bromination reaction and a debromination reaction on the raw material, the prednisolone acetate is subjected to a hydrolysis reaction to obtain prednisolone, the overall yield is up to 81.75%, and the HPLC area normalization content of prednisolone is up to 99.5%. The preparation method is short in synthetic route and low in cost, is suitable forindustrial production, and has a very high industrial value.

Preparation method of tetraene acetate

The invention discloses a preparation method of tetraene acetate. The preparation method of tetraene acetate comprises a step of subjecting a compound 2 as described in the specification, a free radical type halogenating reagent, sulfur dioxide and an acid-binding agent to a reaction in an organic solvent so as to obtain a compound 1 as described in the specification, i.e., tetraene acetate. According to the preparation method, easily and commercially available prednisolone low in price is used as a starting raw material, hydroxyl groups of two different configurations are simultaneously eliminated in the one-step reaction, and intracyclic alkene is formed; and the method is reduced in reaction steps, mild in reaction conditions, simple in aftertreatment, high in yield, high in the chemical purity of a crude product and suitable for industrial production.

Optimization of the synthesis of a key intermediate for the preparation of glucocorticoids

A short and efficient synthesis, based on a one-step double elimination, of a key intermediate in the synthesis of various glucocorticosteroids has been developed. This method can be carried out on large scale for further industrial applications. The synthesis allowed us to identify a novel prednisolone derivative 10 and its anti-inflammatory activity was determined in an in vivo model of inflammation. In order to understand the regioselectivity of the double elimination under various conditions, mechanistic studies were undertaken and confirmed the experimental results. We also propose a mechanism for the formation of the new steroid 10 studied by molecular modeling.

C21 steroid 21 site acetylation process

The invention discloses a C21 steroid 21 site acetylation process. C21 steroid is prednisolone, hydrocortisone, dexamethasone or betamethasone; the C21 steroid is subjected to acetylation with aceticanhydride; the acetylation of the C21 steroid with the acetic anhydride is carried out in a mixed solvent; an acetic acid alkali metal salt is adopted as a catalyst, and the reaction is carried out inthe presence of an inert gas; the mixed solvent is a mixed solvent of tetrahydrofuran and acetone; the weight ratio of the tetrahydrofuran to the acetone in the mixed solvent is (2-9):1. High-toxicity and high ammonia nitrogen pyridine and dimethylformamide are replaced by using the mixed solvent of tetrahydrofuran and acetone without ammonia nitrogen, no high ammonia nitrogen wastewater is generated, and environment pollution can be reduced.

Preparation process of prednisolone acetate

The invention relates to a preparation process of prednisolone acetate. The preparation process comprises the steps that under the action of 4-dimethylamino-pyridine, no solvent needs to be additionally added, prednisolone and acetic anhydride directly react, the materials are flushed into water for separation, filtering and drying are carried out, and prednisolone acetate is prepared. The technical prejudice that in the prior art of the reaction process, pyridine or a pyridine-substituted solvent is generally used is overcome, the lot production capacity of a reaction still is greatly improved, and it is avoided that a large amount of industrial waste water hard to treat is generated. The process is simple in process, beneficial to environmental protection, low in cost and suitable for industrial large-scale production.

A process for the preparation of prednisolone (by machine translation)

The invention relates to a process for the preparation of prednisolone, including: to ACOH predinisone as raw materials, sequentially through the 3,20-keto-protection reaction and 11-keto-reduction reaction, 21-position hydroxy esterification reaction, 3,20- position alkone remove protection reaction, 21-bit b ester hydrolysis reaction is prednisolone. The present invention provides a first esterification, then deprotected of the new synthetic route, the deprotected process the nitrosation quenching reaction and resin hydrolysis reaction; an ester reaction in the mixed solvent and to complete the protection of inert gas, to avoid the hydrolysis reaction produces by-products. Process route of this invention is novel, the operation process is simple, the production cost is low, is suitable for industrial scale production. (by machine translation)

Prednisolone acetate preparation method

The present invention relates to a prednisolone acetate preparation method which is as follows: prednisolone acetate can be obtained by successive 3-site and 20-site keto-protection reaction, 11-site keto-reduction reaction, 21-site hydroxyl esterification reaction and 3-site and 20-site keto-deprotection reaction of prednisone acetate as a raw material. A new synthetic route of first esterification and then deprotection is provided, nitrosification quenching reaction and resin hydrolysis reaction can be omitted in the deprotection step, the technical process is greatly simplified, the cost of production is reduced, and the method is suitable for mass production.

9α-dehalogenation process

The present invention involves improved processes for the dehalogenation of 9α-halosteroids (I) STR1 to produce the corresponding 11β-hydroxy steroids (II) STR2 which are known to be useful as pharmaceutical, where the improvements comprise (1) adding the 9α-halo steroid (I) to the chromium and (2) using catalytic amounts of chromium in the presence of a means of converting chromium (II) to chromium (III).

Process and intermediates for the preparation of 17 alphahydroxyprogesterones and corticoids from an enol steroid

This invention discloses an improved process for the production of corticoids from 17α-hydroxy steroids utilizing peroxymonosulfate.