CAS 138421-23-5

Acetone O-isobutyryloxime

Codes: Molnupiravir-010

Application context (from source-drug indications)

COVID-19Molnupiravir呼吸道合胞体病毒感染MolnupiravirInfluenza virus infectionMolnupiravirRenal impairmentMolnupiravirHepatic function declineMolnupiravir

Source drugs (routes using this intermediate)

Drug	Tier	Expiry
Molnupiravir	Tier B — Position early	-

Position in synthesis routes (up/downstream chain)

Ordered by route registration; left → right is the synthesis direction. The highlighted node is the current CAS; others link to their own profiles.

MolnupiravirOriginator routesteps: 10total yield: /

1-(beta-D-Ribofuranosyl)uracil→1-[(3aR,4R,6R,6aR)-6-(Hydroxymethyl)-2,2-dimethyl-tetrahydro-2H-furo[3,4-d][1,3]dioxol-4-yl]-1,2,3,4-tetrahydropyrimidine-2,4-dione<-fgf->2',3'-O-Isopropylideneuridine→2-Methylpropionic anhydride→2',3'-O-(1-Methylethylidene)-5'-O-(2-methylpropanoyl)uridine→N-Hydroxy-2',3'-O-(1-methylethylidene)-5'-O-(2-methylpropanoyl)cytidine→1H-1,2,4-Triazole→1-[2,3-O-(1-Methylethylidene)-5-O-(2-methylpropanoyl)-beta-D-ribofuranosyl]-4-(1H-1,2,4-triazol-1-yl)pyrimidin-2(1H)-one→1-beta-D-Ribofuranosyl-4-(1H-1,2,4-triazol-1-yl)-3,4-dihydropyrimidin-2(1H)-one→1-[2,3-O-(1-Methylethylidene)-beta-D-ribofuranosyl]-4-(1H-1,2,4-triazol-1-yl)pyrimidin-2(1H)-one→Acetone O-isobutyryloxime→1-[(2xi)-5-O-(2-Methylpropanoyl)-beta-D-erythro-pentofuranosyl]-4-(1H-1,2,4-triazol-1-yl)-3,4-dihydropyrimidin-2(1H)-one

MolnupiravirOptimised routesteps: 11total yield: /

Acetone oxime→2',3'-O-(1-Methylethylidene)-5'-O-(2-methylpropanoyl)cytidine→5'-O-Isobutyryl cytidine→Acetone→2-Methylpropionic acid→Sulfuric acid 2',3'-O-(1-methylethylidene)cytidine→Isobutyric anhydride→1-(beta-D-Ribofuranosyl)cytosine→Acetone O-isobutyryloxime→N-Hydroxy-2',3'-O-(1-methylethylidene)-5'-O-(2-methylpropanoyl)cytidine

MolnupiravirOptimised routesteps: 8total yield: 77.1g(Molnupiravir)

N4-Hydroxycytidine→2-Methylpropyl 2-methylpropanoate→Ethenyl 2-methylpropanoate→1-(beta-D-Ribofuranosyl)cytosine→Acetone O-isobutyryloxime→2-Methylpropionyl chloride→5'-O-Isobutyryl cytidine→2-Methylpropionic anhydride

MolnupiravirOptimised routesteps: 2total yield: /

Acetone O-isobutyryloxime→2-Methylpropionyl chloride→2-Methylpropionic acid→2-Propanone→N-Hydroxypropan-2-imine

MolnupiravirOptimised routesteps: 7total yield: 30.72g(Molnupiravir)

N-Hydroxy-2',3'-O-(1-methylethylidene)cytidine→2,2,2-Trifluoroethyl 2-methylpropanoate→1-[(3aR,4R,6R,6aR)-6-(Hydroxymethyl)-2,2-dimethyl-tetrahydro-2H-furo[3,4-d][1,3]dioxol-4-yl]-1,2,3,4-tetrahydropyrimidine-2,4-dione<-fgf->2',3'-O-Isopropylideneuridine→Hydroxylammonium chloride→Acetone O-isobutyryloxime→Ethenyl 2-methylpropanoate→N-Hydroxy-2',3'-O-(1-methylethylidene)-5'-O-(2-methylpropanoyl)cytidine→2',3'-O-(1-Methylethylidene)-5'-O-(2-methylpropanoyl)uridine

MolnupiravirOptimised routesteps: 6total yield: 5.14g(Molnupiravir)

N-[(Dimethylamino)methylidene]cytidine→5'-O-(2-Methylpropanoyl)cytidine oxalate→N,O2',O3'-Tris[(dimethylamino)methylidene]cytidine→1-(beta-D-Ribofuranosyl)cytosine→Acetone O-isobutyryloxime→Isobutyryl chloride→2-Methylpropionic acid→5'-O-Isobutyryl cytidine→Dimethylacetic anhydride

Intermediates available on this site

Side-by-side comparison of all listed offers on this CAS; price bands are list-price ranges, final price subject to RFQ confirmation.

Supplier	Product	Price band	MOQ	Lead time	Qualifications	Action
Unibest Taizhou GMP-like Site	((3aR,4R,6R,6aR)-6-(4-(hydroxyamino)-2-oxopyrimidin-1(2H)-yl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methyl isobutyrate Pharmaceutical Intermediates	On request	On request	On request	—

This is a CAS-level registry record: registrations across routes are merged. Supplier offers and buyer demands will be matched on this CAS as the primary key.