HuagongsheHuagongshe Chemistry Print Report · For research reference only
p-Toluenesulfonic acid → 6-Bromo-2H-1-benzopyran-3(4H)-one
Participants
| Role | Name | HCID | Charge |
|---|---|---|---|
| Reactant | p-Toluenesulfonic acid | HCID 6101 | — |
| Reactant | Methyl morpholine oxide | HCID 82029 | — |
| Reactant | 6-bromo-3,4-dihydro-2H-1-benzopyran-4-one | HCID 4197451 | — |
| Reactant | Sodium borohydride | HCID 4311764 | — |
| Reactant | 6-bromo-2H-chromene | HCID 10242241 | — |
| Catalyst | Osmium Tetroxide | HCID 30318 | — |
| Solvent | Acetone tBuOH Water | HCID 86602953 | — |
| Product | 6-Bromo-2H-1-benzopyran-3(4H)-one | HCID 58466622 | — |
Reaction Steps
The starting material 6-bromochroman-3-one (5A) was prepared from 6-bromochroman-4-one in a manner similar to that described in the literature (Synthesis, 1980, 621): 6-bromochroman-4-one was reduced with NaBH4 (1.2 eq, MeOH-DCM, 0° C. to RT, 2 h) and then eliminated with pTsOH (cat., toluene, reflux, 3 h, 90% for 2-steps). The resulting 6-bromochromene was subjected to osmylation (cat. OsO4, 1 eq. NMO, water-acetone-tBuOH, RT, overnight) and subsequent treatment with pTsOH (cat., toluene, reflux, 15 min, 86% for 2-steps) to provide 6-bromochroman-3-one (5A).
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
|---|---|
| Patent number | US08476274B2 |
| Source dataset | uspto-grants-2013_07 |
| ORD ID | ord-3dad9be9879c49c19eb5457bd90dc1e0 |
| Source note | uspto-grants-2013_07 |