Sulfuric Acid → 1,3-Dihydro-3-methyl-2H-3-benzazepin-2-one

HRID 2376618Notes

Reaction equation

HRID 2376618 reaction equation
OS(O)(=O)=O.[CH3:6][N:7]([CH2:17][CH:18](OC)OC)[C:8](=[O:16])[CH2:9][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>>[CH3:6][N:7]1[C:8](=[O:16])[CH2:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=2[CH:18]=[CH:17]1

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 3423225N-(2,2-dimethoxyethyl)-N-methyl-2-phenylacetamide

Product 1

HCID 598557731,3-Dihydro-3-methyl-2H-3-benzazepin-2-oneYield 100.1%

Conditions

Temperature
110 °C

Procedure

To a 5 L Morton flask under a strong nitrogen atmosphere was added H2SO4, (1.42 L) and N-methyl-N-(2,2-dimethoxyethyl)phenylacetamide (712 g, 3 mol) was added dropwise to the reaction flask which caused an exotherm (22 to 78° C.). The resulting reaction was then heated to 110° C. for 3 h then cooled to room temperature and transferred to a 20 L Morton flask. At less than 10° C., the reaction mixture was quenched with aqueous sodium hydroxide (9.18 L, 5 N). Extractive workup with ethyl acetate (2×2.85 L), drying with sodium sulfate followed by concentrating to a solid, provided 520 g (73.5%) of 3-methyl-2,3-dihydro-1H-3-benzazepin-2-one as a solid. This material may be recrystallized from MTBE for added purity to give a solid, mp=81-82° C.; (M+H)+=174.2.

Workup

  1. additionwas added dropwise to the reaction flask which
  2. customan exotherm (22 to 78° C.)
  3. customThe resulting reaction
  4. temperaturethen cooled to room temperature
  5. customAt less than 10° C., the reaction mixture was quenched with aqueous sodium hydroxide (9.18 L, 5 N)
  6. dry with materialExtractive workup with ethyl acetate (2×2.85 L), drying with sodium sulfate
  7. concentrationby concentrating to a solid

Sources & evidence

ORD record
ord-156fbb83b0404a8eb25b7ce409d85574
Source dataset
uspto-grants-2008_12
Patent number
US07468365B2

Reaction notes

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