Aminoacetaldehyde dimethyl acetal → HCID 178495874, compound

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Reaction Steps

Dissolve Benzyl N-(2-thioxo-1,3,4,5-tetrahydro-1-benzazepin-3-yl)carbamate (1.78 Kg, 5.13 mol) and para-toluene sulfonic acid monohydrate (48.8 g, 256 mmol) in dichloromethane (12 L). Add aminoacetaldehyde dimethyl acetal (2.70 Kg, 25 mole) dropwise over 1 hour and stir for 36 hours at ambient temperature. Add additional aminoacetaldehyde dimethyl acetal (1.40 Kg, 13 mol) and stir for 12 hours at ambient temperature. Add water (5.0 L), separate the organic layer, and extract the aqueous with dichloromethane (2.0 L). Combine the organic layers and wash with water, saturated ammonium chloride (6.0 L), and brine (4.0 L). Filter the organic through diatomaceous earth and concentrate under reduced pressure to give the title compound (2.30 kg, 118%) as a yellow oil: MS (m/z): 398 (M+1).

Provenance & Evidence