Hexane → 2-Azaspiro[4.5]decane-3-carboxylic acid

6.4 g of butyllithium (in the form of a hexane solution) were added to 16.7 g of butyliminomethylcyclohexane in 300 ml of anhydrous dimethoxyethane at -76° C. under protective gas (argon). 15 min. after completion of addition, 18 g of N-acetylchloroserine methyl ester in 100 ml of DME were added dropwise, with efficient cooling. The mixture was stirred for a further 1 hour at a low temperature, allowed to warm up and evaporated to a small volume in vacuo. The crude mixture was acidified with 200 ml of 2N HCl and heated to reflux for 45 min. The mixture was evaporated in vacuo, the residue was taken up in glacial acetic acid, 1 g of Pt/C (10% Pt) was added and hydrogenation was carried out under normal pressure. The mixture was filtered, evaporated and chromatographed over a silica gel column with the system chloroform/methanol/glacial acetic acid/water 25:15:2:2. The amino acid crystallized from the appropriate eluate after evaporation.

1. additionwere added dropwise, with efficient cooling
2. temperatureto warm up
3. customevaporated to a small volume in vacuo
4. temperatureheated
5. temperatureto reflux for 45 min
6. customThe mixture was evaporated in vacuo
7. addition1 g of Pt/C (10% Pt) was added
8. filtrationThe mixture was filtered
9. customevaporated
10. customchromatographed over a silica gel column with the system chloroform/methanol/glacial acetic acid/water 25:15:2:2
11. customThe amino acid crystallized from the appropriate eluate
12. customafter evaporation

ORD record

ord-a1fb4446e6a84726ab0bdba1ea0cc328

Source dataset

uspto-grants-1985_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04558064