Ammonium Chloride → tert-butyl (S)-3-methyl-2-{[cis-3-(5-methyl-2-p-tolyloxazol-4-ylmethoxy)cyclohexylmethyl]amino}butyrate

Participants

Reaction Conditions

Reaction Steps

511 mg of cis-3-(5-methyl-2-p-tolyloxazol-4-ylmethoxy)cyclohexanecarbaldehyde, 0.9 ml of HOAc and 310 mg of tert-butyl (S)-valinate are dissolved in 5 ml of abs. dichloromethane. 500 mg of molecular sieve 4 Å are then added, and the suspension is cooled to 0° C. 414 mg of sodium triacetoxyborohydride are added a little at a time. This suspension is stirred at 0° C. for 2 h, 3 ml of saturated NH4Cl solution are then added and the suspension is stirred for a further 10 min. In each case 10 ml of water and dichloromethane are added, the phases are separated, the aqueous phase is extracted with dichloromethane and the combined organic phases are dried over MgSO4 and concentrated, which gives 760 mg of tert-butyl (S)-3-methyl-2-{[cis-3-(5-methyl-2-p-tolyloxazol-4-ylmethoxy)cyclohexylmethyl]-amino}butyrate. C28H42N2O4 (470.66); MS (ESI): 471.50 (MH+).

Provenance & Evidence