Phosphorus pentachloride → (-)-Benzyl-[1-[{2-(o-chlorobenzoyl)4-nitrophenyl}carbamoyl]-ethyl]carbamate

HRID 437333Notes

Reaction equation

[C:1]([NH:11][C@H:12]([C:14]([OH:16])=O)[CH3:13])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2].P(Cl)(Cl)(Cl)(Cl)Cl.[NH2:23][C:24]1[CH:38]=[CH:37][C:36]([N+:39]([O-:41])=[O:40])=[CH:35][C:25]=1[C:26]([C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][C:29]=1[Cl:34])=[O:27]>O1CCCC1>[CH2:4]([O:3][C:1](=[O:2])[NH:11][CH:12]([C:14](=[O:16])[NH:23][C:24]1[CH:38]=[CH:37][C:36]([N+:39]([O-:41])=[O:40])=[CH:35][C:25]=1[C:26](=[O:27])[C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][C:29]=1[Cl:34])[CH3:13])[C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][CH:10]=1

Participants

Conditions

Temperature: -40 °C

Procedure

82 g of carbobenzoxy-L-alanine are dissolved in 100 ml of absolute tetrahydrofuran, the solution is cooled to -40° C and treated with 80 g of phosphorus pentachloride. The mixture is stirred at -30° C for 20 minutes and subsequently added to a shaken solution of 80 g of 2-amino-5-nitro-2'-chlorobenzophenone in 100 ml of absolute tetrahydrofuran. The solution is concentrated on a rotary evaporator at 50°-60° C, treated twice with toluene and evaporated each time. By crystallisation of the residue from ether, there is obtained (-)-benzyl-[1-[{2-(o-chlorobenzoyl)4-nitrophenyl}carbamoyl]-ethyl]carbamate which melts at 147° C and exhibits a rotation of [α]25D =-18.2° (in methylene chloride, 1%).

Workup

concentrationThe solution is concentrated on a rotary evaporator at 50°-60° C
additiontreated twice with toluene
customevaporated each time
customBy crystallisation of the residue from ether

Sources & evidence

ORD record: ord-24f2112d31fa425b90dd0bbbc07ea22d
Source dataset: uspto-grants-1977_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04031078

Reaction notes

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