Water → HCID 136395964, compound

Participants

Reaction Conditions

Reaction Steps

Compound 7a (1.02 g, 3.0 mmole) was dissolved in 30 ml of DMF. To this solution were added ethyl cyanophosphonate (1.62 ml, 9 mmole) and triethylamine (1.23 ml, 9.0 mmole). The mixture was heated to 80° C. for 2 minutes. After the mixture had been cooled to room temperature, a solution of diethyl L-glutamate hydrochloride (0.72 gm, 3.0 mmole) in triethylamine (0.42 ml, 3.0 mmole) was added to the mixture which was then stirred at room temperature for 48 hours. At the end of 48 hours, 150 ml of water was added to the mixture which was then extracted several times with chloroform. The organic layers were combined and dried over Na2 SO4. The chloroform solution was filtered, and the filtrate was evaporated to dryness. The residue was chromatographed on a silica gel column which was eluted with CHCl3 :ethanol (4:1). After the eluent was evaporated, the crude product, diethyl 4,7-diamino-N-10-methylpteroylglutamate was obtained as a yellow solid. Recrystallization from ethanol gave 0.5 g, corresponding to a 40% yield, of diethyl ester of 7-aminomethotrexate. The melting point of this compound was 210°-213° C. The IR spectrum (KBr) showed absorption signals corresponding to NH2 at 3108-3451.2 cm-1, aliphatic --CH at 2986.0 cm-1, --C(=O)O-- at 1727.9 cm-1, and --C=N-- at 1605.5 cm-1. The nmr spectrum (DMSO-d6) revealed signals at 8.30 δ (1H,d,CONH), 7.78 δ (2H,d,arom), 7.18 δ (2H, s,NH2), 6.50-7.0 δ (2H,b,NH2), 6.80 δ (2H,d,arom), 6.60 δ (2H,s,NH2), 4.65 δ (2H,s,CH2N), 4.30 δ (1H,m,NCH--), 4.10 δ (4H,q,COOCH2CH3 ×2), 3.20 δ (3H, s,NCH3), 2.45 δ (2H,m,CH2 CH2COOEt), 2.10 δ (2H,m,CH2CH2COOEt), and 1.20 δ (6H,t,OCH2CH3 ×2). The FAB mass spectrum showed a molecular ion peak at m/z 526. This peak confirmed that the molecular weight of this compound was 526. Elemental analysis of 4,7-diamino-N-10 methylpteroylglutamate confirmed a chemical structure corresponding to C24H31N9O5.H2O.

Provenance & Evidence