N-ethyl-N,N-diisopropylamine in dichloromethane under Ar; react. in CH2Cl2 for 4-6 h; partitioned between H2O and CH2Cl2, aq. layer was extd. with CH2Cl2, combined organic ext.were washed with brine, dried, volatiles were removed in vac., chromy. on silica gel;