3- 2- ethyl 4-dimethy 1-3,6-dihydro

A solution of 0.7 g of 2-(2-amino-N-methylacetamido)-5-chlorobenzophenone in 10 ml of a 50% solution (by weight) of diketene in acetone is refluxed for 3 hours and then evaporated to give a brown oil. The oil Is chromatographed on 200 g of silica gel using a 1 1 (by volume) mixture of ethyl acetate cyclohexane 25 ml fractions are collected. Fractions 11-14 are combined, mixed with chloroform, evaporated and triturated with ether to give 0.337 g of 11-chloro-8,12b-dihydro-2,8-dimethy 1-12b-phenyl-4H-[ 1,3]oxazino[3,2-dl [1,4] benzodiazepine-4,7 (6H)-dione as a pale yellow solid, MP 174°C to 176°C. 

H-l,3-Oxazin 3,5-Dimethy -2-ethyl-3,4-dihydro- E14a/2, 744 (En-N-En + CH20) 4H-l,3-Oxazin 2-Methyl-6-propyl-5,6-dihydro- E5, 824 (4-OH-l-en + R —NC)... 

Benzoxazol 2-(l,l-Dimethy]-2-propenyl)- E8a, 1150 [Cl -> C(CH3)2-CH=CH2] lH-Carbazol 4a-Hydroxy-2,3,4,4a-tetrahydro- IV/lc, 483 Cyclobutan 1-Benzyl-l-cyan-3-hydroxy- E17e, 67 [(2-CN-ethyl) — oxiran + R —MgX] Cyclopentan-(spiro-2)-2,3-dihydro-indol - -3-oxo- VII/2a, 1051 Cyclopropan 2-Cyan-l-methoxy-2-methyl-l-phenyl- E17a, 764 (RO — CAr = Cr + En)... 

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